Supercharger | Turbo

I do understand and they are completely rpm depenant because they depend on the enpine they are attached too (which has mostly alinear flow-rpm profile) the both provide exhast flow for the turbine and to accept the air flow from the compressor.

There are TS superchargers for any flow you want. To make 1700hp, guessing 1.4scfm/hp, you'd need 2300+SCFM, so off the top of my head I'd choose a W305Ax from whipple which flows about 2800scfm. To get more than that the cheapest thing would be fit a pair of w200ax blower, they will flow about 3200scfm. to do it with a single blower I'd have to dig a bit, but both lysholm (supplies whipple) and autorotor can make pretty much anythin specail order....remember they make the blowers that go on 8000hp+ top fuel engines.

A TS SC runs at about 65% efficient, so the discharge temp is prety much the same as with a turbo, no more heat than a turbo really.

To get 850rwhp from a SC 8 liter I'd guess the flow required would be about 1300-1400 scfm, so a w200ax should handle it...but I'd probably spec a w305ax just to be sure.

It's probable a good time to point out that I don't have anything against turbos and for many applications I think they are the best choice. I agree with you that a turbo will make more hp than a SC at the same boost.

the reason that most SC kits applications are not real high hp is because they are designed as low-boost bolt-on kit. That is where most of the market is, I know that is almost exclusively what the other ferrari owner ask me about. They want 30-50% which is easy to do with either a turbo or SC. If they tend to track their car a lot, I recomend a turbo, if it's more a daily driver, I recomend a SC. My 308 is a daily driver, so I SC'd it and am quite happy with the result.

When I say 2 or more, I'm talking about different size trubos. The point not being max hp, but smooth torque. A small turbo to make boost down low and a large one to handle the top end needs....I guess 2 the same would work too, the point was it would require some ECU controle valving, and adds a lot of complication. If a smooth torque curve is important, a SC is a good choice, itf not a turbo is a better choice. that was really the only point there.

All centrifigul unit have exponentail flow/output curves. a waste gate is a beautiful thing and does a great job of surpressing the true shap of the curve and makes a turbo a very useful device, much nicer than a centrifigul SC.

OK, A by-pass valve does sense vacuum between the throttle plate and the SC, and when it's there, it tranfers the engine vacuum driectly to the throttl plate. The reason is to imporve milage, increase the compressor life and give a smoother idle. Without a by-pass valve a SC will work just fine, but will lose a couple mpg. It has nothing to due with controloling boost, the throttle plae does that. It is most like a blow-off valve on a turbo, it's nice to have and the system is better with it, but it's not required and it doesn't conrol boost in any way.

[qoute]
Do you have any experience with centi supercharger systems? Honestly they do make more power on the top end compared to a TS, It's pretty simple to see that in just about every application around. Find an LSx and compare the magnusson setup to a procharger or paxton, not even a close comparison. I would quit studying the KB website so much, and take a look at what else is available. [/quote]

Yes. I had a couple freind who had them...they have both now switched to TS. they make great power on the top end, but a turbo is better at that. Most people who choose SC are looking for flat torque curves, a turbo can do that and a centrifigul SC is much worste than a turbo. I don't think they are ever a good choice.

there is almost no friction in a TS SC, it spins free. The hp goes to compressing the air and you are 100% correct, there is no getting around the hp draw and that is why a trubo why make more hp at the same boost. GMC type blower do have tons of friction and are are only about 40% efficient, I don't think there is any application I would spec one one those for.

You're also right that fitting under the hood is a big concern and sometimes means a turbo is the only practical choice.

 

Matthew,
See what you started???

I find this to be a very interesting thread, quite!

I think the debate will rage on and not just in this forum.

Regards,
Bill

 

Don't sweat it, nothing personal here just a good debate.

As for the TS being fairly friction free that has not been my experience. All the autorotors I have worked with (4 thus far) have been very tight. You could turn them by hand, but not enough where you could just spin and they would freewheel. These were on 2 mustangs (2.4L and 2.8L) 1 Viper, and one Ford V10 excursion. They felt very similar to the big X-71 setups, I'm sure they loosen up over time, but they were very very tight from the start. Take a look at any of the new BB turbos, you can blow on them and spin the impellers.

