Group Buy: 3x8 Throttle Body Mod + Plenum Mod

i'll also be curious on the "umph" factor-seat of the pants feel, if there is one.

 

Tommy already has it on his car (and he paid for it), I am curious why we haven't heard from him on the "umph" factor and the great improvement it must have made????

 

I’ve never been able to “feel” anything that’s much less than a 10% change. I don’t believe we’re talking about anywhere near 10% here, as noted by my pool pick of 4 hp or 1.7% increase.

There are still plenty of good numbers left in the pool, so place your bets

 

I would love to know how a 4 hp increase on a Dyno cab be attributed to a device or just normal differences between runs. If you take the same car and run multiple dyno passes you will see variances of 2 to 5% and maybe more.

If Mark is on the money then for $600 you get a 4 hp gain? thats insane!

Put two light weight euro bumpers on your car (for less) and gain the same performance change and the car looks better as well.

 

Go to an aluminum radiator and lose another 25+ pounds....about $600 and far better cooling as well

 

Doing the math using F=ma so a % change in wieght or hp give the same result in acceleration:

Alum Radiator costing $600 and saving 25 lb on a 3200lb car will improve the acceleration by 0.78%. making the improvement 768$/% improvement, but it has other benefits too I guess.

Adding a euro bumper costing $600 and saving 40lb gives a 1.2% improvement or 480 $/%

The throttle body costing $600 and adding 1.7% more hp (to pick a number) give 353 $/%, making it the best value of all the suggestions made.

The EFI or carb conversion should cost about $3000 and add 10%, so it comes in at 300 $/%. So that’s better yet.

After you have carb/EFI you can add $2000 cams that will give you say 20hp giving 260 $/% (assuming the power went up to 260 hp when you did the EFI/carbs), pretty good.

Going with EFI and a turbo or SC should be about $10000 and add say 50% giving 200 $/%.

Adding an intercooled SC/turbo should cost say $12000 and give a 100% hp increase yielding 120 $/%, so it’s by far the best spent money for power that’s always there.

Adding a 100 hp Nitrous system should cost under $1000 and is a 43% hp increase, so 23.5 $/%. That is why there is so much talk of nitrous, it can’t be beat if you just want a little speed now and then.

 

As far as the "umph" factor goes; not much but, then again, I wasn't expecting much. I love bolt on goodies so I do them all. I never made ANY claims about it before or since. Folks who drive my car say it feels stronger than their's but usually it's against cars with stock exhausts, etc. I don't give the TB the credit. The test pipe, K&N and Tubi, I think, make the very small difference. It is a bit lighter too. I have a Euro spare, Brembo kit up front and, of course, the Tubi is MUCH lighter. I think that should all add up to about 30lbs.

 

If you pick any number (even if it is your guess) of course it would be the best value.

The logic of your post is silly in the above respect the rest is very good.

By the way the Fiberglass euro bumpers save some 75 lbs Not 40 lbs thus being the most bang for your buck (items under $1000) even if you use your made up numbers on the TB.

 

if this is a true story on Mr morgan this man is a fraud.

 

I did some looking online a while back in regards to aluminum radiators vs brass/copper. What I came to the conclusion of, is that its very difficult to beat copper. Its stronger, and by far a much better conductor of heat. So while it is heavier, there are other factors with aluminum that make the apparent difference not so far apart. Because aluminum is both not as good of a cunductor of heat, nor as strong, the tubes have to be round, and thicker, and more of them, so the entire core has to be thicker to get the same heat loss. Because the tubes have to be larger, the volume of coolant inside when its full, far exceeds the capacity of a copper radiator. Coolant being over 8 pounds per gallon doesnt take much to knock away your weight savings. Then there is the factor of corrosion, with aluminum being far worse. My copper radiator is 28 years old and in fine shape. My old ford tractor had a radiator that was over 40 years old. Some copper radiators are over 75 years old. Aluminum will never approach those ages.

