ZCAT3

Thanks to Brent 930 and PorschePhd (Stephen Kaspar of Imagine Auto) I learned of a place that modfies and improves the flow of the CIS fuel head. Brent has already had this done. Well I just got my modified fuel head back yesterday, installed it last night, and went to the dyno today. As a point of reference, you can see my prior dyno run here: https://rennlist.com/forums/showthre...threadid=86871

So how did my modified fuel head do? Very good - my RWHP stayed the same as my last runs - 403, but my RWTQ went up from 425 to 438. I am running a K27 7200 turbo and no matter what I do the max boost I can get at peak power (5200 RPMs or so) is .9 bar. The great thing about today's run is that my max AF ratio was about 12 to 1 (previously it was 13 to 1). In fact, I am actually running a little rich at these levels. I never thought I would see the CIS system do so well. It looks like I could get some more HP under CIS, but would need to switch turbos. My car is a torque monster now so I see no need - I have over 400 RWTQ at 3300 RPMs and hold above that to about 5300 RPMs.

So with these numbers we are looking at approximately 475HP and 515 ft lbs torque. And I think I have discovered the upper limit of the K27 7200. As I have a digital adjustable boost controller and monitor, I can actually watch as the turbo struggles to hold boost much past 5000 RPM. In fact it is dropping off already at that point.


I will post the dyno run later today. One thing of note is that I meant to completely turn off my Andial Fuel Enrichment system for the dyno runs, but I forgot. It was only in the first position, so it probably did not make much of a difference. The place where the fuel enrichment systems work is from about 2800 RPM to maybe 4200 RPM (at least that is what I have seen in the various runs). You will see this on my AF curve. I may have a little better torque and power in that area if I had turned the enrichment off as I am pretty rich there.

jhunt@huntinter

Hp always passes Torque at 5200

ZCAT3

Here is the latest dyno compared to the pre-fuel head mod - you can see how much the fuel head modification improved my AF ratio. In fact, I think the car may be a little rich now and could suport some more HP. I forgot to turn off the Andial fuel enrichment or my midrange would have been smoother. Still, it is a big improvement and should let me run the turbo at its max output without worrying about fueling issues.

ZCAT3

You, sir, appear to be entirely correct!

Brent 930

Bill, good news and thanks. This fuel head mod is starting to catch on for us loyal CIS guys.

PorschePhD

Looks like this will be a common build in our motors now. We are doing the lower chamber swap on one now to eliminate the lambda control and make a "Euro" type head off of the US spec piece. Great stuff for the 930s I tell ya....Just that much cushion when making HP

MitchB

I will soon be yanking my CIS fuel head for a rebuild, so I'm happy there is someone who is doing good work.
Who/Where did this improved rebuild? Got a fone number?
How much was it?
Thx
M

Randy

Isn't the crossover at 5252 rpms Mr. Hunter? And have you seen those Lipansanser stallions....Give me my missile key!!!!

ZCAT3

Mitch - the gentleman who does the work will only do it through distributors. I worked with Stephen at Imagine Auto to get mine done, so you can contact him - porschephd@imagineauto.com

Man I love all that torque - I would have probably had an ever fatter torque band if I had remembered to turn the Andial unit off for one of the runs. Still, it is not a bad idea to have someextra fuel to keep heat down while under boost. In fact, that is one of the things I noticed during these dyno runs - the car ran substantially cooler under boost.

MitchB

Thx for the quick reply.
Stephan is my guy too, and will be getting some more of my business soon! I'll inquire with him.
Mitch

pig4bill

Yeah, and they're from Spain, not Portugal.

Randy

Maybe,........but they are all white when they're born....


Thanks, you gave me a good laugh at the end of a long day.

jhunt@huntinter

I don't get it :/

Randy

Sorry John, they're lines from a great submarine movie Crimson Tide with Gene Hackman and Denzel Washington, in which Washington's character was named "Mr. Hunter". His character was very cool incidentally. Your name just reminded me of the movie, that's all.