General/Simple opinion regarding tune tweaks for gear swaps
08-22-2009, 12:45 AM
#1
General/Simple opinion regarding tune tweaks for gear swaps Heay Guys
Am getting ready to bump my rear end gearing from 3.55 to 3.90. Seems as though I should richen the PE table a tenth or so across the board from maybe 2800 through red line during WOT (not 10%, but -0.10 in A/F ratio). Basically, a decrease from 3.55 to 3.90 is about a 10% increase in acceleration. So, figured making the PE table a tad richer as noted would help to reduce any resulting fueling lag @ WOT. Will check the tune to confirm this, eventually. Would help to have confirmation from pros &/or guys who have done this. Thanks in advance
Am getting ready to bump my rear end gearing from 3.55 to 3.90. Seems as though I should richen the PE table a tenth or so across the board from maybe 2800 through red line during WOT (not 10%, but -0.10 in A/F ratio). Basically, a decrease from 3.55 to 3.90 is about a 10% increase in acceleration. So, figured making the PE table a tad richer as noted would help to reduce any resulting fueling lag @ WOT. Will check the tune to confirm this, eventually. Would help to have confirmation from pros &/or guys who have done this. Thanks in advance
08-22-2009, 07:21 AM
#2
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Not 100% sure on the logic of changing the PE table enabler(s) based solely on a gear change. When you change the gear ratio, you will just simply hit the resulting PE RPM Enable sooner.
While I think I know what you are getting at, with high quality tuning software you can always 'edit' out any PE delay..no matter what gear ratio you are at.
You can certainly manipulate PE enable by RPM/TPS according to your personal preferences. I do not recall changing the PE Table just for a gear change..I just put PE Delay RPM Bypass to zero and starting enrichment from 2400-2800 RPM's, and worked on the AFR's through TQ peak and Hp Peak.
If you have the tuning software and a wideband you can pretty much do want you want.
Hope that helps. Enjoy.
..WeathermanShawn..
While I think I know what you are getting at, with high quality tuning software you can always 'edit' out any PE delay..no matter what gear ratio you are at.
You can certainly manipulate PE enable by RPM/TPS according to your personal preferences. I do not recall changing the PE Table just for a gear change..I just put PE Delay RPM Bypass to zero and starting enrichment from 2400-2800 RPM's, and worked on the AFR's through TQ peak and Hp Peak.
If you have the tuning software and a wideband you can pretty much do want you want.
Hope that helps. Enjoy.
..WeathermanShawn..
08-22-2009, 10:05 AM
#3
Yah, I've got everyhting; software, wideband, tune wise. I sometimes forget that all of that info has been removed from my sig. My delay bypass is @ zero & the RPM/TPS is fairly agressive, as well. Currently, have my PE beginning @ 2800. So, perhaps lowering it will be the key.
Reason for the logic is fear of PCM or gear swap related lag. Although, the response is theoretically "lightning" fast, I have watched logged A/F ratios lag a bit @ times (even w/ delay set to 0) & wanted to stay on top of things by asking about any possible issues related to gear swaps & the tune.
BTW, 400 FT-#'s of torque @ 3500 RPM is freakin' sweet! Well done.
Reason for the logic is fear of PCM or gear swap related lag. Although, the response is theoretically "lightning" fast, I have watched logged A/F ratios lag a bit @ times (even w/ delay set to 0) & wanted to stay on top of things by asking about any possible issues related to gear swaps & the tune.
BTW, 400 FT-#'s of torque @ 3500 RPM is freakin' sweet! Well done.
08-22-2009, 10:29 AM
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Thanks for the compliment. If I ever doing it again I'll pick the more cubic inch method for an 'easy' balance of HP/TQ.
O.K., I finally figured out what you were getting at. Not a bad idea of starting PE at 2400 rpm's then. True, you will spin through those rpm's pretty quick..who wants any lag!
Nice build. Let us know how it goes.
..WeathermanShawn..
O.K., I finally figured out what you were getting at. Not a bad idea of starting PE at 2400 rpm's then. True, you will spin through those rpm's pretty quick..who wants any lag!
Nice build. Let us know how it goes.
..WeathermanShawn..
08-22-2009, 10:57 AM
#7
Consider this also:
While 2nd gear with 3.90 will go faster than 2nd with 3.55, it will not go faster than 1st with 3.55. The only possible lag could be in 1st gear.
I would measure the performance of each before I made that change permanent. Just my 2 cents.
While 2nd gear with 3.90 will go faster than 2nd with 3.55, it will not go faster than 1st with 3.55. The only possible lag could be in 1st gear.
I would measure the performance of each before I made that change permanent. Just my 2 cents.
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08-22-2009, 12:19 PM
#10
Some of the OEM cals have it set very high. 12212156 for example, which is a popular 02OS have it set at 5500, but you will see commanded fueling change as soon as you put your foot down hard (TPS and MAP met... possibly just TPS even).
I try to use the things that are available to us generally... You can tune burst knock to pull a little out on hard throttle. From the factory it is aggressive so many 0 it out, I use it toned down to fight knock on heavy throttle transitions.
