How much does tuning help drivability?
Thread Starter
Launching!
Joined: Jul 2004
Posts: 200
Likes: 0
From: Gainesville, Florida
How much does tuning help drivability? I'm considering getting an ASA cam (226/236 110 LSA, .525/.525) for my daily driver and occasional road course car. Some people say it will suck to daily drive, others say you can make anything perfectly streetable with good enough tuning. I've got HPTuners and a FJO wideband, so tuning it won't be a problem.
Now I'm no stranger to tuning ECUs. I've messed with tons of different types of piggybacks and standalones on DOHC turbo motors. Never anything with a really aggressive cam though, and never touched a pushrod motor. One thing I can't figure out, why would a MAF car would require a different fuel map with a cam? Seems odd. If it were speed density I would understand... I haven't read much about the details of tuning these ECUs, but I'm guessing the ECU can ignore the MAF if its readings get really out-of-wack with the MAP sensor.
I wish there was someone near me with a cammed LS1, but there isn't. I'm worried the car will shake violently at idle, or buck like crazy under 2000 rpm. I guess what I want to know is, will I be able to tune out the drivability problems? Even with no cats, the car should be pretty quiet with stock Z06 mufflers, so an idle of 900 or 1000 rpm would be fine.
Thanks for any help.
Now I'm no stranger to tuning ECUs. I've messed with tons of different types of piggybacks and standalones on DOHC turbo motors. Never anything with a really aggressive cam though, and never touched a pushrod motor. One thing I can't figure out, why would a MAF car would require a different fuel map with a cam? Seems odd. If it were speed density I would understand... I haven't read much about the details of tuning these ECUs, but I'm guessing the ECU can ignore the MAF if its readings get really out-of-wack with the MAP sensor.
I wish there was someone near me with a cammed LS1, but there isn't. I'm worried the car will shake violently at idle, or buck like crazy under 2000 rpm. I guess what I want to know is, will I be able to tune out the drivability problems? Even with no cats, the car should be pretty quiet with stock Z06 mufflers, so an idle of 900 or 1000 rpm would be fine.
Thanks for any help.
TECH Regular
Joined: Apr 2003
Posts: 413
Likes: 0
From: Atlanta, GA
Originally Posted by Grant B
I'm considering getting an ASA cam (226/236 110 LSA, .525/.525) for my daily driver and occasional road course car. Some people say it will suck to daily drive, others say you can make anything perfectly streetable with good enough tuning. I've got HPTuners and a FJO wideband, so tuning it won't be a problem.
Now I'm no stranger to tuning ECUs. I've messed with tons of different types of piggybacks and standalones on DOHC turbo motors. Never anything with a really aggressive cam though, and never touched a pushrod motor. One thing I can't figure out, why would a MAF car would require a different fuel map with a cam? Seems odd. If it were speed density I would understand... I haven't read much about the details of tuning these ECUs, but I'm guessing the ECU can ignore the MAF if its readings get really out-of-wack with the MAP sensor.
I wish there was someone near me with a cammed LS1, but there isn't. I'm worried the car will shake violently at idle, or buck like crazy under 2000 rpm. I guess what I want to know is, will I be able to tune out the drivability problems? Even with no cats, the car should be pretty quiet with stock Z06 mufflers, so an idle of 900 or 1000 rpm would be fine.
Thanks for any help.
Now I'm no stranger to tuning ECUs. I've messed with tons of different types of piggybacks and standalones on DOHC turbo motors. Never anything with a really aggressive cam though, and never touched a pushrod motor. One thing I can't figure out, why would a MAF car would require a different fuel map with a cam? Seems odd. If it were speed density I would understand... I haven't read much about the details of tuning these ECUs, but I'm guessing the ECU can ignore the MAF if its readings get really out-of-wack with the MAP sensor.
I wish there was someone near me with a cammed LS1, but there isn't. I'm worried the car will shake violently at idle, or buck like crazy under 2000 rpm. I guess what I want to know is, will I be able to tune out the drivability problems? Even with no cats, the car should be pretty quiet with stock Z06 mufflers, so an idle of 900 or 1000 rpm would be fine.
Thanks for any help.
tuning will make a night/day difference. I have a TSP225 on 112 and that thing would buck under ~2200 rpms, Hunt for idle, Die in the parking lot, die backing up, die coming to a stop. Shake like Catherine Hepburn at idle....with tuning it is not too far from stock. Only slight bucking occasionally, and periodic idle hunt. SES light now and then from the shake. You can do it, but it will not be "stock" - but it can be driveable.
Trending Topics
Thread Starter
Launching!
Joined: Jul 2004
Posts: 200
Likes: 0
From: Gainesville, Florida
Originally Posted by monodax
The GM code weights the speed density tables much greater than the MAF input in the lower RPM ranges. Once over 4000 RPM it is almost totally based on the MAF input while in steady state mode. It uses the speed density tables almost always to sanity check for transient conditions such as throttle blades closing.
I know big cams can be a problem for speed-density setups with big cams because of the vacuum fluctuations at low RPM. More intelligent sampling of the MAP sensor is needed, I know some ECUs pick a specific crank position to sample the MAP sensor voltage to calculate load, instead of a fixed frequency. Others can perform software filtering based on RPM, which is what I've done in the past.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
TECH Addict
Joined: Feb 2004
Posts: 2,826
Likes: 0
Originally Posted by monodax
The GM code weights the speed density tables much greater than the MAF input in the lower RPM ranges. Once over 4000 RPM it is almost totally based on the MAF input while in steady state mode. It uses the speed density tables almost always to sanity check for transient conditions such as throttle blades closing.