Post 3.2 rebuild - What would you do?

[asphaltgambler]

Your are knocking on the 300HP (at the flywheel) door!! Very impressive cosidering very little other mods and stock Carrera intake and T-body.

[camgrinder]

Richard those are great numbers.

Ive heard that style dyno can be 10% lower than a dynojet

[Shuie]

congrats! Thats awesome.

[911-32]

Originally posted by KobaltBlau
so, 911-32, do I understand this right: the big cams push the retainers into the stem seals and muck them up?

Also, I assume you are still using the RoW stock 10.3:1 pistons. did these pistons require any machining to clear the 3.8 supercup cams?

I also assume you are using the stock carrera 3.2 intake. does the engine stumble at all at lower rpm part-throttle conditions?

Also, is that dyno chart rear wheel horsepower?

I was told it was the retainer and the guide that were pinching the seal, but not being a mechanic, I don't really know what it all looks like or how to describe it any better. I believe the fix was to machine a little off the valve guides.

I am using the std RoW 10.3.1 pistons and no machining was requiring. Camgrinder in one email told me he has done even more extreme cams for use with these pistons without machining. I am using the std 3.2 intake and throttle body. I have not spent a penny on these as one day I would like to go the ITB route. I am fairly confidant that extrude honing and MAF could give a few more hp. The engine stumbles at idle and very occasionally stalls as you dip the clutch before coming to a stop. Once off idle its almost as civilised as before. With the SSIs and an open stainless muffler it sounds like a big V6 2 stroke outboard boat motor at idle - very lumpy and cammy sounding.

Unfortunately, I am not getting 300hp at the flywheel. The Dyno Dynamics dyno computes fwhp. Using info from engine dynos and actual tests on various gearboxes and drivetrains it calculates all the drivetrain losses. I believe this is only the second installation in the world and it is being used by various high level race teams such as Subaru WRC among others. The results on the 911s that I have seen tested are all intuitively right and we have now done a lot of 3.2s on this dyno. The vast majority of euro/RoW 3.2s make 220-230fwhp (vs 231fwhp claimed ex factory). One chipped and exhaust modded 3.2 made 240fwhp and a Steve Wong chipped CS made 236fwhp. One MAF and SSI 3.2 made 248fwhp.

EVO magazine are now using this dyno to test all their test cars. When I was there, they were running up a BMW 130i and a new Golf R32.

As John says, Dyno Dynamics tend to read lower than Dynojets. The owner of Weltmeister believes he is seeing about 5% less fwhp than that extrapolated from Dynojets in the UK. If so, then I am seeing *perhaps* an extrapolated 270+ dynojet fwhp - which given the hp of the recent 3.4s and 3.5s on this board, sounds not too far fetched. Regardless, of the absolute numbers, I know I have gone from 225fwhp to 260fwhp and that the character of the engine is quite different. More cammy and free revving with a higher power band and good strong power from about 5000rpm to redline at 6850rpm. It is much more like a 2.7RS engine in character but with more torque and that is what I wanted. Its another way to get the 250+fwhp of a 3.6 conversion but I wanted to keep my known, low mileage engine rather than transplant. I don't claim its better - just different (and I suspect cheaper). I like it anyway

Although this is an engine building forum, I thought I would post a photo.

Cheers,
Richard

[Steve W]

Richard, your dyno numbers are fantastic. When analyzing and tuning several Euro 3.2s from this particular dyno, it appears that the max practical output from a optimally chipped stock 3.2 for this dyno is approximately 240 fwhp with 98 RON, and that would be Steve Darnell's 88 Euro Clubsport. Ian Highfield's stock 86 Euro, which started at 239 may dyno 245-247 after chipping, we'll see when the numbers come in. Those super sport cams sure look like they wake up the top end. I saw your afr numbers on the Porsche Club GB site and you should gain about 5-8 hp at the top with some top end fuel adjustments. That would put you at 265-268 hp - not shabby at all. The occasional idle stumbles and stalls have to do with the lift and overlap of the camshafts. There is a fine line of adjustment of the idle mixture and idle speed to get it to stabilize. Did you perform this dyno run with the my chip still in the DME?

[911-32]

Hi Steve,

Yes, your chip was in the car for the dyno run. I will be in touch re the new chip we discussed in the next few days.

Cheers,
Richard