968 Supercharger Kit Development
#856
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Hats off to you Carl - well done on producing a kit at the price you have and in communicating the development very clearly - all really good.
I had my 968 clubsport supercharged five years ago, and I haven't looked back - it's fantastic.
Congratulations - I really ought to check Rennlist more often.
Fraser.
I had my 968 clubsport supercharged five years ago, and I haven't looked back - it's fantastic.
Congratulations - I really ought to check Rennlist more often.
Fraser.
#858
Nordschleife Master
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Just back from the dyno. I'll start with the bad news. Adding both the high flow fuel pump and larger injectors did not work. Why, toooooooooo much fuel. Without a standalone system, there's no way to make it work.
Now for the good news. I put my Bosch gen 3 injectors back in and we started fresh. After a few pulls and a few tweeks, we got it going very well. And the numbers are:
Max rwhp: 307
Max rwTQ: 252
Max boost: 5.9 lbs
Clearly I'm very happy with the results. I was hoping for 304 on a dynojet and I beat that number on a mustang. Guess I'm going to have to add weight to make my class. My previous run in NA form back in April (on the same mustang dyno):
Max rwhp: 211
Max rwTQ: 186
If you do the math, that's a gain of 96 rhwp and 66 ft lbs of TQ. I'll scan the dyno tomorrow and post. In the meantime, here's the video of the pull
http://www.vimeo.com/15827543
Of interest is the fact that at 6500 rpms, the HP is still climbing. We did not go higher, so I don't know where it starts to decline. The AFR was if anything rich, running around 11. I showed Jim (dyno operator) Carl's post about running at 12 but he thought that was too lean for a track car, so we left it at 11. The AF was not as smooth as I saw before in NA form, but I'm guessing that we are using high fuel pressure to drive fairly small injectors.
Now for the good news. I put my Bosch gen 3 injectors back in and we started fresh. After a few pulls and a few tweeks, we got it going very well. And the numbers are:
Max rwhp: 307
Max rwTQ: 252
Max boost: 5.9 lbs
Clearly I'm very happy with the results. I was hoping for 304 on a dynojet and I beat that number on a mustang. Guess I'm going to have to add weight to make my class. My previous run in NA form back in April (on the same mustang dyno):
Max rwhp: 211
Max rwTQ: 186
If you do the math, that's a gain of 96 rhwp and 66 ft lbs of TQ. I'll scan the dyno tomorrow and post. In the meantime, here's the video of the pull
http://www.vimeo.com/15827543
Of interest is the fact that at 6500 rpms, the HP is still climbing. We did not go higher, so I don't know where it starts to decline. The AFR was if anything rich, running around 11. I showed Jim (dyno operator) Carl's post about running at 12 but he thought that was too lean for a track car, so we left it at 11. The AF was not as smooth as I saw before in NA form, but I'm guessing that we are using high fuel pressure to drive fairly small injectors.
#859
Three Wheelin'
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Great work Tim!
You might want to keep tabs on what Rogue_Ant is doing - this might solve your ECU tuning worries... check out his website.
Cheers,
Mike
You might want to keep tabs on what Rogue_Ant is doing - this might solve your ECU tuning worries... check out his website.
Cheers,
Mike
#860
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If only mine ran as well and produced that
307 at the weels, COOL
I shall be fitting the a/c comp this weekend and running it to see if I have eradicated the belt slip. Next will be to wind out the fmu and try the injectors again, you are running stock injectors now Tim?
Will try that, then a 3 BAR FPR and my 7100 chip to see what I get.
Still along way to go to get above the 230 RWHP I have at the moment
![Frown](https://rennlist.com/forums/images/smilies/frown.gif)
I shall be fitting the a/c comp this weekend and running it to see if I have eradicated the belt slip. Next will be to wind out the fmu and try the injectors again, you are running stock injectors now Tim?
Will try that, then a 3 BAR FPR and my 7100 chip to see what I get.
Still along way to go to get above the 230 RWHP I have at the moment
#861
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If only mine ran as well and produced that
307 at the weels, COOL
I shall be fitting the a/c comp this weekend and running it to see if I have eradicated the belt slip. Next will be to wind out the fmu and try the injectors again, you are running stock injectors now Tim?