Even the guy with the 2.8L cobra which was making over 800rwhp was never satisfied with it. With a 10rib belt, 240* wrap, and purposely going to larger dia crank and blower pulleys to get more surface area it would still slip. Pretty disappointing when your being forced to run a cogdrive on your daily driver. That and boost was never very consistant, Air density had a huge effect on it, go to LACR where the elevation is over 3k ft and it was down. Turbos don't have any of those problems

Compounding turbos is down right foolish if your making under 30psi. If it's required to cover the rpm spectrum the whole setup has major issues. You will only see compounded turbos on diesels making 70+psi, some are well over 200psi now, that I can see for just sheer pressure, but other than that it's pointless.

Where have you ever seen a dyno pull started at less than 24-2600 rpm ? Your making wide open pulls in a tall gear (what ever is 1:1) Doing that at 2000 rpm on a FI motor is asking to blow it up. Not a problem in lower gears where the motor can rev freely, but you just don't lug a motor down in the low rpm range unless your goal is to kill it, this problem goes up exponentially as HP increases. Working with 4 digit HP numbers you just don't give it a chance to lug down low, if anything happens and it burps, or w/e, you just sent the heads into orbit. That goes for any FI car, SC, turbo, and especially N2O

If it's absolutely important to make 12psi at 1600rpm then your obviously not looking for any type of serious top end performance. The turbo cars i've worked on (with the exception of one) were pushin the waste gate by 2400rpm. Unless i'm on the fwy I don't generally accellerate at lower rpm than that so it works out great, and more power is only a clutch pedal away. The one car I have worked with that didn't make huge boost down low was a race car and it didn't much matter. When you have a 96mm GT88 on a 302 you can't expect it to make power below 4000rpm, but with a 4500 stall converter pulling to 9500 at over 1khp thats all ok.

All the things your describing were issues in the years past, with the advancement in technology, materials, and just general experience many are just a thing of the past. It's not uncommon to see a well designed system with a car running at idle, and hear the turbos whistling, slaming the boost gauge with just a hint of throttle.

It's pretty simple to see, look at all the quickest and fastest cars around. Be it pump gas, race fuel, drag or road racing, if turbos are legal they hold the records.

Short list:

Only 7 and 8 sec true street cars, Single turbo supra, 8.99 6 spd and 8.50 auto, twin turbo viper, 7.99 auto, 8.56 6spd. Fastest SC Viper barely cracked a 9, and i'm not sure a SC supra was ever built.

First ProMod in the 5's... big turbo car, SC and Nitrous cars had 15 years to play around and never hit it.

HotRod pumpgas drags 05'. Just so happend to be the same TT viper, on pump gas and drag radials running 8.50's at near 180mph. Not a supercharged car even in the field iirc.

Even production cars, TT benz, Porsche TT and GT2, F40, Saleen S7 TT. Now what were those things that Heff stuck on Waynes Gallardo... ahhh thats right, Turbos, and make what, 650rwhp at 7.5psi? Then there is this guy I know, John Meaney (you might have heard of him, does a little work in the tuning biz) built a TT setup on his daily driver 84 vette. Makes a measly 1200hp on pump gas, and runs smoother than stock. His car along with another TT he built for a car called Chicayne, have been regarded by the top people in the industry as some of the best street cars to grace the roads of the world.. ever.

And all that is just dealing with power, leaving out how much more comfortable of the drive turbo cars are. As much as I love the loud rumble, loping idle, of a cammed up SC car, there is something to be said for having 1200rwhp and a car that sounds stock at idle, and all the way up till the point people think you have a Rolls Royce turbine under the hood, and the guy who thought his 300hp SPORTBIKE was fast, is nothing more than a headlight in the rear view mirror.

I'm trying to remember the exotic SC cars... well there is the GT40, which has what is basically a souped up truck engine, and like to blow sparkplugs out of the cylinder heads.

