348 Performance upgrades to get to 360hp

Ok folks after thinking long and hard over the past year here and contemplating a multitude of different ways to make horsepower with the old 348 I have decided against any forced induction just because I love the sound of the engine to much and if I really wanted to blown car I would throw the Vortec I have been staring at in my garage on my TransAm.

That being said I have come on here to basically be torn apart by the best technical minds in the business (or in their own minds) before actually starting my project. My goal right now is starting from my base 348TS (with Motronic 2.7, PowerChip ECU’s, K&N Filter, No cats and a Tubi which at the last dyno pull I did a while back netted 283rwhp@7500 RPM’s and 193 lb-ft@3900 RPM’s assuming 18% loss in the drive train that gives me in the 330hp range) to get to around 104-106 hp per liter on the car or the 350hp to 360hp range at the flywheel.

Now to get there I need approximately 10% more horsepower than what I have at the moment but heck I think I could always be forced to stomach a little more!  Now for my question to you what do you think it will take to get to that goal on top of what I have done currently?

Here is a list of problems and ways I have found to possibly address them that I am interested in your opinion on.

1. At the moment I am having my throttle bodies ported by Kermit at Durable1 to let the car breath a little better. I am not sure on the final measurements but I starting from a base of 55mm I believe that we should be able to increase it to at least 59-60mm increasing the flow by a minimum of 15% into the plenum. However my first problem presents itself here. The stock airbox and intake track I don’t think can keep the engine from gulping for air given the stock throttle bodies and now the larger ones. Here are some measurements I took off of them tonight multiple by two as the car has two separte throttle bodies:
a. Airbox Inlet 77mm
b. Airbox Outlet 63mm
c. MAF inlet/outlet 63mm
d. Intake tubes from MAF to TB 55mm
Now from my calculations this might be just enough to flow the expanded TB’s but I am not sure considering the disruptions from bends, the air filter and other areas as well as the Intake tube from the MAF to the TB. What do you all think? I have been toying with the idea of getting a set of filters from BMC http://www.bmcairfilters.com which I have heard have been used in a few of the Koenig cars as well as other modified 348’s. Any thoughts on them and their performance benefit? I am thinking the increased flow might be worth it as they have an 85mm inlet and outlet to feed the MAF’s and tube to the intake as well as a much straighter shot for what I would hope to be good flow but still leaving me the MAF and tube to the TB’s as the bottleneck. Anyone know of any cross reference part to the Bosch MAF part number 0 280 212 018 that is larger but support the same connectors?
2. Considering I am trying to feed the car a lot more air I need to get some better flow though the engine as well. I considered deeply porting the heads but after reading the porting a polishing threads as well as talking to a man who has been there done that and only achieved 9 hp max difference in the head after extensive work I have decided to avoid it. The intake manifold and cylinder head meet up smoothly and I have no reason to port match those to areas as there is very little deflection there at the moment as well. So I have turned my focus on the cams. I know that the exhaust cam timing on the US version of the car is significantly different from that of the European model car.
a. European cars
i. Intake Opens 14 degrees before TDC and closes 53 degrees after BDC.
ii. Exhaust Opens 53 degrees after BDC and closes 10 degrees after TDC.
b. US cars
i. Intake Opens 12 degrees before TDC and closes 56 degrees after BDC.
ii. Exhaust Opens 54 degrees after BDC and closes 12 degrees after TDC.
Now has anybody been able to quantify the difference in the power outputs of these two different timing specs? I would think that the European timing would give me a little bit more power but is it enough to reach my goal combined with the other additions I am not sure.
The next step here is to upgrade to another set of cams. I have talked to Walter Koenig and he is telling me that with his cams he expects at least a 40hp gain based on their dyno testing but are going to run at least 5,500 Euros and with the crappy exchange rate will cost me more. Does anyone else out there know where to get a nice new set of cams ground for the 348 or for that fact does anyone have the cam profile to bump up the power around the Koenig numbers? Any idea on a spring upgrade or ability to cross reference to support the new cams?

