taller 348 intake manifold

How much HP are the taller Euro ones really worth? 5-10? Anyone swap them? Hard to find? What about a spacer to add volume to the plenums?

 

I don't think they are worth very much because the throttle bodies are still the same size, as are the runners going to the head. My guess is maybe 2-3hp in the upper rpm range, if that. But to really know for sure we need a dyno comparison.

 

Tex,

I am working on a minimum cut solution for more HP. If you search FC you will see around 400+hp from just upper intak mods and etra fuel. Most of these numbers were gained by bigger TB's larger plenum and more air flow.

My solution would be more stock looking. I'm thinking about a 1" plenum spacer, hogged out pleunum opening, larger throttle body or maybe a hogged out one with larger throttle plate, TB spacer to smooth the airflow, larger hopefully bosch MAF maybe off another car that maybe was 3 L but one MAF. These mods would get us an unknown amount of HP and still look pretty stock. This is all in the thinking stage so far but if we have enough guys who want to try then we can get spacers etc and TB/plunum cutting.. machined at a much lower price per unit. It is even possible to weld up the oem plunum and cut the interior out for even larger diameter and there is plenty of metal to thin the intake runner as well.

Larger bosch injectors are easy and plentiful as is adjustable fuel pressure regulators if needed.

So what do you think of that?

 

......it may be a race to completion then.... this and other "intake" mods are already in the works with at least one fellow brotherhood member...... .........some pre-mod dyno runs have already been completed......!

 

Yeah I know had to miss out on that one. I got called into work that day.

 

I can see 348's becoming THE CAR to have, if such a bolt-on mod was readily available.

More HP than a 360, almost half the cost. Long live the 348!!!

 

All I can say is "HURRY UP ALREADY", and "WHERE DO I SEND THE CHECK"!!!!!!!!! ;o) Scott

 

FBB, I say lets do this, and I have to do an engine out soon anyway! Do you have stock dyno numbers already? Already know of the round carbon canisters to use to replace the stock air filter box.

 

I am not sure there is enough to be gained from the tall manifold but sure will help with the OS TB. I gave up on that direction and started in another.

This winter the IMSA "Flag" car is getting a flat slide valve intake coupled with the tall manifold. As I am not measuring any airflow I decided this would be the best direction as I can then run unobstructed and plot a new fuel curve. The sprint engine is also getting freshened and moth balled and the enduro engine installed so I can find a way to street drive the car. Now that I own the car I want to use it for club drives / track so I have to find a way to install lights, muffler, removable windows.... to make it comfortable enough for Kris to ride in, that should be a chore!! Now I wish I had made a larger fuel cell. New wheels, redesign the twin master system so the brakes actually work, wing, So many things to do to finally finish and sort. Save some of your spare parts, I will be needing them.

Dave

 

change the intake and you'll make 400 hp easy on a fantasy dyno anyway.....sorry.

A larger plenum will raise the tuned rpm, which might add hp up top. I suspect there is a flow issue, maybe the exhaust, that made ferrari decide the tune the us 348 to a lower rpm, when on past models (QV/328) they made alterations the increased the rpm the peak power came at.

 

+1. For another 100hp you'd be looking at extensive mods (especially if your only looking at the top end of the engine).

Sonny

 

Port heads ,bigger valves , change cams , flycut pistons for larger cam grind & to accept valves(custom of course )easing valve to piston clearance & change headers ,change exhaust ,larger injectors , throttle bodies , port intake manifold ,higher volume fuel pump, adjustable regulator , flow test ,programmable PCM , dyno tune , sell your 1st born to pay for it all , OR , call NOS & get a nitrous kit for about $1000 .Blow engine & trans , spit out the axles ....etc....spend more money .......
Happy Thanksgiving Guys !
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True on every point except you missed Flycutting the expensive Custom Cosworth pistons and changing to the shim under Cosworth followers, Carrillo rods, single digit weight flywheel................ and its still got just one cam belt, go figure??!! The gearbox and axels have proven reliable.

 

I'm sure if we took a poll from owners it would not be favorable for the gearbox .Check the search for the number of it's victems . It barely holds together now , another 100+ horses will kill it quicker than it craps out now . If you look closely in the ferrari parts CD , its listed under sh@tbox .The only thing reliable on the 348 is the steering wheel . How many 348's has any one really modified enough to know if the axles / trans could take it ? A 400 hp 348 with the trans the way it is will live a shorter expensive life like the rest . Oh yeah , didnt miss fly cutting (read it again) , a piece of paper couldnt fit between the stock valves & pistons as it is .Anyway , who cares , by the time you finished the engine mods,blew the trans ,again, a 360 coupe could be in its place .Just get Nitrous ,a quick painless installation.
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You own the Flag car! You lucky guy. That is one awesome racecar. The previous owner hinted at selling it some years ago when he was selling the 358. I am glad one of the truely devoted own it. My guess is that you are spending all the shop profits on your hobbies. Good thing we got understanding wives. Honestly I think we need a 12 step program to help us control our urges. I am having this huge internal battle about my racing direction and it involves gt3 cup or pro built ZO6. I am sure you can just imagine my pain. In California we can race all year long (good weather) so I can't even mothball my urges and just think about the ski season.