MB has the SL55, but it's a distant second to the 600 and 65.

Hmmm, well there are mustang cobras, but even those guys are tossing the blowers in favor of turbos.

I would like to believe that SC's are only giving up 50hp, but truthfully it's a lot more than that as the RPM increases. Combine that with the raised intake charge temps, inconsistant pressure, belt slippage issues, and pain in the ass packaging, thanks, but no thanks.

Sure SC are great if you want huge boost from idle to 2200rpm, we all know races are won and lost there, for those who don't know how to drive it might be.

A racer friend of mine gave me a good analogy for this one. When all is said and done one makes you think you d*ck is bigger, the other makes you buy pants 3 sizes larger to fit it in.

And i'm working up some actual data to backup the efficiency, IAT, boost rpm claims, so it's not all b/s.

 

That could very well be true, I haven't ever had an autorotor in my hands. The eaton's I've handled spin free, the lysholms (whipple) do have a slight drag when new occationally, but spin free after they've been run. I don't really see it as significant though, the worst one I've ever seen spun easily with a 1/3 hp drill, so it's less than a 1/3 hp loss.

Oh come-on now...in the last post you said a SC couldn't make 850rwhp on an 8 liter engine, now you're talking about a 2.8 liter making 800? Make up your mind here, can a SC make hp or not?

Seriously though, you make a good point about the belt. It is a critical part of a SC system and can be a pain to get right, especially with high boost set-ups. SC shine the brightest in modest boost application and most every kit I've ever seen is design for 8 psi or less for TS SCs, and 5 psi or less for roots types. Low boost doesn't put a huge load on the belt and that is what the manufactures are use to specing, I've found they tend to WAY under spec the belts for higher boost set-ups. When I did my first eaton set-up, the supplier said 6-rib was the way to go and I could go as small as 2" pulley on the blower. What I found was that 8 ribs and 3" blower pulley was the absolute limit, and that was just for a non-intercooled 10psi, 300rwhp setup. The 420 rwhp set-up I'm using now has a 10 rib belt, 3.5" blower pulley, 210+ degrees of wrap and a very tight belt to work. The 600 rwhp system I building now will be 14 rib with a 4.5" blower pulley, but ribbed belt are readily available up to 20 ribs, so we see what works.

Don't tell me, tell the factories fitting multiple turbos to low boost applications. I would just spec a SC and be done with it

You've spent too much time in turbo land, which is the only place dyno runs don't start at idle, or just above. I've literally see thousands of dyno pulls from under 1000 rpm on low revving US type engines. My 308 idles at 1200, so I usually start the dyno pull at 1500, although my last run with the car was at 2000 because I thinking about an ignition problem I was having and not wasn't paying enough attention to rpm, but I'll post it.

Now I think you concern about low rpm begs the question are any of the engines you're talking about actually safe to drive on the street? Seriously, a dyno doesn't load the engine any differently than pushing the gas pedal on the road....and if you are saying the engine will explode if you push the gas before you hit 2400-2600 rpm, that sounds very un-safe. If it's a US engine that redlines at 5500 or there about, so you're saying it is unsafe to operate the engine below 1/2 redline, it sounds almost useless anyplace except the drag strip. Am I misunderstand what you're saying?

The only reason I've ever seen dyno runs start at high rpm is because the engine builder or owner just flat don't want to see the ugly truth about what lies below that. To be fair I know a lot of people that love the rush of power they feel when their turbo car hits the boost threshold and just takes off, they love it.

Others, like myself, see that as a flaw. I thing big changes in torque over a few hundred rpm is dangerous on the street. I believe that the absolute safe limit is a 100% jump in torque, by that point the car gets pretty unstable going around a turn while the engine is crossing the boost threshold. That means that boost form a turbo has a safe limit of 15 psi on a true street car...which coincidentally is about the highest boost any OEM manufacture lets a car out the door. There is a big difference between what you can do and what you should do sometimes, and high boost turbo street cars are one of them IMO.