Using that math example, I compared the 4.1 liter engine project, making a realistic 350 HP, and figuring you could achieve 275 HP with a stock 308 2 valve with maybe $5000 in upgrades, your have at best maybe a 75 HP increase while spending far in excess of $20K. But being somewhat fair, we could say $15K for 75 HP is $200 per HP. But more realistic would be to double that amount. That dumb throttle body, if it makes 4 HP, really isnt a bad purchase. How does one throw thier money in on this bet? I will also go $10 it makes 4 HP or more. Who will be the judge?

 

As alluded to in a previous post, past a certain amount of engine modifications, time/money is better spent on 'adding lightness'.
The real challenge of the 30X and especially Mondial cars is their weight.

 

plus lightness makes the car behave better in cornering and braking! so you'll get better lap times without compromising the engine's life and you'll get bragging rigths that a stock 308 engine being faster than one with a TB mod!

and less weight equals more tyre life, more bake pad life
if you make it go faster with the original weight brakes and tyres will pay for that!

 

You're right, the number was a guess....but we'll have the correct number soon enough. The point was really just to try to give a few examples of cost/benefit to help put the common modifications in the correct perspective.

oh, and I was giving 80lbs for bumpers, 40lbs per bumper.

And last of course is the number are for acceleration only. as other have pointed out, reducing weight has other advantages as well...but it's almost always easier and cheaper to add hp

 

Copper is a better conductor than aluminum by about a factor of 2....but it isn't very strong and needs to be alloyed to make a radiator. The alloy commonly used is a brass, and brass is about the same as aluminum for heat transfer. The aluminum radiator ends up working about 2 times better than the brass though because the alum tubes can be made with higher surface area/internal volume ratios and the surface heat transfer is much better with alum so the heat gets in and out better. There are good reasons that OEM radiators are pretty much all aluminum these days. But you are correct, they will not live as long as brass.

There are other options. The intercooler I mounted in my manifold is a copper/nickel alloy and is about 2 times more effective than a similar size Alum unit would be....it's 3 of 4 times the weight, but in the manifold the space is limited and I needed the very best cooler I could fit.

I've already got 4hp in the pool, but I'll record you for 5 if you want. We'll do a closest to the number Mike/Tom get at the dyno wins...maximum gain or loss, the average if they do multiple pulls at both points. How's that sound?

 

True on most other cars but on a 308 the CIS limits you so dramaticly that weight reduction is a cheaper alternative+ the 308 has a ton of weight to shed.

The easiest way to gain HP (dramaticly) is to remove the CIS but that is expensive and requires a fair amount of skill to replace it with an alternative system. As I explained to Steven in a PM there is no one building bolt on induction or performance systems for 308's...because their are only a few of us that modify them.

For $650 and a JEGS catalog you can add an easy 50 hp to an American V8 but for $650 with a 308 you get MAYBE 4 hp (and I doubt that #)......that's just a waste of money.

Save your $650 and wait a year and hopefully you will have $2000 and you can start a FI project or a carb project.

Don't throw money at the CIS system as that is the biggest waste.

 

Why, technically, does the CIS limit performance? Does it fail to inject enough fuel? Fail to act fast enough for higher RPMs? Limits air?

It's well known that going backwards in time to carbs or forward in time to better injection systems adds horsepower to CIS Fcars, but what specific reason is in play?

Do the other systems simply omit the plate restriction of the CIS?

Or is it that the spark plugs don't get enough juice (or fast enough)?

Perhaps only the CIS shortfall, rather than the entire CIS system, could be addressed in order to save money??

 

Scan back a few posts and have a look at the diagram that was posted of the system..you'll soon see why it's a garbage system.

 

To me, a mere casual outside observer, the obvious weak points in the CIS would seem to be the sensor plate and the intake air distributor. Perhaps there are further weaknesses that I can't readily see from ROLOcr's picture (below), but if not...if those are the the main weak points, then one wonders if the CIS couldn't be improved by replacing/upgrading those two problem areas rather than junking the entire system.

