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.

 

Thanks Fraser, I appreciate it. The check is in the mail

 

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.

 

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

 

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

 

Good luck Chris - let us know how you get along.

Fraser.

 

You are most very welcome, Carl

 

I'm waiting for him to map the 968, then I'm in business!

Chris, once you get the belt worked out, you should be good. I am not running stock injectors, I am running the bosch generation III replacement injectors, these are the 32lb injectors found in Ford Mustangs. There is another thread on this board that details them.

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

 

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!

 

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?

 

Carl, I got a stage I kit from you. On the original dyno day, I was running Bosch Gen III 968 replacement injectors for the 968. They are rated at 32lbs at 43.5 psi. I then purchased larger injectors which were 42 lbs. With the Welbro and 42 lb injectors, I was far too rich. Removed the 42 lb injectors and put the 32's back in. That is the setup for the dyno above.

To be honest, I now have too much HP My target for the racing class was 305 rwhp on a dynojet. I'm guessing that I will be 330+ on a dynojet and will have to run way too much ballast. Any suggestions on hp reduction without losing the nice TQ curve?

 

... a problem similar to having too much money. I've heard of this problem, although I have never experienced it.

 

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.

 

Yea, but my other option is to add 252 lbs to my car to make class

Hmmm, I could supersize my meals for the next year and maybe get there!

 

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.