Personally, I'm unhappy with the step in the torque curve of my 5 psi turbo street car and I probably won't ever buy another one. On the other hand my 22 psi SC street car has a flatter torque curve than the engine did stock, I would have another Sc engine anytime. But that is a personal preference, and I'm not saying anyone who prefers a turbo is wrong, I just saying I don't.

Not from a turbo anyway, but a SC has no problem with it and doesn't require a 4500 rpm stall converter....I won't call that a street car.. You're right though, many people are perfectly happy to make the down shift and get the revs up to where they make power. I generally couldn't be bothered and perfer to have power at the rpm where I'm driving.

This is really the problem, IMO you are talking about street legal race cars, or just flat race cars, none of which really have any business on the street IMO. If I were building a race car, a turbo would probably be on the shopping list, depending on class, rules, ect. Roadracing or rally I'd want a turbo, autox I'd want a SC, drag racing I don't know, it's of almost no interest to me and I've honestly never though much about it....although I do like to watch top fuel when it's on tv, amazing machines.

I'm talking about street cars that can be driven safely. 400 rwhp will spin street tires right up to and well past the speed limit in every state. So on street tires, not street drag radials but street tires, a 2000 hp car isn't any faster than a 400 hp car (equal weight of course), it's just a big waste of time and money. I am building a 600rwhp set-up for a guy, I tried very hard to talk him down. I got him down from 800 to 600 by telling him that the engine will blow up, but the truth is I won't build a street system of him or anyone else with more than 1rwhp/5lbs because IMO it's stupid and dangerous and I won't have any part of it, so for his 3000lb car, he gets 600rwhp, no more. I built a couple things in my younger days that nearly killed people and I like think I've learned from that. I've noticed the guys at Norwood (who are known for turbo ferraris) try very hard not to let a street car go out the door with over 15 psi boost these days because they learned the same lesson the same way... except theirs did kill a couple people. I won't help anybody build a machine that I believe is un-safe or intented to be used in an unsafe way, like a million hp street car. There are prenty of others that will I guess, but at least I can sleep well at night.

 

oops, forgot the graph.

It's not a record setting race car engine, but it is a pretty nice street car engine IMO and is fabulous at the autox. I keep talking about turning it up to 500rwhp which was the original goal, but I'm so happy with it the way it is, I just never seem to bother, maybe next year.....I know, I'm getting old leaving hp on the table, but a nice driving car just means more to me than numbers these days.

...oh and yes I've fixed the skipping up top (and the thottle -on lean at the beginning), that the ignition problem I mensioned in my last post. I guess I should re-dyno it, with the mis fixed,I guess it's probably picked up 15-20 hp.
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I should have clarified, 2.8L was the size of the supercharger, on a 4V mustang mod motor,. 4.6L

Nice, so to make just 600rwhp it requires a $150 custom belt. Good luck when that one shreds.

Driving a low rpm is fine, making wide open runs from low rpm is fine if the motor is free to rev. But no I would take a car thats making 800+ rwhp, drop it in 4th gear just above idle, and proceed to make a wide open run. Same reason I wouldn't do it on a nitrous motor, your just asking for problems.

To generalise a boost number that is safe for street use is down right silly, and there are more than a few street cars that off the lot push much more than 15psi. And no I don't think a ramping boost curve is dangerous, it's the inexperienced driver behind the wheel who is dangerous. And there are plenty of 1000rwhp pump gas cars that are perfectly streetable. Take a look at www.garyjavo.com, his TT srt-10 makes just over that on pump gas and works great as a daily driver. With no traction control or staged boost controller ran 10.40 @ 148mph on 20" pilots, doesn't get much more street car than that.

On that particular car it wouldn't ever achieve those HP figures with a blower, and being the general nature of a 302 they do require high stall TC's. To make that kind of HP from small cid you need a lot of boost and a lot of rpm. That requires a healthy cam, and a large port head, SC or not all that pushes the torque curve farther up the RPM range. There are many, many SC cars that run high stall converters, and a SC that could keep up with that turbo would eat 150hp doing so. I've never seen a 12-71 TS mounted to a sbf, and I would venture to say there is good reason for that.