Just a thought (not trying to start any wars...just trying to brain storm).
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The CIS was never meant to be a performanced based injection system, it was the best way for manufactures to meet the emission rules that came into place.

There were attempts in the early years to modify it for enhanced performance but they did not pan out.

It is just plain Archaic and again there is no market that would justify the engineering to try an improve upon such a system.

It has been out of production for about 15 years (I guess)

 

It's a classic case of "to observe is to disturb"

It's a classic case of "to observe is to disturb". Any system needs energy to operate. The CIS system draws energy from the air flow stream to control the fuel metering.

The only way to fix it, is to stop doing that. I guess it should be possibly to remove the mass air plate, replace it with an electric mass air sensor, then send the signal to a stepper motor to regulate the fuel meter valve. That would give you a system that works and makes hp, bit I think it would have twice as many parts as either the original CIS system or an EFI system.

 

Understood. How did Porsche ever put it on their 911's?!

The smaller engines used an 80mm sensor plate, correct? Porsche and Ferrari used a 110mm sensor plate.

Well, would an even larger sensor plate be better??

It seems as though Porsche and Ferrari agreed with my earlier casual observation that the sensor plate appears to be a key CIS weak point (with larger sensor plates being better).

Whatever injection system is used, in the end you are getting proper timing, proper air/fuel, and proper spark.

Is air the CIS weakness? Or fuel? Or spark? Or timing?

 

Even by looking at photos of the 308's engine you can really see how restrictive the sytem is. That big 'ol rubber tub looking thing is the air inlet to the thottle body..which in itself is of a poor design. Before the air even gets there..it has to travel through that god awful air box, through a 90 degree bend, then though the air filter, then the low pressure created by the engine draws the sensor plate down, and the air must travel around the sensor plate, which is a big blockage, then it must make another 90 degree bend in the airflow meter casting, and another almost 90 degree bend up the tube to another almost 90 degree bend trough that stupid tube, then into the throttle body and finaly into the intake plenum. Its a wonder the damn things run aswell as they do!!

If you look at other CIS cars like a Benz..the path that the air must take is no where near a bendy or restrictive as the Ferrari is. On the Benz units..the TB is directly under the sensor plate which really helps things alot. Even the TR with its set up is far better then what Ferrari did with the 308 series.

A great example of how Ferrari should have don the injection on the 308 series is the Lancia Thema 8.32..twin TB's.

 

Perhaps...and perhaps there is a leverage effect in play here that isn't obvious to the casual observer...but if no leveraging is in play, then I'd have a difficult time accepting that more than 1 or 2 HP were required to lift the sensor plate.

Moreover, I think that everyone would have to agree that it would take *more* effort to lift the larger 110mm sensor plate than the 80mm sensor plate...and the 110mm sensor plate delivers more HP.

Well, what would a 140mm sensor plate deliver (if it could fit)??

One added point: the Porsche 928S "Euro" models used the K-Jet CIS system and delivered 310 HP. Not bad for 1983 (on a system not designed for performance).

 

Mr Paul Sloan.

Please stop sending me private messages to either attack me, or present your lame cases against all you disagree with. As for my model T 308, as you refer to it in this private message you sent me, I and many here appreciate our Ferrari just the way it was made, and I make no excuses about it. If you want to argue about alloys in radiators, I really could care less. Copper, brass, or bronze, I really dont give a rats butt. There are litterally thousands of sites that discuss radiators and in the end there just isnt a great deal of difference. And while you are laughing so hard at all of our Model T 308's as you refer in your message, I couldnt even begin to describe what I and a few others might think of your "creation".

Now if you really want something to answer a question to, I can ask a few I doubt you would ever answer. But hear me LOUD and CLEAR, Paul, DO NOT MESSAGE ME AGAIN, OR SOMETHING WILL BE DONE ABOUT IT!!!