i have a 2005 z51. Looking to get better throttle respone. Corsa exhaust cold air intake.....thats it not trying to change exhaust bc i finally have one that does not have a drone when i drive it. Any ideas..

 

A lot of people on here will tell you to get gears. They are expensive (to me) but they may do it for you.

If you agree with me then your best bet would be to get your intake and throttle body ported along with a good tune. You will notice a difference.

 

A good tuner will make it happen for you. Anything else just adds to the fun.

 

If the tip in response seems slow, a tune can improve it.
Are you an A4? Raising the A4 shift points can really help too.

 

Porting the throttle body should help.

Seth

 

definately port the throttle body and intake manifold. Your throttle response will improve greatly. But make sure you get a proper tune. Without a tune, gains will be marginal.

I believe Jeremy Formato of Fasterproms.net has a porting special going on right now. Be sure to check him out. He can hook you up with a mail order tune as well if your interested. JJFormato is his CF name.

 

I'm running stock with just a Vararam. I just had my own tb "ported" and didn't get a tune (said it isn't really necessary but I'm sure it'll help). A small mod and it was only around $149.00, so I figured if it will help with the response, then why not. I'm happy so far.

 

Heh... I have complained about the 05's for years. Finally this year HP tuners put out the fix in their latest beta.

I tried to tune better throttle response for years and it was futile until we got the throttle rate table. Our 05's are tuned sluggish from the factory.

Read more here. You will need to find a tuner with the latest 2.23 beta. It's a nice difference!


http://www.hptuners.com/forum/showth...+response+beta

 

Ported throttle body increased response on my 06, even without a tune. Mine was ported by VMax Motorsports. They have a 149.95 turn around mailing program in conjunction with Norris Motorsports. They send you a ported unit and then you send them yours after installation. No downtime for your car. Check mikenorrismotorsports.com for further information.

 

Only 05's have the sluggish response from the factory, the 06's on have that table set for a quick throttle opening rate.

 

The 07's had a sluggish or delayed rev at the tap of the pedal. I hated it
and I can still hear that air rush sound before the engine revs. Is that what we are talking about here. On mine the ported TB and tune fixed it.
I told Jeremy formato I hate that delay at the tap of the pedal. He fixed it
by replacing the TB with a ported one and tuned it out. Since then there has been no delay, hesitation or lack of throttle reving at the tap of the pedal. Its gone and I know others hate it as well. I hope GM did something in 08 or 09 bucause in 07 it was still a problem.

 

That's mine but I sent directly to VMax and got it back quicker than doing the core.

 

I cant believe GM would ship cars out that would have the problem.

 

Yes this sluggish response on the tap of the pedal is exactly what I'm talking about. It's a killer if you like to heel and toe downshift like I like to do. Makes it nigh impossible to do and that's no good for road course use. I noticed it the first time I drove my C6 from my C5, the C5 was always snappy.

EFI Live had that throttle rate table for a while now. Pro tuners knew to adjust it on cars that had the factory sluggish rate settings to make the car feel snappy. It's new from January in HP Tuners.


To prove how long and hard I fought this sluggish throttle, look here!

http://www.hptuners.com/forum/showth...response+table

I was trying since 9/07. I knew something was wrong, and tried a lot of things.

Here is what that throttle rate table does - courtesy of Chris at HP Tuners:

the table is called "Throttle Area Increase Rate" and the short help says "This table controls the rate of increase of desired throttle area, set to maximum to disable."

The value is the amount the desired throttle area (the effective area opened by the throttle blade) is allowed to *increase* per "tick" of time within the PCM.

eg. In the ECM drive by wire works roughly like this:
1. Pedal position is measured
2. Pedal position is translated into a requested throttle area % (Driver Demand Throttle)
3. This is arbitrated against all the other allowed throttle requestors, like Cruise Control, Idle and various forms of torque management and failure modes.
4. the lowest is chosen (if nothing else is active then this will be the Driver Demand Throttle)
5. At this point the ECM knows where the throttle wants to move to and also it's current position. It just has to decide how fast to move the throttle from it's current position to the desired position. This is where this table comes in.
6. If the throttle area is *increasing* this table is looked at and the throttle is moved an amount based on the current position and the table value. If it's 1% then it won't move much this "tick". If it's 100% it will probably move directly to the new position (or as fast as is mechanically possible).
7. The amount of time it takes for the throttle to increase to the new position depends on this table. Small numbers take longer, 100% is the fastest.

So it's a ramp rate

The intent of this table is to make the throttle move slower in low speed driving situations or prevent unwanted driveability issues on smaller engined vehicles in higher gears/low RPM.

This is why usually if calibrated this table will have numbers like 1% or 5% at the lower RPM or pedal positions in low gears. Unfortunately for higher powered vehicles it acts as an unwanted traction control. It also removes that nice crisp response you get in a blown car when you snap the throttle at low RPM.

 

. . . and you think with the last years run (LS2, etc.), they'd have all of this worked out. I also thought about the FAST (Spin's mod) but was told unless I did the performance mods (cam, headers, etc.) like alot of you guys have, for me not to do it. So I at least did the quick and very affordable tb porting to hopefully, at least, take advantage of this.

 

You are in PA, Jeremy Formato is in Gettysburg. PM me and I will get you his # he is only going to be here till next weekend. He has several fully ported LS2 intakes and while you wait he can port out your throttle body, PLUS for 300.00 do a street tune.....for for 480.00 do a dyno tune. You cannot beat that price! I just got mine done yesterday and I promise you for the money and the throttle response difference nothing can compair. And all I have done is a Jeremy ported LS2 intake/TB, vararam, and bassani cat back.

 

I would say you have the philosophy worked out. I now would take care of idle / throttle response issues prior to any other installations. I love the FAST HEADERS & CAM for getting the horsepower & Torque numbers. I have HP tuners but its the last thing I got and also someone else had to solve the throttle response issues. I dont have the patience that JOE. G has and he spent much time working it out. I now see all those tables just with the idle section and starting to learn them.

 

perfect sounds good how do i get in contact with jeremy

 

He is at keiths pitstop in Gettysburg. His cell # is 813-495-8778. Give him a call , he may fit you in. You will love the results.

 

thanks again calling him now.