how much boost can the 3.3 handle?

[dynevahn]

Im curious to see how much boost the 3.3 can handle. I have done every mod I can think of to this car but would like a little more push. Currently Im running 1.1 bar on 114+ octane with alcohol injection kit (50/50 mix) and andial enrichment system. I see the boost gauge goes all the 2.0 bar. has anyone ever seen that? I wonder what my limits would be on a 3.3 with 15k miles and sc cams?

[Bruce M.]

What are your afr's at full boost?

And, no offense meant, but the mods you list are just scratching the surface of available mods to that engine. Do the right ones the right way, and you can get 600+ hp to the flywheel at no more than 1 bar or so, and you won't need any more boost to get that "push" you're looking for....

[dynevahn]

full list of mods, k27 highflow s turbo, fabspeed zork tube muffler and headers, kokeln intercooler, sc cams, alcohol injection kit, fabspeed air intake, msd igntion, advanced timing, 114 octane, and 1.1 bar spring. Supposedly the engine was done by andial years ago but I cant confirm that. What else is there to do besides the twin plug and efi?

[WydRyd]

EFI will open up a whole new world of HP and throttle response. Listen to Bruce.M, he knows his ***** when it comes to these engines.

You're still running the mechanical CIS injection, right?

P!ss it all off and go EFI if you want to see big HP numbers.

Juan Ruiz from this board ran up to 2bar with his 3.3 Turbo Carrera on race gas I believe, however, that was with aftermarket EFI. You'll never see those boost levels with CIS.

[Bruce M.]

I don't know about listening to me, but you can listen to a bunch of Porsche tuners who do these cars in their sleep by now--Bob Holcombe, Jerry Woods, Imagine Auto, Protomotive, etc., etc.

EFI and twin plug can add 200 + reliable horsepower to your set-up. At that level, I'd ditch the Sc cams, though (use maybe some GT2 Evos), and the turbo would be different, and you'd want different rods and rod bolts, maybe some slightly bigger Mahles, maybe a 964 or 993 crank, some titanium retainers, valve springs, need to ring the heads....

Here's my build sheet. It is by no means the most radical 930 engine hop-up out there, but it is representative:

Engine: 993 crank, 98 mm 7.5/1 Mahle Sport pistons (displacement now 3.45 liters); Carrillo rods and bolts, titanium retainers, competition valve springs; twin-plugged head, Niresist rings, Raceware head studs; Carrera manifold, AirResearch TS04 turbo; Siemens 72 lb/hr injectors; factory GT2 EVO cams; stainless steel, hand-fabbed exhaust (headers and muffler) with built-in twin HKS wastgates, 1100 cubic inch intercooler; Motec 48 Pro engine management, programmed on engine dyno, cockpit boost control with 5 settings--.8, .9, 1.0, 1.1 and 1.2 bar. Dyno figures: 512 hp at the wheels at 1.0 bar. Other: Big Reds up front, G50 hydraulic 5-speed conversion with Guard limited slip diff, WEVO G50 shifter, 935 clutch, Fikse FM-10s, 8s in front and 11s in back (running 315/35ZR17 Michelin Pilot Sports); front strut bar, 23mm torsion bar up front, 30mm in back with 200 lb progressive helper springs, custom valved Bilsteins all around, Charley bars front and rear; Ruf front spoiler with fogs, factory boxed rockers, Champion momo wheel, gauges reconditioned by North Hollywood, 935 boost gauge in place of clock. All engine work, and exhaust, performed by Bob Holcombe of Motorsport Design in Scottsdale. Additional Motec tuning by Chris' German Auto in Seattle.

Sunroof coupe, black leather interior; special ordered from the factory in 1978 by Ted Williams and his son.

Like I said, there is virtually no limit....

[KillerDynoSoar]

Can we see some pics of these cars dynevahn and Bruce?

[DRV2FST]

Also, the 3.2 intake is rumored to yield a big gain. As well as more free flowing heads.

[Bruce M.]

Yup. That's wht I mean by "Carrera manifold" in my build sheet.

[DRV2FST]

Sorry for the redundant info.

[dynevahn]

bruce thats a nice setup you have there. Just when I thought I was at the end of the road I see the possibilities are endless. The carrera manifold, what kind of power comes from that and what modifications if any would I need to do in order to have that work?

[Bruce M.]

Dynevahn--

You know, I don't really know the answer to that, because every 3.2 manifold install I know about, including mine, has so much other stuff that happens at the same time (like efi, bigger intercooler, often some engine work), that it's hard to say how much the manifold does, by itself, or whether that even makes any sense.

I know there are kits out there that use the 930 manifold but convert to efi (Pat Williams' set-up, I believe, for one), although I don't know what kind of power they make.

Basically, though, the carrera manifold, twin plugging and efi are going to give you big gains in driveability, power, reliability, even gas mileage (if you stay out of boost-ha). That's IF the install is done by a tuner who knows how to tune the system you use.

The good thing about these upgrades is that they leave you with solid power while staying within reasonable boost levels, so your engine can actually last. You can make enough power and torque that you become traction limited, and not power limited, at 1 bar.

[Miguel Antonett]

Impressive description of a wild ride. Now need some pictures to see how they look.
Thanks!

[Bruce M.]

I'm not much of a pictures guy, but these requests have inspired me to snap a few here. Then, I'll have to learn how to post them, so bear with me...

[VZ935]

I agree with everyone else that if you want to get more power you need EFI. My engine sounds like it is very similiar to Bruce's . It was built by Rob King at SCARGO Racing and the M48 was set up by Rich Walton and Jerry Woods . On Woods' dyno the motor made over 600hp and 550 ft lbs of torque at 1 bar through mufflers with tiny turbos....ironically we never ran it without mufflers but wanted them for Laguna Seca days when we had to make sound. This motor , I think , has a track record at Road America in GT1 of 2:16 ... even geared way to tall for the track pulling a 190 mph top gear in a 4 speed. So it makes some great power and is dependable..never a DNF

[VZ935]

[Bruce M.]

Sweet. What wheels and tires are you running there?

[dynevahn]

bruce so your saying the k27 highflow s from imagineauto isn't the best turbo?

[DRV2FST]

VZ935 Please show us full 360 photos of that car.

[Bruce M.]

Ask Stephen. I trust him. I think, from what I know of Kevin's Hyflows, which as I understand it are reworked KKKs, that IF you did the efi mod and other associated changes, and you stayed with KKK, that you'd want the HF 2, not the HF.

I think I might try one of those, with the zero clearance treatment, for my next turbo.

Except I just thought that I probably don't have the right flange for that style. Oh well...

[VZ935]

Bruce ,
The wheels are from Jim Fikse and I am running 14x18 in the rear with 14 1/2 Goodyears and 12X18 in front with 12 1/2 inch GY Slicks . But when we built my friends GT1R car we tested tire and wheel combinations and actally a narrower tire works better and he went to the 13" yoks in the rear. My turbos were built by Greg at Tial Industries






http://img.photobucket.com/albums/v600/ChevyThunder/GT1%20R/442D1715.jpg