[iwk2much]

Hi all. I was looking for input; experience on this issue;

When I first bought my car 2 years ago, changed TB to Tony Mamo + Roto Fab. Drivability with my M6 was much improved compared to the stock TB. Taking off in first gear was smoother and much easier to modulate.

Fast forward many mods later;

Just got back form the shop after installation of a 32% cam, Big Gulp, Kong 103 TB, Kong Ported blower, and 10% lower Pulley / ATI balancer.

I was disappointed with the drivability in first gear, the dead band is a lot larger than what I experienced with the Stock TB, Idling is seems too low, dying at times when coming to a stop, idle is so low that the motor dies before the computer has time to pull the idle back up. The first few degrees of throttle movement bogs the car down as if the mixture is too lean.

Before I contact my shop / tuner with this issue, I just wanted feedback from the folks that have gotten similar mods; how "bad" is your low RPM drivability? What should my expectations be? Never cammed a car before.

Thanks in advance for the input.

[sickss228]

What are the cam specs?

[Z OH 6]

Talk to your tuner, the car should be tuned with those mods. If you're still having issues, your tuner should be able to sort it out.

[LiqTenExp]

The tuner will have to spend way more time on driveability than WOT pulls to get it right. I spent all last year dialing in everything and driveability took 1/2 the time.

You really need to make sure they get the open loop MAF fueling spot on, then lock in the SD tune, then switch to dynamic mode. Once that happens you really can work on trims, timing and other things as it all comes together. With my SD mode the tuner I was working with even added more zones so we could really dial it in and refine the tune.

You will need to have something like the OBD2 AEM WB installed so you can log WB02 during all the part throttle street driving parts described above.

What is your idle set for? Your idle should be at least at 750. Right now 800 is more stable on my build.

[7LitreC5]

I would think that is is cam and/or tune related. I run a NW 103 and a Big Gulp (stock cam). My car drives like stock.

[iwk2much]

Originally Posted by sickss228

What are the cam specs?

231/240, .645"/.635", 113LSA, +32% lobe

Originally Posted by LiqTenExp

The tuner will have to spend way more time on driveability than WOT pulls to get it right. I spent all last year dialing in everything and driveability took 1/2 the time.

You really need to make sure they get the open loop MAF fueling spot on, then lock in the SD tune, then switch to dynamic mode. Once that happens you really can work on trims, timing and other things as it all comes together. With my SD mode the tuner I was working with even added more zones so we could really dial it in and refine the tune.

Thanks for the feedback. I hope my tuner can sort this out. I wonder if there a repository of tunes out there that can be used as a starting point.

[Markoz28]

Originally Posted by iwk2much

231/240, .645"/.635", 113LSA, +32% lobe



Thanks for the feedback. I hope my tuner can sort this out. I wonder if there a repository of tunes out there that can be used as a starting point.

I’m running 103 TB and cam (a bit bigger cam than what you have). You have a tuning issue. When I was having mine tuned, it took about 2-3 revisions to get it dialed in right. Took about 1 week of driving it around and seeing what it would do. Car is solid now.

Make sure your tuner drives it on the street. Drive it around town, turn it off for a couple of minutes, then back on. Drive it hard for a bit. Shut it down and then back on again. See what the car does with some heat in it.

[Markoz28]

For reference, my car idle about 800 RPM and is solid.

[SJFGTO]

I hope your tuner did a thorough STREET and dyno tune. That is essential to address drivability issues. That cam is going to push your HP and torque curves higher, so you are likely to lose some grunt down below/off idle. That said, I think what you have described should be largely cleaned up with additional tuning. Take it back to the shop.

[IneedAZ]

In gear mine is set to idle at 825 and 850 in P/N. What is your timing running at idle?

[iwk2much]

While waiting to bring the car back to the shop to dial out the drivability issue, went to the track for a shakedown in prep for two days at Daytona next week. I wanted to confirm the drivability issue is a not a problem coming out of slow turns;

First couple of laps, engine felt great, slicks fighting harder for traction as heat builds up - definitely more HP - this will be fun!
First hot lap - it was clear the extra 70 HP requires adjusting my marks. I missed some breaking points and had wheel spin when getting on power at my normal marks but lap time was solid. I was excited to spend the rest of the sessions learning and adjusting my marks.

Second lap - timer predicting -.8s, whoa, going to be a good day... until I hit the main straight, RPM climbing in third, then misfire. Shift to fourth, misfire continued. Continued for a couple more laps to absorb what the heck is going on. Misfire occurs at WOT past 4000 RPM in 3rd & 4th gear, doesn't seem to happen at WOT in 2nd gear. After two laps of taking mental notes, the check engine light comes on and start flashing - wtf?. So did a cool down lap - time to go back to the pits. In disbelief and pissed at the prospect of kissing my Daytona entry fee goodbye, a moment of hope;

As I approach pit entry, I noticed the flashing check engine light disappeared. I decided to take another lap. WOT down the straight - no misfire. Hey, I may be OK, next couple of turns, no issues - all right!. That is until I hit the back straight, misfire back, check engine starts flashings again.

Got back to the pits; checked codes, I had two; Misfire Cylinder 8 and Random misfire detected.

Cleared the codes and went back out with my laptop connected to the HPtuner so I can send my tuner the logfile. Same experience, warmup lap fine, as soon as I drove hard and got heat in engine, got the misfire back at WOT. Slowed down, lights stopped flashing, then misfire back after a couple more WOT events. Seems to be heat / load related.

Sorry about the long post; Looking for the gurus to throw out ideas on what I can do to this thing to perhaps cure this problem and save my Daytona experience.

The car had brand new plugs stock NGK 7I plugs installed as part of the build. Just bought a new set of spark plug wires from the dealer to see what that does. I'm just not sure how I can test the results without breaking speeding laws and putting people in danger.

This sucks. Anyone want to take my spot in Daytona on Monday... lol

[radz28]

Hopefully you were scanning and if so, kept your scans to give to the shop. It is more difficult to duplicate some drivability issues than WOT pulls on the dyno; and it might be more difficult for some dynos above others. The more information and data you can use to support what you're finding, the better.

[Markoz28]

Originally Posted by iwk2much

While waiting to bring the car back to the shop to dial out the drivability issue, went to the track for a shakedown in prep for two days at Daytona next week. I wanted to confirm the drivability issue is a not a problem coming out of slow turns;

First couple of laps, engine felt great, slicks fighting harder for traction as heat builds up - definitely more HP - this will be fun!
First hot lap - it was clear the extra 70 HP requires adjusting my marks. I missed some breaking points and had wheel spin when getting on power at my normal marks but lap time was solid. I was excited to spend the rest of the sessions learning and adjusting my marks.

Second lap - timer predicting -.8s, whoa, going to be a good day... until I hit the main straight, RPM climbing in third, then misfire. Shift to fourth, misfire continued. Continued for a couple more laps to absorb what the heck is going on. Misfire occurs at WOT past 4000 RPM in 3rd & 4th gear, doesn't seem to happen at WOT in 2nd gear. After two laps of taking mental notes, the check engine light comes on and start flashing - wtf?. So did a cool down lap - time to go back to the pits. In disbelief and pissed at the prospect of kissing my Daytona entry fee goodbye, a moment of hope;

As I approach pit entry, I noticed the flashing check engine light disappeared. I decided to take another lap. WOT down the straight - no misfire. Hey, I may be OK, next couple of turns, no issues - all right!. That is until I hit the back straight, misfire back, check engine starts flashings again.

Got back to the pits; checked codes, I had two; Misfire Cylinder 8 and Random misfire detected.

Cleared the codes and went back out with my laptop connected to the HPtuner so I can send my tuner the logfile. Same experience, warmup lap fine, as soon as I drove hard and got heat in engine, got the misfire back at WOT. Slowed down, lights stopped flashing, then misfire back after a couple more WOT events. Seems to be heat / load related.

Sorry about the long post; Looking for the gurus to throw out ideas on what I can do to this thing to perhaps cure this problem and save my Daytona experience.

The car had brand new plugs stock NGK 7I plugs installed as part of the build. Just bought a new set of spark plug wires from the dealer to see what that does. I'm just not sure how I can test the results without breaking speeding laws and putting people in danger.

This sucks. Anyone want to take my spot in Daytona on Monday... lol

Tuning issue for sure. Take back to tuner or find another. Personally I’ll be sticking with Jannetty from here on. Best experience so far. Real easy
To work with and car is perfect.

[iwk2much]

Originally Posted by Markoz28

Tuning issue for sure. Take back to tuner or find another. Personally I’ll be sticking with Jannetty from here on. Best experience so far. Real easy
To work with and car is perfect.

You ship your car to them?