A little help please...

[johnrw]

Hi been running Versatuner for about 8 months on 2008 3 MPS, very happy with the results car was standard apart from modified air box (all bottom cut out and K&N panel filter) was running Base 93US/98EU octane and very happy with it.

This year I decided to modify a little, I added 3" Cat back exhaust and Autotech HPFP internals and ran the Base high load tune. Checked MAF Cal and all was well (about +/- 4% LTFT) very impressed very surprised at the amount of power increase.

Now last week I added a Corksport SRI and TIP then spent a while doing the MAF Cal until I am now happy with it, the problem is that the car now feels much slower than with the standard intake, checked all pipework several times can't find any problems or boost leaks, with standard intake and base high load tune the car pulled really hard in 3rd with quite a bit of lost traction and torque steer

Now with the corksport power is there and nice and smooth but nothing like it was before and no loss of traction at all.

Here is a log taken tonight about 7 degrees outside and taken from 2000rpm to redline in third, would someone cast there eyes over it and see what you think please?

Thanks,
John

[mituc]

Can you also post your tune? I can see that the MAF g/s values go up to about 250-260g/s which is good, and at the same time the AFRs stay around 0.74 lambda (10.88AFR) which makes me think that the MAF cal is about where it should be (depending on what you command in your tune).

You can also check the Share your MAF CAL thread (http://www.versatune.net/forum/viewtopic.php?f=12&t=231) because there are some pretty good CS MAF CALs there. Download one and see how much off you are, if you're off by less than like 5% you should be fine I guess, since such small differences may come from the fuel you use (some have additives richer in oxygen, say, embedded in ethanol or other compounds).

Also, next time you take a look please make sure that you log the following:
1. absolute load;
2. relative throttle position;
3. actual AFR or actual lambda;
4. RPM;
5. MAP;
6. timing advance;
7. Knock Retard;
8. Mass Air Flow;
9. WGDC;
### until here these are all present in your log
10. Boosted air temperature;
11. fuel rail pressure;
12. vehicle speed.

You can remove the Accelerator pedal position from the logs since you have the relative throttle position which is more important (this tells you how much the actual throttle plate is open, while APP tells you how deep into the floor you press the pedal).
I also added the vehicle speed for at least two reasons I can think of:
- we need to know what gear are you in since the load targets may differ from gear to gear;
- you will later be able to tell exactly the differences at full load between the tunes by measuring the time the car needs to go from one speed value to another (say, 50mph/80Kmph to 80mph/120kmph, or 60mph/96kmph to 100mph/160Kmph), and not just say "it feels faster/slower", but actually see if it really is.

[johnrw]

Hi Mituc,
Thanks for replying.
The tune is the Base High load tune un-modified (attached) I am an electronics engineer by trade and spent more than 10 years repairing the hardware side of ECU's I played around with tuning in the early days of ECU when they were very much simpler but am out of touch with the modern ones. Here is a log from today if you do not mind having a look at it for me.
As for the MAF cal I did get the CS one from the forum and mine is quite similar.

Thanks,
John

[mituc]

Btw, do you also have a log you taken before you added the intake, exhaust and HPFP internals?
And do not forget to take another log with all the parameters specified above...

[johnrw]

I am afraid I have not got a log from before the intake was fitted, that's part of the problem, in the previous post zip file is a new log with all the parameters you mentioned, starts at 2000rpm in 3rd to redline then a brief run 4th.

John

[mituc]

Ok, I checked your tune and there's no explanation why your car is slower with the new high load tune unless the MAF cal on the old tune was significantly leaner (assuming that the current MAF cal is spot on), which made the calculated load to be smaller, so in reality by targeting the load in the tune the actual load was higher.
Anything else, load, boost, timing, suggests that the new tune should make your car faster.

[johnrw]

Thanks for your help. Wanted to check that everything looked reasonable before I do more investigation.


John

[mituc]

I also checked the performance log you added into that zip file and for a 96-160Kmph (60-100mph) for under 7 seconds (even if you go start in 3rd gear) it's reasonable on pump gas. Maybe with the previous tune you were doing some pulls in significantly colder weather? The log I'm looking at seems to be taken in 4-5 - maximum 7C weather.

You can probably use one more degree of timing up top (above 6k rpm) and eventually target load of about 1.95 up until 5.5k rpm and decrease gradually to what you are now at 6500rpm.
You can also contact an e-tuner, Stratified Auto is doing Versatuner e-tunes and I can vouch for them.

[johnrw]

Thanks for the feedback, today I fitted a K&N filter to the corksport tip (I bought the corksport used and the filter was in poor condition) the car is more powerful but the MAF Cal is about out (lean I am amazed that the filter makes such a difference). I am going to drive steadily over the weekend and do the MAF cal again and then contact Stratified.

Yes, the last log was around 7 degrees temp and it was a bit colder with the previous intake, probably 2 degrees. So I think the extra power was down to temperature and also lean with the old intake.

Thanks so much for your help I really appreciate it, good to know there are genuine helpful people out there.

Thanks,
John