3. Next on my list after the above or actually while doing the above I am looking for input on a set of pistons. I am more than likely going to get a set of 11:1’s from Norwood along with a lighter set of con-rods just to reduce the rotational mass on the crank and have the engine spin up even faster. Anyone see any issues with the engine being able to handle an 11:1 compression ratio or the ECU’s ability to keep up?

4. Finally on the exhaust path right now the engine is breathing pretty damn well but I suspect from looking at pictures I have of the headers when I had them off two years back I think they can be improved as a last resort. Maybe with a set of Tubi headers or just improving and smooth the collectors, and coating them. Any thoughts?

Thanks for any help you guys can give me. When it comes to a small block chevy I know my way around but this is a different ball game and I want to get cut down to size before starting. Now I know some people out there will just say buy a 355. Well that thought has crossed my mind but to me the 348 is a better car IMHO and looks better in my eyes so I don’t want to get rid of it for the life of me.

I (and probably) the other 348 owners on this board look forward to the discussion in this thread.

 

I am sorry that I am at work and cannot respond to everything at the moment but I will get back to peoples questions later tonight. As far as the driver is concerned I have spent a good deal of time on the track and will have Panoz and Skip under my belt by the time I finish this little project in the middle of next winter.

My main goal out of all this is just a little extra umph without changing the characteristics of the car completely (thus my no turbo or supercharger decision) as well as the simple fact that I just like to tinker and have done a good deal of build ups on SB Chevy's over the years and have been dying to crack into something on the 348 ever since I got it a little less than 4 years ago now. Tinkering is fun buts its a lot more fun when you have a plan and can avoid cost overruns because of it.

 

Just to answer everything in order here I will reply in order.

Chenshan - With regards to the PowerChip ECU's I posted the pre and post dyno results some where on the old Ferrarichat web site right after I got them doing two pulls with the old ECU's, taking those out and installing the PowerChips driving around 20 minutes and then doing two more pulls. Bottom line is the quoted performance gain from them was off but there still was a substantial gain in average hp difference thoughout the RPM range. However lately (before I disassembled some of the engine) I have been trying to figure out why the car has started running rich at idle up to 2200 RPM's.

Bottom line the hp gain quoted is off for their 93 octane chip but there still was a gain. The cost of the chip was $900 for the set of two I believe as it was a few years ago now.

Install is sort of a pain as you have to crack the ECUs open after removing them from behind the seats. Not hard if you are use to working with computer hardware as I am but I can imagine could be scary to the novice.

 

I looked into this and as much as it would be a cool little plan the costs are to prohibitive and I would be up in the used 550 range all said and done after machining, testing, and tuning. I like the 348 a lot but right now I am looking at a max of 15k for parts that I am willing to spend as I dont want to cut to much into the 550 or 512TR saving plan.

John

 

First off BillyBob let me say I am sorry for never getting back to you and working on the suspension when I had mine apart. I got side tracked with work for a LONG period of time then and just ended up bolting everything back together. Talk about a pain in the butt.

348 Turbo man you have been trying to sell me on the Norwood upgrade for a year now. I got to give it to ya you have me thinking about it to no end and I have talked in depth with the folks at Norwood about it and heavily considered it but for the same reason I wont do an engine swap I want to put a max of 15k into the car. Basically broken down the Turbo kit was 8k twin turbo 7psi and Motec 9k that was not including the engine rebuild.

Now getting into the meat of the conversation.

[BillyBob]
I don't think so on your HP. You are way off. IMO there are dyno differences that are calculated for ambient tmep and sea level during dyno puls etc.. Your driveline loss in closer to 15% and that would put you are 325hp at the crank very close to advertised HP figures of a stock 348 with later ecus and later single can street challenge exhaust. Many people think the power chip works and kn etc.. but in reality there is not much to be gained in the ferrari world there due to no testing. The SB chevy world is differnt. Everythjing is tested and others retest them and debunk myths like whose headers make the most power etc...
[/BillyBob]

I assumed 18% loss as that is what both Koenig and Norwood had told me to expect as a difference but it sure as hell hasnt been tested. I dont mind assuming 15% as I do feel the engine can be between 325hp-330hp given the upgrades I have done. My g-tech amazingly was also fairly close rating the car at 289 in second gear this summer.

