RideZX6R

So I installed an MS4, TEA Stage 2 LS6 heads, ported FAST 102mm, ported LS2 TB, etc in my 99 FRC.

I like the power and how fast it feels and how it scream thru the rev-range, however the idle is terrible - bouncy and annoying and I'm wondering if this can be tuned out or if it's something I need to live with (ie I should have gone less aggressive with my cam choice).

The car will start up and idle at 950-1050 when dead cold, however when its warming up driving and sometimes when its warm (half the time maybe?), when I push the clutch in coming to a stop sign/light, the car will drop to 450rpm, the ECU picks up on it and throws some timing at it and it'll bounce to 1200ish and then it'll either level out at 900ish or (most often) it'll bounce from 500-1200 back and forth.

My buddy tuned the car, he's always made power with my cars and others, however he usually tunes turbocharged stuff not big cam cars. So I'm wondering if I can mail it in somewhere and have them fix it ...
or even if someone wants to provide help with me, I was thinking of buying HPTuners for myself so I can adjust stuff on the car all on my own.

What do you guys suggest? How should a well-tuned MS4 car do?

*edit* in case anyone feels like looking it over - here's the HPTuners file - http://www.mediafire.com/?op7asa1acao7w6p

Logg

I've had a few C5's that were built beyond stock and I believe you should be able to tune that out. The last 2 heads and cam cars I've had I notice that the cars are set up to keep a high idle (1200-1300rpm) when rolling with clutch pushed in untill the ecu sees absoluet 0 mph then drops the idle down to about 900rpm. The cars I've had set up like that do not hunt for idle when stopping like you describe. I've also had cars set like your's now. The key seems to be something added in the tune to be 0 mph before dropping rpm's to idle.

tblu92

I've never had an engine that i couldn't get to idle correctly--Not surge--or not die-- It's all tunable---1st you made several MAJOR mods all at once--The cam aone would take hours to get right but adding the Fast 102 takes another whole tuning process--Trouble with too many mods at once is that you start chasing your tail when trying to sort out which tables to correct--And which mod is causing the issue--
A dyno tune only tunes for optimum HP at WOT only--So i would guess that's all they did and why it runs strong there---however the driveability issues that you have require a "street driven tune" to sort out the surging/idle/dying problems--This can take hours of data logging and adjustments bescause you would have to let the ECM leearn out some in between changes or again you're chasing your tail--
As a starter--Did the original tuner do a "crank position re-learn procedure " ?? This is always reccomended--

edcmat-l1

It's tunable. I sell HPtuners and tuning support. Send me an email if you're interested. edcmat-l1@msn.com is my email.

CTD

Option #4 bigger cams are tough, Ed has the background & experience.

RideZX6R

emailed

RideZX6R

added hptuners file to the original post

LSOHOLIC

From all that I've read and heard first hand, you will be in good hands with Ed. He seems to be a master of his craft and I hear quite the perfectionist.



Thanks...............

CTD

I just had a quick look, by chance do you have a log to go with it? One the shows the drive ability problems.

I'm certainly not a pro tuner, just a backyard home grown tuna. Like most tuning became an afterthought, relying on others & never getting there. So I've had to learn, first to try & get the POS running correctly, secondly to be able to differentiate between tuners, wannabe tuners, hacks, good tuners & Pro's.

The 99 has some limitations with the ECU compared to later models, so you might benefit further with Ed's experience there.

Your tune is currently MAF only, which is a nice way to run the car if it will run that way. There are certainly a few things that can help your drive ability issue's, generally no silver bullet's. You may also find it may run better in SD, if tuned properly it will run in both configurations.

I agree with your about buying some tuning software & getting on with it, your car with your combination needs help.

DARRYLZO6

What they said. I would also look around for any vaccuum leaks,like hoses.

wjr152

Anything under 1500rpms and the car bucks pretty fierce. I keep reading that it can be tuned out, but I went to RPM in Southern California bc I always heard they are one of the best. Austin from there said the ms4 was just too big and it can't be tuned out. Is RPM no good now that Charlie left?

jglassmaker

MS4 cam here, even took mine to a "pro" dyno tuner shop (locally) and it was still pretty bad.

I have been learning and tuning the car myself after resetting to a stock tune, and it is actually not that bad at all anymore. You would not believe how much a really good tune can do for drivability!

You probably went too big for what you like, so now you just need to put a lot of time and money into getting the tune right. It makes a world of difference with the big cams like MS4.

onspeed

4 year old thread - hopefully he figured it out by now.

jerkyboy

Hope he figured it out and I would like to hear as I have a similar sized cam and have the exact same issues.

jglassmaker

A lot of it is in the tune. I have the MS4 cam and had tons of issues with startup and takeoff and massive cam surge. I have since fixed so much of it that I have to have other drivers try driving my car to tell if I am making any improvements anymore - it just all feels perfect to me but I am just so used to how the car was.

jerkyboy

I guess it's just finding the right tuner with the right mojo to figure this out. I've been to a few (and one considered one of the best) and been told "the cam is too big".

My cam is 232/244 .630ish lift on a 112 so not even as big as an MS4 and I'm running 427 ci. The surge I can live with, the rolling clutch in rpm flux makes sitting in traffic a nightmare.

jglassmaker

I am not all that surprised you were told that even from some of the best... I have spent 100s of hours (maybe 300+ now) tuning mine over a month+ and I still have a ton of fine tuning to do. I have done LT1 tuning before with various cams but this new Gen III PCM gives you so many options on how to deal with larger cams it just takes so much time to play with.

There are some very good guides on how to get you started, but so much of it cannot be simply logged into a histogram and calculated into tables. It is very critical you get those tables you can as close to perfect like VE, MAF, BAF.

The rest is going from feel and just random changes of trial and error. Every cam is different and even the same cam with different engines tend to be a little different for some strange reason.