The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support Fuel Injector Clinic
Please Support ExtremePSI

General How much does a stage 1 cam change a tune?

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

SasaniFab

Proven Member
2,433
782
Dec 1, 2013
Mexico, Connecticut
I am currently running a stock block 6 bolt, fp green with 1000cc injectors, full fuel system Dsm link etc. I recently installed a set of gsc stage 1 cams with springs and retainers and I'm seeing a ton of knock at low speed, 4th gear at speed it will pull to redline though. The car was never really tuned and was running rich. Would a set of gsc s1 cams really effect the tune that much?
 
im aware that the 1g timing curve is aggressive, more timing at lower rpms, should I be pulling timing or adjusting the cam gears or both?
 
It was very strange, like the car wont accelerate, almost like the car is retarding the shit out of it. Im new to dsm link and was messing with the tune last night. The car is not doing it anymore. I did a pull on 20psi and it pulled hard with no knock. Im gunna post the log tonight I want to see what people think, everything is ass backwards in the tune as far as im concerned. I am getting 376 on the hp calculator.
 
There are so many threads, videos, and a whole wiki dedicated to helping you not have a back asswards tune. Maybe start there?
 
Would a set of gsc s1 cams really effect the tune that much?
A longer-duration cam increases the overlap and promotes better evacuation of the cylinders through scavenging from the exhaust port. This will effectively lower the vacuum in the intake manifold as well. By increasing overlap and leaving the intake valve open longer you're bringing more air into the cylinder each combustion cycle from idle to redline. This will typically make your tune leaner, which is why you should never install cams in a car that doesn't have some type of tuning platform or it will run like garbage.

I am getting 376 on the hp calculator.
Never accurate. You're probably closer to 276 than you are 376 if you put it on the rollers at this very moment.
 
It may go slightly lean in some rpm areas due to increase in airflow. How much depends on how aggressive the cams are. Now days stage one like Kelford 26X and BC272 has very aggressive lifts that 10 years ago we would of considered them stage 2's
 
I say ass backwards because Im new to tuning, I can build an engine sure, but understanding tuning is another science in itself. The car idles and pulls to redline without knock. i posted the log in the fuel management section
 
Like i said before, you really need to watch the videos and read the "tuning 101" wiki page on ECMlink. First off, log your fuel trims. Based on your STFT, and "selectedLTFT" they are off and need to be adjusted. Your selected LTFT looks to be maxed out. It is trying to compensate for all that extra air. Your airflowperrev is about double what it should be (target of .25) your isc is too high (target 30). Getting these dialed in should help your front O2 sensor look more normal and the car idle better. Lastly, your WBFactor is off a little bit. It could use some tweaking.​
 
l have all of that printed out, watched the videos, watched all of jafros videos 10x over. I appreciate you taking the time to look, I'm not asking for help, just showing my progress. I'm still learning obviously. I was under the impression with cams my airflow per rev will be >.30? Thanks again
 
You may be right about the cams, but before you start making pulls you should be getting everything set up right, otherwise you are just chasing your tail. YOu could have all the idle stuff dialed in in about 30 mins maximum in your garage.

I'm seeing a ton of knock at low speed, 4th gear at speed it will pull to redline though. The car was never really tuned and was running rich. Would a set of gsc s1 cams really effect the tune that much?

should I be pulling timing or adjusting the cam gears or both?

everything is ass backwards in the tune as far as im concerned. I am getting 376 on the hp calculator.

Sounds like asking for help to me, but since you don't want any, good luck with the car.
 
You know what it is man, I'm finding that people assume that a person can read a bunch of literature and understand how to apply it in the real world. When people ask for help they get hey dummy have you read this and watched that! Maybe it's a good thing, it forces people to do their homework.
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top