924Board.org

[Raceboy]

I am considering changing the compressor to something more capable as the turbine is adequate but compressor wheel is at its limit.

I'll drive it for a while and in winter decide what to do. Good thing is the turbo is standard T3 flange and downpipe is V-band so changing the turbo is not a big ordeal.
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'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[DutchPug]

Nice results Peep. Recon you have the low 931 cr ratio? And normal fuel? Then the results are particularly nice.

[Raceboy]

Compression ratio is 8.8:1 and yes, regular 98 fuel. Ignition advance is 22-24 degrees at full boost and few degrees more on hot day I get to the detonation area so not much room with pump fuel at that boost.
_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[Cedric]

So 220Hp at the wheels, nice results, guess 250 a the wheels should be possible with more conservative timing and more boost (bigger compressor)

If you ever want more
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1980 924 Turbo
www.instagram.com/garagecedric/

[Raceboy]

Taking the lowest wkW value (167 rwkW) makes it 227 rwhp (hp = kW x 1.36). Highest measured value was 172 rwkW

But I will drive this turbo for a while and have some track time (which is very low for now unfortunately), then decide.

Car is quite fast for track even with this combo, easiest way to gain power is to go E85. I will decide during winter.
_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[Cedric]

oops, misstyped, yeah around 230 at the rears. What tyre dimension do you use, should need quite some rubber to keep down to the tarmac at the circuit. Hope we can get some incar from the track, in the real world at the track, 200 or 250 rwhp often isnt the deciding factor for speed, more seat time and practice is

How available is E85 over there? If you cant find it close to the tracks its quite annoying, especially since the consumption with E85 will be much higher ..
_________________
1980 924 Turbo
www.instagram.com/garagecedric/

[Raceboy]

Unfortunately Statoil quit selling readymade E85 2 years ago because the government did not had a suitable tax ease for it that was mandated by EU. In near future a fine is due most likely for that from EU...

But I can get a denaturated ethanol for 1€/l anytime and mix my own E85 with it.
We have done this quite lot (have alcohol percenatge gauge also), last time bought a 200l barrel for my friends drift BMW e36 with S50B32 turbo engine. With 9.5 CR, HX40 Super and 1 bar boost it made easy 740 hp/880 Nm. Scary with 1100kg car

I have almost new Toyo R888 225/50 R16, those are ok for track. Not ready to drive with race slicks yet, I'm too slow for them...
_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[Raceboy]

Since the weather was perfect on Saturday (sunny and 14C) I went to check the performance of Gulf with RaceLogic Driftbox despite a slight hangover. Results were quite good, I think air was cool enough for turbocharger (which makes it even more clear that compressor is at the edge of its efficiency, otherwise it would not matter that much) as the car ran faster than before.
Too bad the tarmac was also cold which meant that grip was not the best.

Results:
0-60 km/h 3.0 s
0-100 km/h 5.1 s
400m time 12.9 s
400m speed 181 km/h
_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[DutchPug]

Wow very nice results for 224 whp. Either the car is very light or you have a bit more power.

What is the cars weight?

Want to get a Racelogic box too although i have a Gtech competition pro, think the Racelogic is a better device.

Have not tested my car with my Gtech yet, but doubt it will do a 12 second with the full interiour etc.

[morghen]

well 181km/h
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https://www.the924.com

[Raceboy]

It's actually more closer to 230 whp but according to datalog the injector duty cycle was ~77-78% (630cc Siemens Deka's) so it seems the car made a bit more than that thanks to cool air. Which directly points out that the compressor is on the efficiency limit, otherwise it would not matter that much.

When I went to scales two years ago car weighed 1091 kg with me (92 kg) half tank of fuel, 17" Cup 1 wheels and heavy battery. Now it has lightweight battery (-14 kg) and BBS RS wheels (-4 kg from each wheel, total -16 kg), but glass rear hatch so the net effect is pretty much the same: around 990 kg.

EDIT: Is the Competition Pro even GPS based or just accelerometer?
Racelogic Driftbox/Performance Boxes (difference is just that the driftbox has angle measurement) are based on 10Hz GPS receiver, makes them quite accurate.
_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[DutchPug]

Than your car is very light indeed. Mine is 1180kg as it is now (without me in it), with fuel tank 1/2 filled.

Perhaps interesting to know my other 924 with 968 engine is 1184 kg also with fuel tank about 1/2 filled. Weight distribution on this one is 50.2 front and 49.8 rear. Battery still in the front.

The Gtech competition pro is just an accelerometer.

[Raceboy]

Went to the racetrack today, first time with current setup. Car felt quite ok, but I need more track time to get confidence with the car and max out the limits.
Sun was shining, but temperature was just 5C.

The BMW 2002 that blasts by is equipped with 700+ hp 2JZ engine, its prime goal is to be a drift car but owner takes it to racetrack occasionally.

Here's a vid of a lap (forgot to charge GoPro battery and it died when video ends): http://youtu.be/tuATUozMIlU
_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[morghen]

nice, the right window is wobbly at speed
_________________
https://www.the924.com

[Raceboy]

Yes, it was very nice to drive but already cannot wait for the spring to get more laps in it and get more familiar with the car. Also TODO list tripled with just one event without any serious causes

Found quite a cool shot of the event also:


_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche