Best in the business

[LS ROB]

Ok guys. It looks like I'm going to have to have someone who really knows their stuff take a swing at my tune. I've spent countless hours over the span of a year researching and band aid tuning to get this hiccup out of my cruise/light load area that roughly starts around 1500rpm. I have spent more in gas than what a tune would have cost me. I want this thing to drive smooth. I know if guys can get stage 4 cams to drive stock-ish, then surely a stage 2 can be made to do the same. With that being said, id like to get a few names thrown in the hat so that I can make some calls and hit some websites. Who is the best you know?

[Ben Charles]

I assume a manual??

[LS ROB]

Yes Sir, its a swap vehicle. Ls7 t56 magnum. Stage 2 TSP cam. 234/246 .635/.635 115+3. MSD Intake, Long tube headers, Stock ls7 heads that was reworked and milled .020 by American Heritage Performance. NW 102. NA car on 93. Just installed some bigger injectors today so the tune still needs tweaked. Couldn't upload the log since the file was too big, but I did attach the tune. Man this thing is killing me. I've changed things in the cal. that has been suggested by guys on the forum and none seem to help. So, I'm curious to know who/where to go. I wouldn't care if someone ONLY changed whatever it is that makes this thing jerk; as long as it doesn't cause issues elsewhere. I've read where disabling spark smoothing will "fix it" but take off drivability gets rough. It seems if you fix one thing, it throws something else off. I want to run it in Closed Loop.
new injector vve tune 1.1.hpt

[GHuggins]

Did disabling spark smoothing fix it? If it did then take off's easy enough.

[LS ROB]

Did disabling spark smoothing fix it? If it did then take off's easy enough.

Honestly, I didn't even try it since the thread had several folks concur that take off suffers. I can give it a go tomorrow evening and let you know though.

[GHuggins]

Also - only for testing purposes - put it into open loop and drive it to see if the problem is gone. Quick separate test.

[LS ROB]

Also - only for testing purposes - put it into open loop and drive it to see if the problem is gone. Quick separate test.

I can try this as well but i'd really like to run it in closed loop if possible.

[GHuggins]

It's only a test for eliminating a possible something else. Shouldn't be causing your issue. But easy enough to test for.

[LS ROB]

It's only a test for eliminating a possible something else. Shouldn't be causing your issue. But easy enough to test for.

I see. I'll start with the spark smoothing test first then i'll try to put it in open loop if i have time. I have class tomorrow so my after work / before class, time window is small until friday.

[morepowerjoe]

Are you talking about jerking in gear when at a stop?

[grubinski]

I had a he** of a time getting my Miata with cammed LS3 to drive smooth in those conditions. I finally have it running very smooth. Look for my thread in this subforum titled "Driveability Tune Attached". I give some explanation as to what I found helpful to tweak to smooth it out.

https://forum.hptuners.com/showthrea...+Tune+Attached

[Alvin]

I'll be a honest.. A someone that does this 9-5.. That cam is on the edge, likely over from what will drive good in closed loop. No matter what you do the stock o2's are going to drive that thing into running bad.

There are exceptions.. And some cars that will be ok but that much overlap, plug long tubes and colder sensors, just = trouble.

That should be a easy setup to drive smooth though. I would have skipped the throttle body. low HP/$ and can be just tuning trouble.

[blindsquirrel]

And I also want stump-pulling torque at 800 RPM without losing any at 8000, at least 30 MPG, a pony, cake for breakfast every morning, and a billion dollars.

[GHuggins]

The problem he's been having is it's going into idle mode while cruising down the road. This is causing timing to be yanked resulting in the "perceived" bucking.

I honestly believe the best tuners in the business are already on this forum except for one up north. This is just seeing all the tunes that I personally go in behind on or people I talk to. I could see the throttle body being so closed that it would exhasborate the issue, but I've also never seen one other car do what his is doing before without something else being the problem. I know from post he's tried a different pedal, injectors and several other tune related things that shouldn't normally need to be done. I think he's even tried maxing out etc scaler and adjusting the baro tables to shift it out of this zone - don't know how aggressively, but didn't work.

Don't think he's expecting too much, just got a really odd ball issue - at least from post he's made...

[blindsquirrel]

What about the Dynamic settings? I have never seen a file with disable/reenable only 1 RPM apart like that. I can't imagine anything good happening if it happens to be right at that specific engine speed.

[LS ROB]

What about the Dynamic settings? I have never seen a file with disable/reenable only 1 RPM apart like that. I can't imagine anything good happening if it happens to be right at that specific engine speed.

Changed those settings more recently as i wanted the MAF to take over right around where my cam comes into play. I set it up like that because i thought it was more of a on/off switch-like setting. I can change the spread a little more and see if that makes a difference but i doubt it will, as the issue was present when i had 100 rpm difference between them.

As for spark smoothing, it didn't help. Attached is the current tune and a short drive log.
spark smoothing disabled.hpl
new injector vve tune 1.1 disable spark smoothing.hpt

[LS ROB]

I had a he** of a time getting my Miata with cammed LS3 to drive smooth in those conditions. I finally have it running very smooth. Look for my thread in this subforum titled "Driveability Tune Attached". I give some explanation as to what I found helpful to tweak to smooth it out.

https://forum.hptuners.com/showthrea...+Tune+Attached

Thanks. I'll read up on that.

[LS ROB]

I'll be a honest.. A someone that does this 9-5.. That cam is on the edge, likely over from what will drive good in closed loop. No matter what you do the stock o2's are going to drive that thing into running bad.

There are exceptions.. And some cars that will be ok but that much overlap, plug long tubes and colder sensors, just = trouble.

That should be a easy setup to drive smooth though. I would have skipped the throttle body. low HP/$ and can be just tuning trouble.

I thought it shouldn't be difficult to tune as well. The engine was built from scratch, so i picked up the hot ticket at the time and grabbed the NW102.

[LS ROB]

I did notice from the log i took today that the FTC was 0. When cylinder airmass hits .162 it jumps to 7. Possible bad ecm?


EDIT*** does FTC correlate to the Zones in the VVE table? If not then i'm wrong about that.

[LS ROB]

Are you talking about jerking in gear when at a stop?

Its while i'm cruising in the light load area that roughly starts around 1500rpm.