L98 Mafless Tune - Talk About Dssapointing

[doccortex]

Finally, getting my car properly tuned.

When I had my CAM. OTR, exhaust, etc, fitted, it went to LSX Tuning in Marrickville.

Picked up the car - what a dissapointment, the toque was evident, but driving the car was a nightmare, stalled in traffic, pig rooted, etc, etc.

Took it back twice, and no better. His words, just keep bringing it back. Mate, I live miles from there, why the mechanic even used him is beyond me. I gave up in frustration.

Took it to Hi-Comp in Minchinbury, fixed the pigroot, straight away, smoothed out the idle, did what should have been done in the first place. The stalling, ECU shows P0601 ( ECU Memory - ROM ). Not good. Really cheesed, as this only started after the MODS. Waiting for a callback, VCM looking at the mapping, and if can be fixed, then will reflash for free.

Just shows you, theres TUNERS, and theres tuners. Pointless trying to claim anything from LSX, they couldn't care care less.

Chow
Doc

 

[social]

Did you achieve the significant gains you were expecting after the re-tune? was there evidently more power/ torque when done properly?

 

[doccortex]

Did you achieve the significant gains you were expecting after the re-tune? was there evidently more power/ torque when done properly?

I was always happy with the torque, it was the driveability that was the question. Heaps of wheelspin, 1-2-3 gears. The 275's and lowering, certainly have helped in that area, so much more rubber . But the original tune was just awefull!
Imagine in traffic, to get the car moving, you had to really hit the pedal, and when it did, it took off like a rocket - not good, when theres a car 10 feet in front of you

Cheers

Doc

 

[doccortex]

Did you achieve the significant gains you were expecting after the re-tune? was there evidently more power/ torque when done properly?

I was always happy with the torque, it was the driveability that was the question. Heaps of wheelspin, 1-2-3 gears. The 275's and lowering, certainly have helped in that area, so much more rubber . But the original tune was just awefull!
Imagine in traffic, to get the car moving, you had to really hit the pedal, and when it did, it took off like a rocket - not good, when theres a car 10 feet in front of you

Cheers

Doc

 

[doccortex]

sorry - reposted by mistake

 

[yxyx64]

I was always happy with the torque, it was the driveability that was the question. Heaps of wheelspin, 1-2-3 gears. The 275's and lowering, certainly have helped in that area, so much more rubber . But the original tune was just awefull!
Imagine in traffic, to get the car moving, you had to really hit the pedal, and when it did, it took off like a rocket - not good, when theres a car 10 feet in front of you

Cheers

Doc

a common mistake is to think wider tyres put more rubber on the road. Wider tyres change the SHAPE of the contact patch but the only way to increase the SIZE of the contact patch (square mm) is to change tyre pressure (unless you have changed the weight of your car). The size (area) of the contact patch does not depend upon the width of your tyre.

 

[doccortex]

a common mistake is to think wider tyres put more rubber on the road. Wider tyres change the SHAPE of the contact patch but the only way to increase the SIZE of the contact patch (square mm) is to change tyre pressure (unless you have changed the weight of your car). The size (area) of the contact patch does not depend upon the width of your tyre.

Hmmm, the dynamics of the car have certainly changed in some way. Yes, still some wheel spin, but nothing near what was evident before the new rubber. Perhaps due to the lower centre of gravity - maybe ?

 

[yxyx64]

Hmmm, the dynamics of the car have certainly changed in some way. Yes, still some wheel spin, but nothing near what was evident before the new rubber. Perhaps due to the lower centre of gravity - maybe ?

do not get me wrong - different widths, tread patterns and profiles have a HUGE impact on car feel and turn/tracking. Contact patch shape also has a huge impact. Fresh rubber is usually stickier, wider tyres distort sidewalls less when rotating to apply the contact patch as the contact is wider across the car but narrower along the car.....but the actual contact area (in square mm) can only change with tyre pressure for the same weight.

 

[Munz]

Cam specs?
Auto or manual?

 

[doccortex]

Manual - 230

No luck yet with the code errors, hasn't happened since, but, is always in heavy traffic, when idleing for extended periods of time. Trying to stay away from anywhere with heavy, crawling traffic - in Sydney, thats a real task.

Tuner sent the mapped file off to VCM - they can't find any errors, leaving the ECU as the prime suspect. Now, even more bad news. A new ECU, around $350 best I have seen from EBay, I can't just swap it out and reflash. It has to be coded by GMH for that particular engine number, then, I can't have the tuner dump the flash, it has to be totally dyno'd again! - what the hell! - all up at least $2 grand there. Just dosn't make sense!

Ciao
Doc