Torque v BHP - Full power just feels wrong..!

[DaveT]

Hi Guys,

OK to start off with engine is an Audi 5 cylinder 10v turbo lump, running MS2 v3 in fuel only mode. Boost is set to factory spec of +0.6 Bar / 8.5 PSI.

Car start and runs well, it just doesn't pull well in the higher gears. Takes off like a scolded cat in first and second, and will hit the rev limiter very easily, third pulls ok, fourth and fifth, well it just really doesn't want to go. If I accelerate slowly like half throttle it will accelerate from say 60 to 80 quite nicely, holding about 0.2 / 0.3 bar of boost. If I floor the throttle it boost shoots up to 0.6 bar but it just doesn't accelerate any quicker. I don't know how to describe it, it just feels like its being held back. If I can get it over about 4200 rpm in fourth and fifth it appears to pick up a bit but it may just be the placebo affect.

I'm not sure if I've done anything wrong, AFRs all look quite nice, should I try more or less fuel at higher boost or am I missing something?

Any advice greatly recieved.

Many thanks
Dave

P.S. I'd post a log and msq but I've left my laptop at work, I'll get it next week if it helps...

[Matt Cramer]

P.S. I'd post a log and msq but I've left my laptop at work, I'll get it next week if it helps...

Please do; this sounds more like a tuning issue than anything else.

[DaveT]

Thanks for your reply, here is a copy of the current MSQ file.
As for the logs, what type of thing would be best, a full power run through all the gears??

Many thanks

Dave

[Matt Cramer]

Yes, that would be a good starting point.

[DaveT]

Hi Matt,

Here you go, I did 2 logs first one is full power 1st through to 5th gear. Second log is 3rd gear pull. I think the 3rd gear log probably show the issue the best, boost remains roughly the same but acceleration suddenly increases shortly after 4000 rpm...

If it helps here is a link to the turbo charger i'm using with its map...

http://www.034motorsport.com/turbocharg ... p-321.html

Many thanks

Dave

[kjones6039]

I am curious about the RPM spiking to zero at 1656.703 in the 3rd gear log.

I will be interested in what Matt has to say about that.

Ken

[Matt Cramer]

Not much other than that you may need to clean up the tach signal just a little; that would have given a small misfire when the RPM spiked to zero. Nothing obviously wrong with the log.

[WASyL]

I just went thru config, and that IAT-Based Fuel Correction is huge, You add alot of fuel when IAT gets hot, that might flood engine too much as i recon.

best regards

[DaveT]

Hi Guys, thanks for your replys.

Matt: Yes it did have a little missfire, how would i go about cleaning up the tach signal?

Wasyl: the IAT correction has been set like that because the IAT sensor suffers really badly from heat soak, so if I park up for 15 mins then try to drive away its almost impossable to drive. Its on my 'to do' list, relocate the IAT sensor!


If theoretically the fueling is right, and timing is from original ECU, is there any other reason that I'd have plenty of boost but not much power?

Many thanks

Dave

[WASyL]

Then Your ECM mess with ignition

best reagrds

[Matt Cramer]

How exactly are you getting a tach signal right now?

[DaveT]

Hi Matt,

Currently its getting the tach signal from the distributor. To be honest I'm looking into utilising the original sensors and moving timing control accross to MS so I'm gonna guess that would sort the RPM spike...

Many thanks

Dave