Another SD Convert
03-01-2009, 08:58 AM
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Another SD Convert While I've always been a MAF fan for driveability, it does have limitations with a boosted car. I've tried twice to run SD with pretty poor results. So today I took my car out to see my tuner to give it another shot.
After spending 2 hrs figuring out we had 2 of the newer style MAP sensors that didn't work right....now I know why I had so much trouble before....we made a jumper pigtail up for an old school 2 BAR MAP (one of the big ones, P/N 12247571) and viola, the car popped right off.
Within 10 minutes that car was starting & idling better than it has in quite some time. The instructions that come with HP T now are pretty good for getting started & we pasted my existing VE table into the bottom of the new 2 BAR table. Other than a lean tip-in issue when you pull away from a stop sign it drives as good as it did with the MAF. (to 1/2 throttle anyway, no WOT stuff yet)
So now I'll get the harness for HP Tuners that plugs my wide band into it so we can get this thing dialed in & ready for a trip to the rollers @ Turbo Tech.
After spending 2 hrs figuring out we had 2 of the newer style MAP sensors that didn't work right....now I know why I had so much trouble before....we made a jumper pigtail up for an old school 2 BAR MAP (one of the big ones, P/N 12247571) and viola, the car popped right off.
Within 10 minutes that car was starting & idling better than it has in quite some time. The instructions that come with HP T now are pretty good for getting started & we pasted my existing VE table into the bottom of the new 2 BAR table. Other than a lean tip-in issue when you pull away from a stop sign it drives as good as it did with the MAF. (to 1/2 throttle anyway, no WOT stuff yet)
So now I'll get the harness for HP Tuners that plugs my wide band into it so we can get this thing dialed in & ready for a trip to the rollers @ Turbo Tech.
03-22-2009, 09:21 AM
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So yesterday after being out of town for 2 weeks I fired the car up to pull it out of the garage - spring cleaning time - & the car was surging pretty bad. It's the first time it's started since I drove it home after converting to SD.
So for some reason unknown to me, I pulled the IAT sensor wire & the idle cleaned up. To make sure this wasn't a fluke I lete it sit for a couple hours to cool back down & started it again without the IAT plugged in & fired up & idled perfectly without touching the gas.
I haven't gone in to look at any tables to figure out what to tweak to fix this, but I thought it was worth sharing what might be 1 solution for surging idles at startup on cars with big cams & FI. I will post up when we figure it out.
So for some reason unknown to me, I pulled the IAT sensor wire & the idle cleaned up. To make sure this wasn't a fluke I lete it sit for a couple hours to cool back down & started it again without the IAT plugged in & fired up & idled perfectly without touching the gas.
I haven't gone in to look at any tables to figure out what to tweak to fix this, but I thought it was worth sharing what might be 1 solution for surging idles at startup on cars with big cams & FI. I will post up when we figure it out.
03-22-2009, 03:45 PM
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I think you missed my point - I wasn't aware the IAT had that much of an affect on the idle! And since I JUST converted to SD, I think it's obvious that I need to tweak some tables. And now I have a new place to look to fix the ellusive surging some cars have....
03-23-2009, 05:57 AM
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My tuner says....
It means it needs fuel. When you pull the IAT it defaults to -40* and pours the fuel to it.
Learn something new everyday. Sounds like an easy way for people to see if that's what their surging problem is?
It means it needs fuel. When you pull the IAT it defaults to -40* and pours the fuel to it.
Learn something new everyday. Sounds like an easy way for people to see if that's what their surging problem is?
03-23-2009, 08:53 PM
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Yep, it's a new learning curve for me. It tells me how far off I made some things trying to tweak the MAF tune. It was idling OK after I played with the Inj Startup table with the MAF tune. Evidently I was masking something else. We'll get it.....
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03-27-2009, 10:48 AM
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We made some good progress last nite on my SD tune!
It took us a while to sort out how to make the WB O2 display correctly (WB AFR, Commanded AFR & AFR Error....the key to SD tuning) but once he got that figured out the tune came around quickly. The car idles fine, 'normal driving' is MUCH improved, and it feels like it has more power at WOT than it ever did. The car literally almost flies at 120 in 3rd gear.
To anyone that is wondering whether to go SD on an FI car, do it! I held off for quite some time because I wasn't convinced....well, I AM now! Not only do you get more power, but tuning is a lot easier with AFR Error. It gives you the correction numbers for all the cells.
800rwhp & 9s look possible now!
Thanks to Bill @ HPTuner for getting me going & to Ellis for staying up late to tune the car!!!
It took us a while to sort out how to make the WB O2 display correctly (WB AFR, Commanded AFR & AFR Error....the key to SD tuning) but once he got that figured out the tune came around quickly. The car idles fine, 'normal driving' is MUCH improved, and it feels like it has more power at WOT than it ever did. The car literally almost flies at 120 in 3rd gear.
To anyone that is wondering whether to go SD on an FI car, do it! I held off for quite some time because I wasn't convinced....well, I AM now! Not only do you get more power, but tuning is a lot easier with AFR Error. It gives you the correction numbers for all the cells.
800rwhp & 9s look possible now!
Thanks to Bill @ HPTuner for getting me going & to Ellis for staying up late to tune the car!!!
03-29-2009, 09:31 AM
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I spent some time yesterday on the start-up & idle and filling in the VE table based on the driving I've done so far. Not only does the car lift the front end & top the shocks out at 120, now it starts & idles perfectly (standing outside the car turning the key - fires right up, AFR = 14.5).
SD makes tuning SO much easier....I apologise, you guys were right, SD is THE way to go! I can't wait to put it on the rollers & see the new numbers after we get this finished. My Butt-O-Meter says there's a lot more than the 704 I made with the initial MAF tune.
Here's the VE table so far....certainly not done, we still need to log some more, especially the top end.
SD makes tuning SO much easier....I apologise, you guys were right, SD is THE way to go! I can't wait to put it on the rollers & see the new numbers after we get this finished. My Butt-O-Meter says there's a lot more than the 704 I made with the initial MAF tune.
Here's the VE table so far....certainly not done, we still need to log some more, especially the top end.