Mafless S.D. tuning has begun!
Thread Starter
TECH Enthusiast
Joined: Aug 2003
Posts: 596
Likes: 0
From: Downers Grove,IL
Thanks for the offer Kevin. I'll take you up on it.
If I can't find a way to make this 4l60e shift into 3rd, I may just park the beast until I can afford to drop in a th400 and put any more tuning on hold for now.
If I can't find a way to make this 4l60e shift into 3rd, I may just park the beast until I can afford to drop in a th400 and put any more tuning on hold for now.
There is really no need for a 2 bar map sensor with a belt driven supercharged car.
Boost is a function of throttle position, and rpm of the blower and not load.
Boost is a function of throttle position, and rpm of the blower and not load.
Thread Starter
TECH Enthusiast
Joined: Aug 2003
Posts: 596
Likes: 0
From: Downers Grove,IL
I was able to setup map cell 105 where it was plenty rich for 40% or less throttle and then use the pe table to come in at 45% at low rpm part throttle boost situations for further enrichment.
With an auto, it's fairly easy as wot in any gear flashes the converter up, so no need for low rpm full boost mapping as it just won't ever happen.
The only real reason a 2bar map sensor is probably needed is for the big weather changes. In cold weather I'll pickup close to 2lbs of boost.
So having more WOT mapping would really come in handy. But if somebody is willing to always reprogram map cell 105 for boost or weather, then you do not even need a 2 bar map sensor for a belt driven supercharged car with a decent stalled auto backing it up.
Steve
With an auto, it's fairly easy as wot in any gear flashes the converter up, so no need for low rpm full boost mapping as it just won't ever happen.
The only real reason a 2bar map sensor is probably needed is for the big weather changes. In cold weather I'll pickup close to 2lbs of boost.
So having more WOT mapping would really come in handy. But if somebody is willing to always reprogram map cell 105 for boost or weather, then you do not even need a 2 bar map sensor for a belt driven supercharged car with a decent stalled auto backing it up.
Steve
TECH Resident
iTrader: (3)
Joined: Nov 2001
Posts: 979
Likes: 0
From: Richmond, VA Where fast cars, well......are hard to come by.
I logged a bit the other day with the maf disconnected, and it ran better part-throttle wise than ever. Zero program changes, just got out of class and unhooked it and drove home. Didn't try any map levels over ~75. My afr logged on the wideband shows to be smoother than with the maf, yet still stayed at 14.7:1. Kinda leary about positive pressure w/o the maf though...
Teching In
Joined: May 2004
Posts: 19
Likes: 0
From: Sydney, Australia
Dropping the MAF is the in thing down here now (only concerns are with warranty).
Done in the hands of a good tuner (of which there aren't too many), a MAFLESS tune releases a few more hp, but more importantly aids in driveability.
The Callaway C4B in the HSV GTS down here, first released in I think 99 had no MAF. So Reeves has been doing it for a while, thought you guys were too.
There are some here that still believe it is better, but it appears the MAFLESS tune is becoming more popular than a MAF tune.
Done in the hands of a good tuner (of which there aren't too many), a MAFLESS tune releases a few more hp, but more importantly aids in driveability.
The Callaway C4B in the HSV GTS down here, first released in I think 99 had no MAF. So Reeves has been doing it for a while, thought you guys were too.
There are some here that still believe it is better, but it appears the MAFLESS tune is becoming more popular than a MAF tune.
Thread Starter
TECH Enthusiast
Joined: Aug 2003
Posts: 596
Likes: 0
From: Downers Grove,IL
I loaded my Maf tune back in just to compare. No doubt cruise and drivability are crisper with the S.D. mode! But right now my WOT tune is better with the maf.
Since I'm using a 85mm maf on the pressure side, the maf is no restriction at all so I'm probably not going to see any peak power gains either way.
So it boils down to ,Do I want to take the time to dial in S.D. mode that potentially might be way off when big weather changes happen with the blower?, or keep the Maf tune and deal with a little soggier drivability.
Or just push the car off a cliff and forget all about it?
hmmm...decisions...
Since I'm using a 85mm maf on the pressure side, the maf is no restriction at all so I'm probably not going to see any peak power gains either way.
So it boils down to ,Do I want to take the time to dial in S.D. mode that potentially might be way off when big weather changes happen with the blower?, or keep the Maf tune and deal with a little soggier drivability.
Or just push the car off a cliff and forget all about it?
hmmm...decisions...
TECH Addict
Joined: Jul 2002
Posts: 2,261
Likes: 0
Originally Posted by HumpinSS
I guess the manual guy would benifit from this.
Joel
driving around in normal conditions the PCM isnt applying full pressure to the clutch packs in the tranny. It uses the MAF to figure this out. Without the MAF it sends full pressure to the clutch packs and could burn out the pump under these conditions. This is my understanding hopefully I didnt spread any misinformation. WOnt be the first and definately wont be the last
:yup:. A vacuum modulated tranny would vary the line pressure to the clutch packs using a acum signal like a vaccum advance distributor
HTH
Joel
driving around in normal conditions the PCM isnt applying full pressure to the clutch packs in the tranny. It uses the MAF to figure this out. Without the MAF it sends full pressure to the clutch packs and could burn out the pump under these conditions. This is my understanding hopefully I didnt spread any misinformation. WOnt be the first and definately wont be the last
:yup:. A vacuum modulated tranny would vary the line pressure to the clutch packs using a acum signal like a vaccum advance distributor HTH
joel
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