400rwhp will spin the tires if the car has a piss poor suspension setup and inadequate tires. There are plenty of street cars that make double that and hook up just fine on the street, it's all in the setup and tuning.

And it's silly to blame the car for the drivers actions, people are killed doing stupid things in 200hp cars just as much as 2000hp cars. If the driver doesn't have the sence enough to know how to handle the car, but still wants to push it, thats his problem. But to that extent if your building the car why not use a staged boost controller to limit power in lower gears? There is nothing wrong with having various boost programs, for pump and race gas, and they can, along with some of the new traction control systems, make it very easy to drive 800rwhp cars.

But I guess thats just the difference in a true enthusiast who is willing to learn how to drive the car, control, and respect it's power, and some middle aged CPA who wants a 600hp car so he doens't look like such a tool with his windbreaker and combover.

 

Either way, the point being is it is very possible to make the numbers. One thing to note is that with the blower mounted tot he intake, it's hard to do a good job intercooling. Most SC systems don't bother making much of an effort because they are designed for 4-6 psi and don't require it.

A single belt works best and is good for 5 years or 100,000 miles just like any other belt...unless of course you size it all wrong and fry it. In a pintch pair of 5, 6, or 8 rib off the shelf belts will do just fine if $150 is an issue....but I guess if $150 is an issue they don't drive a ferrari either. As I said before, selectingthe right belt is important and not easy...the size of the SC isn't all the important as long as it's big enough, but the belt is and as you seem to have found out, it makes all the difference. Pick the wrong belt and you will have a sh*t system that's nothing but problems. The right belt design is as important to a SC system as selecting the right turbo is to a turbo system.

If that's true, you are building grenades not engines IMO. There’s really nothing else to say there.

Talk to me again after you hurt or kill some one, because you will. Clearly "perfectly streetable" is in the eye of the beholder.

I find that very hard to believe and I'm going to have to call BS on that one. Give me a baseling dyno graph and 1 day and I'll spec a SC system to make any number you want....if the number is unreasonable the engine will explode, but if it's been done with a turbo, it can be done with a SC, all it takes is money.

Now we're back to "perfectly streetable", as I don't consider a torque converter with a stall speed much over 2500 suitable for the street.

Last, A GMC 12-71 is a roots type blower, not a TS....that might be why you;re having trouble making the numbers with it.

Dude, it's a ferrari and it wins autocrosses, there is no suspension problem. Yes, I believe that with drag radials, and trotally unsafe on the street drag suspension you can hook 800rwhp. but then it's a drag race car isn't.

You're right, people will be people, but imo there are very very few that can drive an 800rwhp car to it's limits....and most of them have an F1 contract. I could absolutlety add traction control and limit the power in the lower gears (with a SC it's done with solidiod throtle stops, throttle by wire, or timing maps), but I don't see the point? Why would I build an 800hp engine and then only give you 400? Seems a big waste of money to me. I might set-up a street/track car like that I guess, but with an SC, they usually just ask for 2 pulleys and change it at the track.

I'm not that worried about the enthusiast who build and understands the car whether he's a CPA or ditch digger, I'm worried about who else might drive it, which is how 2 that I built end up in guardrails and trees a few years back. I don't build those any more. I'm also worried about the semi-enthusiast who has the money to buy the car and not a clue what the implications are. I just don’t build stuff for the street that doesn’t belong on the street, meaning it brakes and turns well and the power is smooth predictable. I truely hope never to be on the same road with some of the car you’ve described.

 

Oh no...the other day when I went to the whipple site to spec a blower fot he 850rwhp viper question, I noticed the models were new.

I took a closer look tonight and it looks like the effeciency of the 2300cc unit is now up to 80% from 65% that mine makes and the flow is up a bit too, as is the redline, but the main time is the flow appears more linear. They've got a dyno sheet with back to back runs and they engine has the same bump in 2/3 of the way up the torque curve mine does, but with the new unit it appears flat and the whole curve shifted up quite a bit....I like flat torqure curves......I may just need a new blower.

