PDA

View Full Version : Crisper throttle response with tuning possible?



2000ssnb
March 5th, 2005, 08:38 AM
I am happy with my tuning so far for the most part.
However, I am wondering if there are specific tuning
steps I can take to make throttle response crisper,
both from idle and when at part throttle.
Presently I have the high octane spark map and the VE table set to that of a 2002 Z06 since I have the LS6 intake and LS6 heads etc.
It runs well but, of course, I want more....

Any suggestions? Thanks,

Gert

Ira
March 5th, 2005, 10:16 AM
I have wondered this also and I'd log timing, O2 and throttle position while you add sudden throttle at various RPM and load conditions. Also make sure you try it with various amounts of additional throttle. not just 10% to 100%, but also smallr changes like 10% to 40% and 20% to 50%. The more information you have, the more likely you are to be able to infer what's happening and what might improve throttle response. It's exactly why you'd like to have access to a load cell dyno.

I think what you're looking for is the very short term reaction of the timing and O2 readings to throttle movement. You're probably best doing this in a higher gear going up a steep hill as I think you're better off if the RPM doesn't change very much over eash test point.

I was at an engine builders one day and he was showing off his engine dyno software and it was, as an example, able to hold a series of RPM settings and step the throttle in 10% increments for each one. Recording timing, air fuel ratio and torque over the full test. A perfect setup for testing throttle response.

2000ssnb
March 6th, 2005, 04:48 AM
I suppose it would be useful to know what to look for -
that is what should be the numbers for spark, a/f, etc.
during throttle changes,
and then compare to what one gets actually.
Once the differences are known, tuning can probably
be used to reduce these differences.
Gert

Ira
March 6th, 2005, 05:03 AM
Well you should expect 2 things to happen, the mixture to get slightly richer or at least not leaner and the timing to retard, the issue in improving throttle response is going to how fast those changes occur and how much of a change there is. I wish I could tell you what to look for, but I can't. I'd sure start by looking for any hint of leanness on tip-in as that would be an obvious problem.

Ira