Oh by the way I do have the OE seats and OE windows with all the door guts. Keep in touch!

 

And I swore I would never own one of these single belt cars..... I was punished enough when they were in warranty.

I am not sure what is going on with these gearboxes everyone speaks about. We beat the tar out of the IMSA and 358 with slicks and have yet to have even a sincro issue on either once properly set up. Time to get rid of the tennis ball sized shift knobs and start shifting with the finger tips again.

 

I agree 100% about the gearbox. Once I fixed it there have been zero problems. Even with mine the problem was not a defect but factory failure to stake a ringnut. So 100% bullit proof and I bash my box all day long on slicks too. It is so perfect it amazes me. In fact if I keep going on the 348 I have mad scientist ideas of welding the 348 differential and trying a spool.

As to the single belt I see fairly low numbers of these cars and have seen fairly low numbers of failures. The single belt does not seem to fail any more than the two belt except the single belt failure destroys all the valves. I am one of those who thinks that if I got one head off and I am doing a proper 3 angle valve job and ensuring perfect clearances for max performance I always take the other head off too anyway. Therefore single belt is not much of an issue for me. If there is any other performance difference I don't feel it. I can see however where it is a big issue in the consumer acceptable repair arena of only fixing the valves that are bad. There is a very interesting Ferrari frankenstein project going on with 400 block TR heads and 348 liners. If this project ever comes to fruition the 348 single belt problem surely could be solved but....not by me.

I expect personally zero belt issues because I change my belt yearly and do an engine out service yearly. I would like to switch over to maintenance by hours run. Do you have any guidelines on what would be acceptable running hours on Timing-belt, hours on water pump, hours on spark plugs, between oil changes etc.. for a casually clubraced car? I have just been using arbitraty acelerated maintenance schedules and probably spend too much money and resources like I always change oil after a race weekend. Maybe there is a more scientific way.

 

Wingfeather.

348's have been THE CAR TO HAVE for sometime, manual everything, no gimmicks or gizmo's and don't know if I'm right but possibly the last series production car who's intro was overseen by the great man himself?

 

I hope I'm not too off topic at the moment, but can you explain how you made your gearbox bulletproof? This sounds very interesting. If it is too off topic, perhaps a quick pm or even a new thread? Thanks,

Sonny

 

"arbitraty acelerated maintenance schedules"

Likewise, no scientific method to my madness either, overkill is cheaper that the alternative.

Street engine cam belts, I completely agree, stick to 5 yrs and they are very reliable. Failures in this time period can always be traced to a failure of another component. Not the engine to cheap out when it comes to tensioners, idlers and water pump bearings.

The Sprint engine I was building when you came by has a 4 hr lifespan on the belt before it becomes dangerously loose and falls way out of time. The cams are utterly rediculas regarding the ramp and lift (Indy car profile)and a 9500 shift point in that engine. When time permits something a bit more reasonable will be worked up.

The Enduro engine seems to be good for a season on the belt using 8500 as a shift point. I am sure it would go further but a belt is cheap and you can feel the timing fall out of spec.

Factory Water pump is going on a number of years now and shows no play in the bearing, yet I did machine an aluminum scroll impeller to lessen the cavitation.

With the Redline oil and doing some testing I am down to changing it every 3 track events but changing the filter after each event.

Sparkplugs are a bad issue at this level, and a good reason to down size the cams. I have to start the sprint engine on a hot set of plugs and get heat in it then swap to a cold set for running, PITA, just too much cam for anything but an all out race effort. I will be installing an O/S drysump tank heater so I do not have to light foot it around to get temps up. None of the above has any bearing to maintaince on a street car and is completely off topic from the OP's question. Cheap, quick bolt on HP on a car built by Ferrari? Not without giving up something else, ie: low end torque, emissions compliant, longevity. The engineers didnt leave much on the table when they built them. Gut the car and make it lighter is about the only one.

With the welded rear subframe and removeable rear crossmember, engine and trans removal is a snap and can be done in well under an hour with the axel bolts the most difficult task. No reason not to do early maintaince on a car designed like this. These folks were on the top of their game that built this one and built it with maintaince in mind.

Regarding the trans failures I read about here, I have no idea what is going on. I have seen the ring nuts loosen on street cars in the past. Locktite and new nuts is a permenent fix in my opinion. Preloads as per the manual are something often skipped and are assumed to be correct, attention to the smallest details, surface plate every mating surface of the case components.... Not an easy job to do properly but once done I have seen no problems. I usually figure on 3-4 assembly and tear downs with clearanced bearings for easy fit and removal before I have all the preloads where I want them. Three fingers on the shift knob, not designed for white knuckles and a death grip.

