Imo000

Doesn’t that pretty much explains why the boost was limited to 11psi?

Vast majority of turbo cars on the market also run stock around 10-12psi, so the 951’s stock setting of 11 falls right in with the rest.

lart951

That 930 of yours most be crazy to control, it will indeed require more of the driver than a 951 similar power.

The following things have been removed from my car:

I removed the buckets lights and assembly including the motor, switch to euro lights.
A/C deleted kit
Removed the cruise control motor
Removed rear matt and sound deaf. material
No spare tire or tools
Rear seat was deleted
Rear hatch release motor
Rear hatch wiper and assembly
Removed Cat converter
Running SFR x-over pipe & down pipe
and some other stuff that I don't remember.

lart951

The Evo VIII runs 19psi from factory.

hacker-pschorr

This thread needs more cowbell.

GlenL

Explore the space, baby!

(Not nice making me laugh. My co-workers give me enough odd looks as it is.)

tedesco

Could not be online during the last days. Just a few things to clearify: As i tried to point out I very much like the 928 too and certainly would NOT like to almost intentionaly destroy an engine. I also did not proceed like this on the 951s i own. A build should be seroiuse and not just like "lets see when it blows". I was thinking of modififying a 928 when I had a look at this forum. I at least stepped through the last 10 pages of search results with some keywords like "turbo", "supercharger"...
What I found was that quite a few people spend massive money for their modifications and came up with only dissapointing number for my taste. OK. you can say 500HP is a lot of power for a car of any standarts but 500HP from an 5.7L engine is not an achivement especially when turbocharged or supercharged in my eyes. There are plenty of pushrod engines around that arrive at these number and are perfectly relyable too and they are NA engines!!!!
So what´s all the deal with compressors, turbos and so on if you struggle making just 100HP/L? If would have done this I would call this dissapointing. I am certainly uninformed when it comes to 928s so please correct me if I am wrong and what are the specific problems. I tried to find out more by doing some posts but the feedback was very little which confirms me in my thinking that 928 owners might just like their cas as they are rather in modifying them.
Where I live 928s are as expensive as 951s or you can say 951s are as expensive as 928s depending on your taste, so the arguments about tossing a cheap 951 engine instead of wasing a 928 does not count for me.

heinrich

That is very very impressive. I doubt it's really a drivable street car anymore, but a missile it is! Will you post pics, also of the interior please?

heinrich

Look at that bunny Dude ... see the suspension squat? Time for some Jenny Craig action ... a la LART951.

Imo000

Luis, again read carefully my post. The second sentence starts with ”VAST MAJORITY”. In Canadian it means “not everyone”, I think it means the same in Californian too?!?!?!?!

sweanders

My 951 Cup weighs less than that with a full cage (and full interior), only thing that makes it not perfect on the street is the amount of power under boost since it is hard not to goose it as soon as there is a gap in traffic. I should be at similar power as Lart after the turbo swap with a more usable power curve than with the stock turbo which gives the 951 a torque curve similar to a turbo diesel engine (355 ft.lbs at 3600 rpm).

Imo000

Well its’ rather simple. 928 were all N/A and because of this, it takes a lot more effort to boost it let alone run high PSIs through them. Unlike all the other turbo Porches, the 928 doesn’t have forged pistons, adequate crank venting system for boost or positive pressure sensitive ignition & fuel control system. If you would take a regular 944 and try to boost it, you’ll come up with the exact same problems but with only half the HP.

cobalt

How are you guys getting your cars down in weight so much?

My 89 S2 has Recaro speed seats rear seat removed with bolt in roll bar. Factory rear wiper delete. Air bag delete. I also have the SFR exhaust, cat delete. I have also removed the spare tire, jack, tools carpet etc. I am running D90's which weigh nothing compared to most wheels and I am at 2959 pounds. I still have factory lights and A/C, a/c is going this winter. Do these 2 items amount to 200+ pounds of weight savings? IIRC the 951 starts off slightly heavier than an S2 to begin with so I think I am missing something somewhere.

What turbo are you guys using? Is it on par with a K29? I found the K27's loose wind in the higher RPM range and I would assume with the pressures you are talking these would not work. How does the lag compare to that of the earlier 930's?

sweanders

My car is bone stock when it comes to weight reduction items except for having a steel cage instead of the stock aluminum cage. It weighs 1240 kg's with half a tank and no driver. Don't have spare wheel or tools in the car. The cup cars (like mine, Lart has a standard 951) have no inner fenders, no cruise control, no AC, no power anything, no stereo and no sunroof which helps the weight stay low. It has a complete interior with a Recaro bucket + manual passenger seat and still has all the sound insulation in place. It is not a light car compared to other 2 door 1980 coupes IMHO but just like the 928 it is a sturdy body but not as tank like as the 928 (not meant in a negative way). If I wanted to make it lighter it would be fairly easy to replace the front fenders and hood with glass fibre items and the hatch with lexan instead of the heavy glass. If it was a dedicated track car I'd move to gf doors and lexan glass except for the windscreen and gut it. To go more extreme it is possible to cut of the spare wheel well and go to gf fenders in the rear as well. I already run light weight Fuchs wheels (16x8" and 16x9") but I guess that there are lighter wheels out there. The Cup cars have magnesium intakes (just like the 928) and magnesium oil pans. Also the alternator on the Cup cars is a lighter one than stock 951's.

I did not dyno my car but dynoed an identical car with chips, boost controller and FPR from mine and it had 279 hp and 480 NM. I ran slightly more boost than him but the combination of stock wastegate (shimmed) and stock turbo kills boost at RPM's over 5000. We both had 1 Bar at 2900 rpm's with the stock turbo. My car is almost ready to roll with a Vitesse stage 3 kit plus TiAl WG and an EBC and others have reported 310-330 rwhp at 1 Bar with similar setups. My goal is to have over 400 rwhp at higher boost and will tune after detonation, EGT and A/F ratio. With different cam, head (still 2v) and headers and tons of tuning and little stuff (already have a 3" exhaust) I'd be aiming at 450+ rwhp. Special Tool on the 951 board has hit 533 rwhp on the stock engine except for headwork and headers with the same turbo as mine and has put down over 540 rwhp with some modifications to the turbo. He is running higher octane gas than I can easily get ahold of. This is all still on a 2.5 litre 8 valve engine, there are some 3+ liter 951's using 16 valve heads and that would be interesting to push the boundaries with..

I hope that someone will build a low compression turbo 928 soon to see what it can do.

H2

Anders,

What happened to your 928?

Harvey

sweanders

Sold it in a weak moment.

But the 951 is better for my type of use, lighter cars are cheaper to track and the Cup car is better suited for track driving than a fully loaded 928GT (IMHO).