Any one interested in an ax2300 with low miles on it?

The graph is almost too small to read, but here it is blown up as best I can.
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I forgot to point out that the dyno pull and torque both start at 1000 rpm

 

What did you find for the viper? My calculation what that at redline N/A they use 1018cfm assuming 100% ve, standard street duty is 12psi, all out being 22+

So to hit the number there is one 5L blower that might fit the bill, but then how do you intercool it? As efficient as you would like to believe those things are, the charge temps will be crazy even at 12psi.

They don't list dimensions, but i'm guessing a 5L is rather huge, so how do you you fit it under the hood? Buy a non-existant cowl hood, or cut a hole in the stock, $15,000 hood?

And the stock 7 rib belt is never going to hold that kind of pressure, and good luck fitting a 12+ rib, oh but you can't, with out going to a dedicated blower drive pulley, which is far from easy w/o relocating the radiator and fan, and then modifying the hood hinge/support brace.

And even before you get that far, there is the custom intake manifold that needs to be built to mount the thing.

Nifty, so after all that your stuck with a less efficient, less adjustable, more problematic system, all to make boost from idle to 1800rpm. Yip sounds like a winner to me.

Granted the viper is an odd application, and making torque down low isn't a problem, they have over 500ft/lbs stock. But you see the point.



Now here's one, find a twin screw to fit the bill for this gentlemans motor:

Dart 351w SBF
Callies billet crank/rods
JE forged pistons, 8.5:1
AFR 227 heads, unported
242/256 @ .050, .640/.660", 114lca cam, 106cl
BS3 efi, going in a 3200lb (with driver) car
Needs to be tunable to run 12-14psi on pump gas, and 36ish on race gas.
Revlimiter is set at 8800rpm

Yes this car does exist, and it's street driven.

Currently running a single 106mm, air:air intercooled. Made 1267rwhp/ @7400 and 960ft/lbs, was still climbing but they ran out of injector. Should make 1300 easy, hopefully 1350 (on C16 race gas)

Even with such a radical setup it's a very capable street car, idles nice, isn't stupid loud, and still retains A/C, fits under a stock hood.


If making boost at idle is that important, you aren't capable of using a clutch, and you want to go through all the hassle of packaging an inferior compressor, then by all means go right ahead.

Even if you only plan to make 6psi, why bother with something that is so limited. Bump it up to 12psi and you start running into all kinds of problems, belt slippage, IAC temps through the roof, and a pain to adjust boost on a regular basis. I would personally prefer to not have to drop another $4-500 in custom pulleys/belts, and then go through all the fits of a meth injection setup cause it's just not feasable to stack an IC under the SC. And even if you built one air:water IC's aren't the best idea for a street vehicle.

Or you can drive to the track, dump some good gas in it, turn a knob to the desired boost level, and go run.

But it's ok, to some inferiority is perfectly acceptable, hey there are some people who don't like electricity or indoor plumbing, to each their own I guess.

 

The 5 liter blower should handle it pretty easily. I'm not positive, but I think it's the same height as the 3.3, which is about 6.25", but longer.

There are a few options on intercooling. You can put a water/air intercooler in the intake or discharge the blower to a pipe ans plumb it to an air/air just you do your turbo set-ups. The air/air cools a bit better but the water/air gives a bit better throttle responce. Either would work fine, it's just what is easier to plumb.

If space is a problem there are a few options. I’d probably try, 2 belts going to the blower. So keep the 7 rib around accessories and the blower, then add a second belt in front of that with what ever space you can find. If that won’t do, sometimes a jackshaft can be slid in the move the blower belt to where there is room. Sometimes a custom harmonic balancer/pulley combo will work. It can almost always be done.

A lot of times you can keep the stock intake an mount the blower on the side of the engine. That makes it really easy to intercool as well. If you can't, a custom intake's not that bad, I've built 1/2 a dozen now.