Dave

 

I have recently bought a 348 GTB H motor modified to challenge and its around 370bhp it goes slightly faster than a 355! Its like a missile and hits 310km/hr.
I didn't think I'd ever buy another 348 and Yellow!! But this 348 is truely amazing!
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Well this is the straw that has broken the Camel's back..finally finally finally I have realized that posting on FChat is NOT for me. This newly acquired wisdom has finally been hammered into my little brain....and I must add that it didn't arrive in an easy to swallow pill.

FChat has not only some really knowledgable,technically proficient, and skilled members which I would work beside, but some great people that I wouldn't hesitate to hang with. Sad to say, they are in the minority. There are in fact some who are idiots,jerks, and stupid child like bozo's that pop up with "clueless" branded all over their posts. WHATEVER!!!!!!!!!!!!!!!!!

So now to proceed with my last post on this forum.

Your 2 posts are NOT an accurate assesment of the 348!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

You state that modifications to the engine to achieve 100hp increase require ALL the things you've indicated and big$$$$$$$$, almost as though this is nearly impossible to do, waaaaaaaay to expensive, and requiring a doctorate in engine building. Then you go on to state your cure is a $1000 nitrous system. Give me a break. That comment is soooooo stupid when it comes to building a road/track car it belongs in another universe. In 40+ years of FIA ,IMSA, and World Cup we have never used nitrous, maybe you can teach us something?? NOT!!!!!!
We are also NOT building a Ferrari dragster or a Fast and Furious Ferrari rice racer(oxymoron????) as far as I know. This marque deserves a little more respect and is set apart by a long heritage of exotic cutting edge supercars, and world class championship race cars.

For someone who is just starting out on this site you are already up to your eyeballs in SH*t!!!!

Your assesment of the 348 gearbox has now taken you past the eyeball level.

Simply because you see some posts about gerabox failures you are now an expert!!!!!!!!!!!! FBB and I may but heads but we do it WITHOUT stupid written on our foreheads. FBB may have the cheapest fastest 348 currently tracked on a regular bassis and knows these gearboxes up close and personal. Dave Helms, well the old E.F. Hutton commercial defines how we respect his knowledge and abilites from a lifetime of service dedicated to the marque. FWIW,if there are 2 guys you don't want to match knowledge/skills with, it be them. With a little respect you might just learn a thing or two.

IF, you had been astute enough to research the 348 gearbox issues you might have picked up on a few of things:

1. Some issues were due to poor or inadequate maintenance and improper assembly. Both of which could be easily resolved during a Stooges barbecue...lol

2. Bearing failure, some of which is a result of #1. Again an easy cure that can be addressed at the barbecue.

3. The propellar shaft spline shearing at the clutch. Well, I think Ferrari has an updated shaft w/different splines. CNC lathe/mill or old school and know how
use an index collar it is a piece of cake, Or, you can send the shaft to a machine shop and they can reproduce the part at a price that is cheaper than one
puchased from Ferrari. Again, an easy job that can be performed at a Stooges beer and barbecue transmission rebuilding party.

Now you have really shown your ignorance with this statement:"how many 348's has anyone really modified enough(400hp) to know if the axles/trans could take it?"

Even though Dave Helms has mucho hands on knowledge of this he is way to polite and respectful to address your ignorance. I, on the other hand, don't give a flyin "F" about throwing a punch, in a bar, or here on FChat.

I can remeber in 93/94 Rob Dyson running a Spice chassis in the WSC powered by a Ferrari 348 engine. If my memory serves me correct this engine was even more modified than the current(94) Michelleto, and produced dang near 500hp. It used 348 gearbox/axle for testing in a 348mule before it was mated to the transaxle required for the Spice chassis. To the best of my knowlege this unmodified tranmission(only clutch/flywheel were modified) made it thru the test period with no failures.

Maybe in your future post you will stop and think that not everyone on this site is as ignorant as you.

FBB, we ran a fully locked titanium spool on the 935 Porsche. Maybe because this was a rear engine car with less than ideal suspension, but it was amazing at the improvements realized(we had initially started with limited slip) in corner exit speed, so much so that having now the ability to hook-up the abdrupt onslaught of the approx 850 trubo'd hp. we saw lap time improvements over the 5sec mark. Must admit with the full lock set-up we had to completely redesign the half shafts.
Using either aluminum or titanium spool there is a significant weight reduction by race car standards. Don't know the feasibility or cost, but you may want to look at the Weismann Locker as an alternative. Best of luck.


Hope everyone had a happy Thanksgiving....as for me??? Well, I'm outa here. Take care

 

Man.......you must have bought a really crappy 348.

 

So did I miss the number of the H manifold size difference? Makes no dif, goth and I are already doing one. Oops, sorry, um, ignore that last statement...

 

Bruce,

You and I rarely agree on recipes but we often agree on ingredients because our compromises are very different as well as our backrounds. Sparring with you is fun. You can't let the "blown alternators" (redzone) and "dropped valves" (Ernie) get you down and give up racing. I know these guys and they mean well and I guarantee if you met them in the flesh you would find them good enough to share beers with. Hopefully after a little break you will return with renewed interest.


Regards,

FBB
One of your biggest sparring partners