Speedwerx

Hello, I am an avid reader of this forum and have come to understand by many of you that because of the inherent nature of the CIS fuel system that safe gains in horse power would be limited somewhere in the region of 380hp at the wheel and 450 flywheel at 1 bar.

After several dyno runs I am pleased to say that I am producing consistent numbers of 415Hp and 420PTQ at the wheel. I must give credit to the knowledge and patience of my local tuner here in South Florida who has been able to extract such figures.

I am trying to determine whether or not there are others who have been able to obtain these sort of figures also with similar modifications.

A list of my modifications are as follows:

Custom Headers
Custom Exhaust
Light weight Flywheel & Clutch
Turbo S Cams
Custom Garrett Turbo (T-O4 Based)
Greddy Profec B (adjusted to 15lbs boost)

Secondly, although these gains are nice, ultimately I am trying to achieve figures in the range of 675HP. I would also like to know if any of you have achieved this result(675HP)with a retro fitted Motronics system or have any experience with a generally hassle free stand alone management system.

Although my goal is big hp I am not prepared to sacrifice drivability. My current tuner has an excellent reputation at achieving very good results with the motronics system and a custom twin turbo set up.

Would appreciate any feed back.

Thanks,
Speedwerx
<a href="http://home.earthlink.net/~earnestjones/" target="_blank">My cars Web Page</a> Before Mods

John from WA

Did you have an A/F gauge hooked up on your dyno run? You might be surprised at how lean you went with your CIS. At @450hp the stock "euro" or '78/'79 fuel heads are about at max. The US fuel head needs aux fueling like Andials or Rice's.

Speedwerx

</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by John from WA:
<strong>Did you have an A/F gauge hooked up on your dyno run? You might be surprised at how lean you went with your CIS. At @450hp the stock "euro" or '78/'79 fuel heads are about at max. The US fuel head needs aux fueling like Andials or Rice's.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva"> Intresting observation, as a matter of fact the dyno did have a AF meter and yes the car leaned out at 13.3 @ 6200 rpm. I have subsequently fattened the mixture a bit using the limited one dimentional adjustment offered through the CIS system.

Could you or anyone please provide a bit of information on both the Andial and Rice fuel inrichment product and the premise of it's operation.

Thanks,
Speedwerx

Speedwerx

Bruce M.

News bulletin--there ain't no such thing as a "hassle free engine management system". They can be tweaked to work, but they take time and effort, especially on cold start and idle issues. If you have the dough, I'd go with the Motec M800. I have its predecessor, the Motec M48.

As to 675 hp, if you are talking a single turbo on a 3.3 liter, and you are talking to the wheels on a legit dyno, and you want street driveability with not too much lag, that's a very tall order. Don't know anybody who has done it, actually.

I get just over 700 to the crank, on a 3.45 liter with Motec, at 1.4 bar. About 600 to the crank at 1 bar.

I second the A/F comments--your tuner better know what he is doing, and doing max power runs on a dyno without an A/F meter is not standard operating procedure, to put it kindly. Maybe he did it, though, and you just didn't tell us.

There's an old saying on engines--they always run their best just before they grenade. And lean is very, very bad for longevity.

Speedwerx

I appreciate the comments, however I make it a good habit of being reasonably thorough when asking a question or posting a comment on this and any forum.

As I indicated earlier.. The dyno was indeed equipped with an A/F meter and the needed adjustments were made to ensure continued safe operation.

Also, I do understand that a stand alone management systems install and operation is only as good as it's tuner. My question was directed more towards hardware and software reliability issues more than anything else.

I will try to be more clear non the less. Thanks for the observations.

Speedwerx

Bruce M.

Apparently, your second message and my response to your first message crossed in the ether.

If you're willing to go twin turbo, I believe you can get to your 675 at the wheels goal (if that's what it is). Once a good engine managment system is installed with the correct sensors and dialed in on a dyno (best is an engine dyno first), then neither hardware nor software should be an issue. It's my understanding that a proper twin turbo set-up will allow for both decent low-end response and great high end performance, but in my experience, the best thing I did for low-end torque and off-boost driveability was go to a 3.6 crank. The stroker really seemed to give the engine more life down low. You have to chamfer the heads a bit to accomodate the larger stroke, but if your guy has done these hop-ups before that shouldn't be a problem. Of course you need rings cut into the heads as well for the kind of numbers you're looking for.

Good luck. But a word to the wise from someone who has been there before--over about 450 hp, you REALLY start getting traction-limited in these cars. When I'm running on 110 at 1.4 bar, I have 575 ft-lbs of torque at the wheels, and it takes a practiced foot not to shred tires big time with that kind of twist, and even then things can get very hairy.

In other words, the extra money to get the 100 marginal hp and ft-lbs often just goes up in tire smoke. Didn't really figure that out until I got here...

Speedwerx

Thanks Bruce for the insightfull and practical info. Are you running a twin turbo set up? If so which Turbos ( make and model) did you elect to use?

Speedwerx

Bruce M.

Nope. Single, AirResearch/Garrett TS04 turbo. Don't know what its flow limits are, but they are good enough for 700 +hp.

ZCAT3

Hmm - you are running about 488 HP at the crank, which is the most I have heard of using the CIS fuel system - even with an Andial enrichment system in place. I estimate I am running 450 at the crank at .8 bar and maybe 480 at 1 bar. I do have fuel enrichment and all of the goodies and would not feel comfortable going beyond this. I suppose I could crank it up to 1.1 or 1.2 to see if I can pass the 500 HP barrier, but this engine cost an awful lot to get to where it is

Sameer

ZCAT3,
It's not worth risking your engine for that few extra 20-30 ponies. I myself keep my boost just below 1 bar. However 1 to 1.05 is still within the safe range with good fuel, adequate cooling and enrichment as added safety.

ZCAT3

Hi Sameer -

I have been playing with my G-Tech Pro a bit lately and thought I would do some HP runs. As you may know, the G-Tech is actually quite accurate. Well the first run I did the car lost traction in both first and second gear - that was a bit hairy and gave me a skewed HP number. I think I lost traction because I did something I do not normally do. I pulled into the lane from the side of the road and eased up to maybe 3,000 RPMs. I was not running any boost doing that. Then I pushed it to the floor and the boost came on all at once. I fish-tailed a bit to the left in first and then back to the right in second. I think I got like 264 RWHP stated on that run. No shock as I wasn't moving forward very much. I am running 18x11s in the rear, so traction is usually not an issue. I was only able to get a few decent runs where I didn't screw up out of maybe 5-6 tries and then called it quits as it was scaring me a bit (yeah, I'm a wuss).

So here is the number - running at a very precise .8 bar: 408 RWHP. Using the 15% drive train loss, that is 480 HP at the crank at stock boost using pump gas. Not too shabby. I wonder what 1 bar would do (not that I am going to try that).

Sameer

ZCAT3,
Thats some good numbers your producing.

ZCAT3

Yeah - that seems like an almost amazing number for .8 bar. The average of the runs was around 394 RWHP, or 464 at the crank. I was hoping to see 450 at .8 bar when we embarked on this engine upgrade so I am pleased with the results.

Sameer

ZCAT3,
What sort of mods do you have for producing these nos? You still using 3.3 or 3.4? Want to fill us in with details on your mods?