.

It's less efficient, but will only be problematic or non-adjustable if it's designed poorly and will produce a much wider usable power band.

There will always be plusses and minuses of any system and there is a lot that goes into picking the best system for any application. There are a lot of times I would pick a turbo over a SC, the point is that a hp goal isn’t one of the things that would drive me in one direction over the other.

Well, I think that 5 liter blower will be close, but will probably come up just a bit short. A pair of 3.3 liter unit should do it, but you should be able to specail order a single 6 or 7 liter unit if you prefer. I'd go with an air/air intercooler and make a 2 piece crank pulley so it's easy to crank when you get to the track

I don't know about you, but when I say street car, I mean street car that gets driven, sits in traffic, ect. I tend not to buzz through town with the engine at 5k, I'd say 95% of the time the engine in uder 3k and having smooth and available power is nice.

Well if you just bump it to 12, you didn't do a very good job of sticking to your plan to make 6 did you? The overwhelming majority of people just want to add 100 hp or so to there cars and they're happy. No tire, suspension, or driveline worries, no intercooler to mess with, just a simple 6 psi and a 100+ hp and they’re happy. They sell literally thousands of systems like that every year. Maybe 1 in 10 opts to go up to 12-15 psi and add an intercooler, but them they need a clutch, probably bigger tires, suspension and brake work.

Maybe 1 in a 1000 decides to build a racecar and up it past 15psi. That’s a race car, it’ll probably need valve springs, pistons o-ring the heads plus all the other general work tire clutch, ect, ect. That’s a race car no matter what you try to call it and most people want nothing to do with it.

When was the last time you saw a ferrari at the drag strip? At the roadrace track, most people can't handle the hp the car came with much less the 30-50% a basic system would add. They certainly don't need 100% in most cases. But if they do, it's just a pulley crank away. It takes me about 15 minutes to change the blower pulley.

Diversity is part of what makes the world a wonderful place and interior depends on what you’re looking at and for.

 

I forgot this part,
A A2V ford engine with enough cam and port to make peak HP beyound 7400 and rev to 8800 is going to idle at around 1500, and not start to wake up until 3000-3500, I'm thinking it also has solid lifters and is making about 500 rwhp before the turbo. I think most people call that a race engine whether the car has a plate on it or not. And since it's a 3200 lb car, I personally wouldn't give him any more power for the street, maybe 100hp, so 3 or 4 psi.

 

Anyone remember the electrically driven "blowers"?

If you're really looking for some "off season" fun, do a web search on "Tesla Turbines".

Convert those used computer disk drives to superchargers!

(Batteries not included)

 

Good discussion here.
Any thoughts on alcohol/water injection instead of an air/air intercooler?
Why are the superchargers running ribbed belts instead of a timing belt with teeth? I would think that these would provide a more positive drive without being tensioned to the n'th degree.

As an aside, it seems that the cost to do a 328 would be about the same to upgrade to a 355. At these costs, it seems that a car upgrade is more logical than a blower upgrade.

 

The big concern with liquid injection is that if you run out of fluid under boost you could gernade the motor in a hurry. Depending on how it's configured, a malfunction could also hydrolock the motor. In both cases it's a slim possibility, but it is there.

re: 355/328, these cars aren't logical in any case. Personally, I just want a 328 with more power

 

Ahhh thats one of the beauties of a well setup turbo, it doesn't need nearly as much cam as one would think to rev, and drastically tones down the attitude of the motor in general. In a SBF normally a 24x/25x @.050 cam is pretty big, but when you have a 114+ LCA and the turbo it makes things quite nice, idles well at 900rpm, makes plenty of vac to run the accessories and such.

And yes it does run a solid roller cam, don't see that as making it any less streetable? Unless you don't know how to adjust valves properly and they need constant attention.

