New Bolt Ons, Torque Loss?

[GTBOB]

That’s a question to ask your tuner. Hopefully he didn’t just work on the maf curve of the intake tube and lower the required IMRC voltage threshold for the 18 intake and call it a day.

Sponsored

 

[Bluemustang]

Have your tuner add some timing in the low rpms. It will take a lot of the bounce away during the throttle tip in. I had both PBD and Lund do that, and the car accelerates and responds a lot better at the low rpms.

What do you mean by bounce?

 

[aleccesarenriquez]

What do you mean by bounce?

I second this.

Also did more testing on the way home.
First I went Wot in 3rd around 4k rpm. Made tons of noise and didn’t move. Turned off the car, turned it back on, repeated the same pull and there was definitely a difference. Pulled hard and it felt good.

Did another one at like 3.5k, and I felt the car bucking ever so slightly. Almost as if It couldn’t make up its mind if it wanted to pull hard to or not (nothing drastic but it was a small stutter from bad to good to bad to good all in the span of about 1-2 secs).

Tried another pull later on after filling up with e85 (I was using 93 in the previous pulls), and 3rd gear same thing. Tons of noise, no pull. Of course this was after the car had been power cycled at the gas station for fill up (I drove about 10 mins before doing the pull for the ethanol content relearn).

 

[KYLExKILLJOY]

When I had long tubes put on my car it felt slower than it did before, I think the sound is messing with you.

Felt slower... Ran better at the track though

 

[aleccesarenriquez]

Yeah that thought crossed my mind. Wish I would’ve done the manifold after getting used to the long tubes first

 

[aleccesarenriquez]

So when monitoring the imrc voltage this morning, it looks like they’re opening at 3.5k rpm and stay open properly. Well, at least the voltage reading is around 1.45 under 3.5k and reads around 3.35 when reaching 3.5k, which seems normal. The car still responds strangely though. Got some bucking in 4th gear again around 3-4k rpm (again slight changes in torque response, almost feels as if I’m on and off the throttle, but my foot isn’t moving) and 3rd gear feels completely empty at less than 4k.

 

[1badrz28]

What do you mean by bounce?

If you had an automatic, you'd understand. The car lurches under light throttle when accelerating from a stop. When the car was stock it did it, once tuned with more aggressive timing in the lower rpms, it went away.

 

[Bluemustang]

If you had an automatic, you'd understand. The car lurches under light throttle when accelerating from a stop. When the car was stock it did it, once tuned with more aggressive timing in the lower rpms, it went away.

I do have an automatic actually. I understand what you are referring to and my car does exhibit that.

Maybe I should contact Lund ask them to make the timing more aggressive down low?

 

[1badrz28]

I do have an automatic actually. I understand what you are referring to and my car does exhibit that.

Maybe I should contact Lund ask them to make the timing more aggressive down low?

Yes, that will remove the majority of it. It worked with both Lund and PBD tunes I have.

The Lund e85 only tune has it removed, the flex still has a bit. PBD has it fixed on the flex, but says don't get crazy with the 93 octane, run e85 mostly if you plan on "driving" the car. 93 can be used for cruising.

 

[Bluemustang]

Yes, that will remove the majority of it. It worked with both Lund and PBD tunes I have.

The Lund e85 only tune has it removed, the flex still has a bit. PBD has it fixed on the flex, but says don't get crazy with the 93 octane, run e85 mostly if you plan on "driving" the car. 93 can be used for cruising.

Have you experienced situations where: in manual shift mode at low RPMs - (1,500-2,000 RPMs) you get a slight bucking sensation after letting off the gas?
Where the torque converter has not fully engaged the transmission.

I tried explaining this to Lund several times before but have been unsuccessful. It doesn't always happen.

The torque converter on this car makes the transmission feel very loose until it fully engages.

The other problem I have is a slight run on sometimes. Like when you are in gear and let off the gas, the car seems to want to carry on forward momentum instead of losing momentum. Again have tried to explain this to Lund and unsuccessful.

These are my only two qualms about how the car runs.

 

[1badrz28]

The only bucking I got was at the throttle tip in.

 

[w3rkn]

I'm having issues with some new bolt ons.

18 manifold with harness, TSP long tubes, GT350 CAI, 47 lb injectors.
Flex fuel tune

Here is my dyno:
https://imgur.com/a/fLtEaNZ

Torque numbers are low but so were base torque numbers (poorly calibrated dyno?). With everything I gained 80/50.

When I saw the graph obviously I was very excited.

However now that I've been driving it for a while, the car feels strange.

Above 5k rpm it feels pretty good. Pulls pretty hard and obviously revving to 7.5k is great. Any rpm lower than that though, the car feels pretty dead. For example, if I'm trying to pass anyone on the highway, if I drop it to 3rd around 4k rpm and step on it, the car screams but goes absolutely no where (like it literally feels like a normal car acceleration at 4k). It felt much stronger before between 2k-4k rpm. I get that maybe the power band shifted, but according to that graph, there were still gains in that range so should I still be feeling slower?

Does anyone know what would cause this sluggish feeling? Could it be the harness? Tune?

A couple of more details: right when I first test drove the car after the mods, the ABS was engaging whenever I braked. He fixed it but unsure if that hints at some wiring issue. Also, if I ease into the throttle, it honestly feels more responsive than if I go WOT (only at the lower rpms).

Between 3,200 RPMs ~ 4,250 RPMs is a problem with torque. It should be a flat arcing curve.



Also, are you driving with traction control on..?

 

[aleccesarenriquez]

Between 3,200 RPMs ~ 4,250 RPMs is a problem with torque. It should be a flat arcing curve.



Also, are you driving with traction control on..?

I am, but I have tried with it off to see if it affects anything, but no luck.

Sponsored