Will try that, then a 3 BAR FPR and my 7100 chip to see what I get.
Still along way to go to get above the 230 RWHP I have at the moment
![Frown](https://rennlist.com/forums/images/smilies/frown.gif)
I shall be fitting the a/c comp this weekend and running it to see if I have eradicated the belt slip. Next will be to wind out the fmu and try the injectors again, you are running stock injectors now Tim?
Will try that, then a 3 BAR FPR and my 7100 chip to see what I get.
Still along way to go to get above the 230 RWHP I have at the moment
Fraser.
#863
Nordschleife Master
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If only mine ran as well and produced that
307 at the weels, COOL
I shall be fitting the a/c comp this weekend and running it to see if I have eradicated the belt slip. Next will be to wind out the fmu and try the injectors again, you are running stock injectors now Tim?
Will try that, then a 3 BAR FPR and my 7100 chip to see what I get.
Still along way to go to get above the 230 RWHP I have at the moment
![Frown](https://rennlist.com/forums/images/smilies/frown.gif)
I shall be fitting the a/c comp this weekend and running it to see if I have eradicated the belt slip. Next will be to wind out the fmu and try the injectors again, you are running stock injectors now Tim?
Will try that, then a 3 BAR FPR and my 7100 chip to see what I get.
Still along way to go to get above the 230 RWHP I have at the moment
I should mention that I did not run the dynos last night with an open pipe. Instead I welded an O2 bung into the exhaust so that I could run it with my supertrapp discs in place since that is how it will be run on the track.
As promised, the last dyno run from last night is below
![thumbsup](https://rennlist.com/forums/graemlins/bigok.gif)
![](https://dl.dropbox.com/u/8640689/Resurrection%202010/Dyno2.jpg)
Last edited by Lemming; 10-14-2010 at 10:23 AM.
#864
Developer
Thread Starter
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Well done. That AFR line is probably about the best you can do with the stock ECU that you are running. You will not be able to get it any flatter until you get an aftermarket Engine Management System in there.
You are giving up about 15 HP running that rich.... when you get an EMS installed and can nail 12.0:1 across the board expect to gain that 15 HP back. But for now, it adds safety and thats good.
Go racing and enjoy the car!
You are giving up about 15 HP running that rich.... when you get an EMS installed and can nail 12.0:1 across the board expect to gain that 15 HP back. But for now, it adds safety and thats good.
Go racing and enjoy the car!
#865
Developer
Thread Starter
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Please clarify: after you installed the aftermarket bigger fuel pump, you found that the Stage 2 injectors we supplied were now too large. Do I have that right?
Did you go back to the stock injectors? Or to some injectors bewteen stock and the ones we sent?
Did you go back to the stock injectors? Or to some injectors bewteen stock and the ones we sent?
#866
Nordschleife Master
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To be honest, I now have too much HP
![EEK!](https://rennlist.com/forums/images/smilies/eek.gif)
#867
Developer
Thread Starter
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To be honest, I now have too much HP
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#868
Developer
Thread Starter
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Seriously, yes - if you have so much HP that it bumps you into another class/division - it can be a problem. You try to build to be at the max of the regulations for a division, rather than being just at the entry point of the next division. The difference is being one of the faster cars in Group B or one of the slower cars in group A.
My recommendation for dialing the HP back just a bit is a larger pulley on the supercharger. It will move the entire curve up a bit but it will stay the same as it is now. To a racer - it only means that the boost comes in a little later and that rarely matters.
But - the larger pulley also means higher tractive force (less belt slip), cooler induction temps (greater engine safety) and longer service intervals (time between rebuilds). All good.
If you dont have the pulley size you want, I can make one for you.
My recommendation for dialing the HP back just a bit is a larger pulley on the supercharger. It will move the entire curve up a bit but it will stay the same as it is now. To a racer - it only means that the boost comes in a little later and that rarely matters.
But - the larger pulley also means higher tractive force (less belt slip), cooler induction temps (greater engine safety) and longer service intervals (time between rebuilds). All good.
If you dont have the pulley size you want, I can make one for you.
#869
Nordschleife Master
#870
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Rennlist Member
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You could also put a wastegate on the IC piping, to limit your boost. This way you would still maintain the same (early) torque curve, and have control over max HP.