[billybob]
90% chance you will get no improvement. The better bet is to spend 8k and go to a motec system with MAP. MAF's are notoriouslly impossible to get better flow excpet again in the over tested world of mustangs, F-bodies and Vettes. but even then claims are high reality is low.
[/billybob]

You could damn well be right here as I am not going into this with the expectations I get reading my latest Summit magazine for TB oversizing. My experience with MAF's hasnt been that bad but I have broken more than my fair share by being stupid so am looking to find a part cross reference that matches up with a car others are tuning. No use repeating work. The Motec makes a hell of a lot of sense and I am still considering it fully but I am not sure if the bang for the buck is there unless I would go to a turbo system as 348_Turbo points out.

Since the TB's are now larger I am trying to figure out how to ram more air into them and the best setup I can find is the BMC one at http://www.bmcairfilters.com (go to the site and find the setup for the 348 and take a look at her) as its directly connected to the intake tubes from the side of the car and flows each bank separately into the MAF's and TB with a minimum diameter of 85mm till I hit the MAF's. However given my limited knowledge of fluid dynamics I believe that there would still be a benefit because I would ensure that the intake chamber is as full of air as possible. Please check it out and let me know what you think.

[billybob]
Yes and you need a proper ECU like the motec to tune it or need to break into the bosch and be able to reflash a eprom to your new specs. Vettes no problem bosch motronics...if you find someone let me know!!!!!!
[/billybob]

Working at IBM has its benefits while I am a software geek I have a lot of hardware geek friends and we are going to see if we can come up with something to burn in our own programs with repetitive testing on the dyno, etc.

[billybob]
Pitiful differences in HP. Overlaps can be experimented with but what a pain. This is no SB chevy you have to drop the motor to re pin the cams to change overlap and get your degree wheel on etc.. what a pain!!! Every change will take 20 hours.
[/billybob]

I know this is a pain but I have gotten fairly smooth at dropping the engine and can have it out in a little over an hour now. Degreeing in the cam is going to be the pain in the ass. This is the reason I was looking to see if anyone on this site knows of an exact difference in the hp output of the european vs. usa setup. I was thinking maybe an old challenge setup crewman or just some shade tree would know the difference as I have heard this was a common tweak in the challenge cars. I once heard a from a factory worker as well that the euro cars put out around 320hp in the 1990 model year versus the 300 the N.A. cars got because of this difference in cam timing. Seems hard as hell for me to believe it as I cant believe that small of a change in overlap would make that much of a difference. But an interesting thing to look at if true.

[billybob]
You have to reweld your sticks and recut. Not enough metal on the base circles. alter lift /duration etc. and change loads on springs and valves. Who does the engineering on this stuff? NOBODY. How about SB chevy? Everybody. Infact with SB chevy we can even buy shims to shim the springs to get even spring pressures over the entire valve trains. Do you know about doing that, measuring spring retainer installed heights etc.?? You can't get than in a Ferrari unless you custom that stuff.
...
Yeah all talk! What other engine mods? REemmber that 9hp you talked about. Well getting a 3% increase in HP = 9-10hp. 3% from cams, 3% from pistons, 3% from flow, 3%..... they all add up to big HP. This is what race engines do. Race engine builders don't get 20% from a cam they get 3%, 5% etc.. It is all part of a package and to get more than the 3% from your cams 10hp not 40hp you have to do all the other stuff and maybe you'l' get a few more HP. Unless you are in the F1 big bucks you are going to get the solid gold magic 80hp cam. You are going to get paco who can't speak english and had a fight with his wife grinding your cam then throwing it in a cardboard box to be dinged around by FEDEX and you just hope it's right.
[/billybob]

This is what worries me but I think I will just get a blank from Norwood and have someone carve it out for me. The hard part is finding the correct profile. I have had pretty damn good luck getting 348 Turbos friends to deliver on cams they ground for my SB's, but you do have a point this is one cam versus four. The spring issue I believe is going to be a pain in the ass and I would not like to have to go over board here with retainers, etc but if I go to crazy on the cam I know I would have to upgrade here as well.