 

Meth injection works very well when properly setup, but don't think I would make it the primary charge cooler for a street vehicle. Even setup as a staged injection system to only come in under a specific boost pressure it can get tricky. Having to custom tune the A/F ratio based on the meth, worrying about running out, and so on. And depending on what type of FI you have to be careful where you introduce it to the intake. With a positive displacement SC you can shoot it right into the SC and it won't hurt anything, with a turbo or centi SC you don't dare let any liquid hit the turbines.

 

I've never seen any FI system that shifts the power of the basic NA engine, the height of the peaks change and the shape of the curves changes a bit, usually for the worst, but it's the same engine.

When you said 8800 24x/25x I assumed you mistyped the cam spec because I never seen anything but a 4V engine make power to that rpm with those cam specs. I would expect a 2V to be all done by 7500...which isn't in disagreement with the dyno info you posted I guess. I guess a 900 rpm idle is probably about right for a 24x/25x, although 8.5 CR is pretty low, I'm still thinking flat on it's face until 2500-3000 (I know, I know, you don't consider that important).

I was thinking 8800 rpm 2v, like my harley that needs 270/270 to make peak hp at 8400 and pull to 87/8800 and needs 12.5CR to keep the bottom end up.

You're right, you can run solid lifter on the street, I've just never met anyone who choose that path more than once...adjusting valves a couple times a month gets old, but it works.

I think we're right back to a difference of opinion about what a "street" car is. Since it’s clear that neither of us will be converting the other, I guess it's best to just leave it at that.

 

Yeah....it never makes good sense to modify. If you have a machine shop, to buy everything you need to either a basic turbo or SC 6-10 psi system your still looking at $5-$6k. If you have to have machining done, $8K-$10K, it you have to have it installed figure $15k+. To get to 15 psi, add $2k-$5k, over 15 psi add $10K because you'll be inside the engine.

But the other way to look at it is a 328 at 15psi will be something like 350-400rwhp, a 355 is about 300, unless of course to add a turbo or SC and bring it to 600rwhp....it's a viscous circle

 

Actually that car runs quite a bit better down low than a comparable N/A motor would. Reason being is that to turn near 9k N/A you would need a cam in the 27x range and likely a 106-108 LCA, thats going to bleed off a ton of cylinder pressure down low and would likely idle around 12-1400.

You've never seen an rpm range extended from a turbo? Even on stock engines the stock cam normally proves to be very good, and providing the valve springs/pushrods can handle it, you normally find the rpm range extended by 1000+rpm, quite a bit more in some cases.

As I said, if you don't know how to properly adjust valves then yes you will be in there every couple weeks. My personal DD has been on solid lifters for the better part of 9 months now, checked them once 500 miles after install and haven't had the valve covers off since then. If they get sloppy something is wrong. Parts are either wearing out which is more of an issue than just an adjustment, or (most likely) mechanic error and his adjustments aren't holding. Don't blame the car for driver/mechanic errors and inadequacies.

 

No, never. I know it doesn't work out that way with any of the ferrari or harley dyno sheets I've seen, and honestly I haven't paid that much attention to other engines. I've got 308 graphs stock, SC, turbo and they all look pretty much the same. I also saved a F355TT graph someplace, I could dig it up - it was post here, but again, no RPM change that I could see....tons of power though. I don't have the turbo harley graph, but I could probably get it, my buddy did the work and dyno'd it before and after and just like the ferraris, it was the same graph before and after, just more power. If you got dyno sheets that do show an increase in RPM with no change other than the addition of a turbo, I'd be very interested to see them and whatever specs, I've never seen that behavior before.

How many miles have you put on it?

My race bike with solid lifters would lose about 1% hp per track weekend that would come back with a valve adjustment. I know my couple freinds that drag set the valves before the car/bike leaves the garage because they have also found it makes a difference. For some reason 5k miles pops into my head for the old chevys with factory solid lifts, but that could be all wrong...the older guy that sits across form me at the office says his old GTO with a solid cam wanted an adjustment about once a month to stay right, but they may be better now.....although there haven't been any OEM solid cams for about 40 years...hmmm.

You are the first person who I ever heard say they would have another street car with a solid cam. Which bring us back to the what a "street" car is debate.