SRT Engineers admit car has hesitation - can Diablo fix it?

[slip]

During the last SRT Engineers chat, the SRT Engineers said this about the car's hesitation.

http://www.lxforums.com/board/showpost. ... stcount=87


Question
Why does this vehicle have so much hesitation when you step on the gas pedal? seems like it winds up and then shoots out. It feels like it builds up power, then releases it.

SRT Engineer's Answer
Your feeling what the government has forced us to do for emissions regulations. We don't like it either! Its related to the pedal/throttle relationship and combustion stability.

Can Diablo reverse engineer out this "pedal/throttle relationship and combustion stability" so we have better throttle response?

[JackFlash]

I installed an 85mm throttle body on my R/T and it eliminated this problem altogether. The throttle response is smooth at all rpm's now with no hesitation.

[mikel]

Have you tried the Predator tunes?

Throttle response is increased quite a bit, and can be increased more in a custom tune if desired.

[slip]

Have you tried the Predator tunes?

Throttle response is increased quite a bit, and can be increased more in a custom tune if desired.

Sure. Running 91 oct tune. Is the Diablo throttle response adjustment the same as adjusting tip-in?

There seems to be several different definitions of throttle hesitation.

My biggest beaf with our car is the RPM bogging during moderate acceleration.

Here is a log of the bogging. As I am increasing pedal pressure to moderatly accelerate, the RPMs decrease when they should be increasing.
This creates a bogging/hesitation. The green RPM line makes a U-turn south when it should be headed north with the red Pdl Percent line.

This is with the Predator 91 tune. The bogging occurs less often with the Predator, but the Predator has not fixed it, as shown in this log.

I don't know if the bogging in this log is the same thing the SRT Engineers were referring to. If not, then our cars have more than one problem with bogging/hesitation.

[broadfca]

I installed an 85mm throttle body on my R/T and it eliminated this problem altogether. The throttle response is smooth at all rpm's now with no hesitation.

Hi JackFlash, I am considering getting a 85mm TB for my car. Can you tell me what all you had to do. Did you have to take it to the dealer? What brand did you get? Have you discovered any down side from making the change?

Thanks

[Cruisin1966]

I installed an 85mm throttle body on my R/T and it eliminated this problem altogether. The throttle response is smooth at all rpm's now with no hesitation.

Hi JackFlash, I am considering getting a 85mm TB for my car. Can you tell me what all you had to do. Did you have to take it to the dealer? What brand did you get? Have you discovered any down side from making the change?

Thanks

We just installed an Arrington 85 mm TB in my buddy's 09 SuperBee last night. Can't imagine it's much different than just pulling off the air intake tube, unbolting the old TB, and bolting in the new TB and re-installing the intake tube.

[TRippgoodman]

I have a 2009 Challenger SRT8 That I just installed a Vortech Supercharger kit on. It was programed with a Predator #VR7135 Serial#249872 that came with the kit. The problem is that the ESP throttles back almost everytime you give it the gas. Vortech tells me that I should contact Diablo to see if they can turn off the ESP. Any help is appreciated. Trippgoodman

I would not want to turn off the ESP or the ABS permanently, But to make a clean run down the drag strip to see what the car could do would be nice option once or twice a year. Please help. Thanks, Trippgoodman

[mikel]

Do you not have a quick adjust parameter to disable ESP?

Thats not really something we recommend for daily driving anyhow, as it disables ABS as well.

[Mike_Levy]

We just installed an Arrington 85 mm TB in my buddy's 09 SuperBee last night. Can't imagine it's much different than just pulling off the air intake tube, unbolting the old TB, and bolting in the new TB and re-installing the intake tube.

You're supposed to have the blade calibrated with the StarScan. Alot of us haven't bothered though, myself included.

[JackFlash]

I installed an 85mm throttle body on my R/T and it eliminated this problem altogether. The throttle response is smooth at all rpm's now with no hesitation.

Hi JackFlash, I am considering getting a 85mm TB for my car. Can you tell me what all you had to do. Did you have to take it to the dealer? What brand did you get? Have you discovered any down side from making the change?

Thanks

I used the modern muscle 85mm TB. It works great. Billet Tech will port the one you have on the car, if you send it to them, but then the car will be down a while. It is a well worth mod in my book. Made a big difference, my car really liked it, but I don’t think you gain much hp, just drivability. It eliminated all the hesitation, dead spots, and made accelerating very smooth. They are really easy to put on. It takes at the most ½ hour.
You can either take it to the dealer and have it calibrated (not really necessary), or turn the key on (don’t start the car), depress the throttle slowly and let it back up slowly, then turn key off. This is said to calibrate the plates as well. In the “easter eggâ€

[broadfca]

I installed an 85mm throttle body on my R/T and it eliminated this problem altogether. The throttle response is smooth at all rpm's now with no hesitation.

Hi JackFlash, I am considering getting a 85mm TB for my car. Can you tell me what all you had to do. Did you have to take it to the dealer? What brand did you get? Have you discovered any down side from making the change?

Thanks

I used the modern muscle 85mm TB. It works great. Billet Tech will port the one you have on the car, if you send it to them, but then the car will be down a while. It is a well worth mod in my book. Made a big difference, my car really liked it, but I don’t think you gain much hp, just drivability. It eliminated all the hesitation, dead spots, and made accelerating very smooth. They are really easy to put on. It takes at the most ½ hour.
You can either take it to the dealer and have it calibrated (not really necessary), or turn the key on (don’t start the car), depress the throttle slowly and let it back up slowly, then turn key off. This is said to calibrate the plates as well. In the “easter eggâ€

[broadfca]

I installed an 85mm throttle body on my R/T and it eliminated this problem altogether. The throttle response is smooth at all rpm's now with no hesitation.

Hi JackFlash, I am considering getting a 85mm TB for my car. Can you tell me what all you had to do. Did you have to take it to the dealer? What brand did you get? Have you discovered any down side from making the change?

Thanks

We just installed an Arrington 85 mm TB in my buddy's 09 SuperBee last night. Can't imagine it's much different than just pulling off the air intake tube, unbolting the old TB, and bolting in the new TB and re-installing the intake tube.

What are the results of installing the Arrington TB? Did it eliminate the bogging and dead spots on acceleration?

[Cruisin1966]

What are the results of installing the Arrington TB? Did it eliminate the bogging and dead spots on acceleration?

So far so good. His car never bogged down as much as mine, but he seems quite pleased with the performance of the car with the TB. He's still data logging a little to see if there are any differences between now and before.

[broadfca]

What are the results of installing the Arrington TB? Did it eliminate the bogging and dead spots on acceleration?

So far so good. His car never bogged down as much as mine, but he seems quite pleased with the performance of the car with the TB. He's still data logging a little to see if there are any differences between now and before.

Any update on the new TB? I'm very curious because if the new TB has helped with the bogging and hesitation, then I'm going to get one right away.

Thanks

[1RTSTEVE]

BROADFCA, Have you tried to calibrate your throttle?

Turn key on, press slowly and hold down pedal for a few secs, slowly release and repeat then try it, it has helped me.