Koenig's statement came with a pretty confident sound but when I pushed them on dyno numbers they didnt have any so once agains its basically going to be pay 8k install and more than likely get 8-12 which I believe from a set of cams instead of 40. His 40hp quote was in combination with a reflashed 2.7 ECU and exhaust. I think that it would be possible to get the same performance out of the PowerChips, and my exhaust and intake if the sensors can handle the extra air, etc. You thoughts?

Of course your final statement rang home loud and clear and I have been doing that slowly but surely for the past month here. I have had the seats swapped out a long time ago saving probably the most weight. Removed the sound dampening crap under the carpet, trunk lining, stero crap, got my fat butt to drop 35 pounds etc. All in all shes down 185 pounds on the local scale here from where she was 2 years back. Did you trim anything else? I dont really want to make the car totally track oriented so interior parts remain.

Also out of the 15k I am putting at least 3k of that into suspension as I really want to get back to finishing the work I started last winter over the spring this year.

Anyway I look foward to more discussion as this is the best thing for me right now and I welcome the critizism as it makes my final plan stronger. I believe that the engine is capable of the 104-106 range and still remaining driveable.

At the current moment my breakdown of work in my project plan is:
This spring...
intake from BMC: 500
fabricating rest of intake: 100 in material and my time
suspension: poly or delrin bushings, revalve shocks, springs 3000

This summer/fall...
pistons 1850
rods 2000
misc gaskets 500
cams 5000-6000

Now if I could get a relaible turbo kit for the 8k above that would work with the 2.7 unit and produce a reliable 360-370 with a intercooler I might have to look into that again (at the same time it would not be as fun and challenging as getting there in the na fashion), but from my understanding there is no way the stock engine will hold up to even that low level of boost (7psi) but then again maybe Norwood can pull of some sort of magic.

Comments?

 

Billy Bob - Of course I know your an a**! I would rather have a bunch of a**es make me think about things before I hop on the bandwagon buying crap than every one just nod in agreement.

I am not quite sure the performance gains on the LS6's are quite as bad as you would expect with out the upgrade EFI. I know a couple of guys that can squeeze out an extra 40 rwhp on the dyno with some porting of the intake manifold, a larger TB, and a good set of headers. The LS6 is a great engine but still hampered at breathing.

The only reason porting and polishing is still in my head is that the last SB i built I used a sweet pair of Trick Flow TW heads and just bolting them on gave me a 64hp gain from the improved breathing over my old Edelbrock heads. I know I know the SB is a different engine but it just seems there might be something there.

But then to think of it the cam I added after that 240/[email protected] made another 35hp difference at 6250. (side note: When I look back at my old post I actually misquoted the cam timing it should be before BDC on the exhaust cam not after BDC. I also believe I am wrong that the duration I quoted is not at 0.050 and instead is advertised duration..I wish someone could tell me!) Assuing the above the stock cams already are 248/244 which is a pretty tame profile compared to most of the Supra's (262 is considered mild) and Miata's (272 is mid range) I have seen out there. Obviously there is lift having to be factored in here but seems like there is something to be gained in this area. The only car I could find with the same duration in a DOHC setup was a 1.6L 1989 Acura. There has got to be some hidden power in there. Now I just need to find someone with a profile they know to work!


From my reading here the past few days the 2.7 unit should be able to handle the extra air I get into the system if I stay without forced induction. BUT I am a little worried at the flow rate of the stock injectors. I havent found any documentation that states what the stock units flow at. I was thinking of replacing them with some larger injectors with better atomization than the old Bosch units as I dont think Bosch switched to their new pintle and seat design until the late 90's but you can get replacements that have them in earlier casings.

Kenyon I would really like to know if you can give me more information on the reason behind yourself running a new fuel pressure regulator. I am not sure if the fuel system if going to keep up and seems you might know something I dont.

And here is a plead for everyone PLEASE PLEASE let me know a cam profile that works on the 348!

 

It also appears that Michelotto was able to get 450hp out of the engine in their most extreme form but had multiple between 380-410. http://www.qv500.com/ferrari348p8.htm I wish I knew what they did to the engine in total as it would be interesting to see what all went into the power gain.

 

Cool project but doesnt work for me and my track car. I think there might be enough interest though to get some cash amongst everyone to do the research.

John