Hi guys ,

So I have a TT 01 Bullitt and I need some advice ... I kind dont really know what I am talking about when comes to tuning.

Car has been dyno tuned properly and run's great but it miss's between gears , what I mean is that in between quick shift the motor will hesitate a bit ... It's really not a bucking , more has if the car did not realise that the clutch is back engaged and that I am waiting for WOT !!! really frustrating !!! let me know if i need to be more descriptive btw


Setup is fairly simple , Twin turbo Hp kit , C&L MAF "bet you that the problem" , SCT tune on a dyno ...

Let me know what you think ...

 

cant say for sure but ive had nothing but problems with c&l meters, i could in fact be the problem. this was with a na set up non the less. i got a 3" PMAS blow thru before i even started the install of my HP kit. not sure if it would have caused problems but i didnt want to find out.

 

I actually have a Pmas pro tube 3" on the shelf but I think that would mean re-tuning the whole thing right ?

 

if its calibrated for the same size injector i ould think it would be fine. mabye a small tweek? but im no expert

 

I would think so too , but I have been informed differently ...

The tuner who did my car told me the whole thing needed to be re-tuned if I swapped the maf ... I doubt he said that looking for the job and the cash ,since he knows I cannot have the car re-tuned by him since he is so far now...

Maybe I should call Pmas , see about having this MAF re-flashed and throwing it in

 

there was another guy near me that had a HP kit with the C&L and had a lot of hesitation problems. when he switched to the PMAS it ran great. he didnt really have a tune pre-say, he was just tunning with locked timming and fule pressure. i never asked if he had to re tune it.

 

I have a C&L and have tuned the car myself. It ran great until I turned the boost up, pegged the MAF and lifted the head. I've heard a lot of people say bad things about a lot of brands. I had a pro-m before the turbo build, and the car always ran funny, put in the turbo, 42lb injectors, and the C&L 76mm with the 42lb tube, and it cranked up the first time. It actually made me jump cuz I was staring at my laptop knowing it would take forever to crank....But I have heard tons of good things about the PMAS blow through. Calibrated MAF's just lie to your ECU. A tuned ECU should have the proper transfer function, and when you switch MAF's it will be different. So a tune is recommended, maybe necessary. Depending on how close the numbers are and all.

 

Does it still have the returnless fuel system?

It sounds like you are getting a fuel pressure spike that is freaking out the returnless system.

Where are you located now?

 

I am located in Montreal ,

I still have the O.E fuel systems beside a 255lph with B.A.P .... You think its fuel related ? Could I rig up a inline fuel gauge possibly and monitor the surge , if that's what it is ?

About the MAF I am not sure how to proceed to possibly change it out for the PMas Protube , I guess it will have to be re-programmed but for what ? right now it was programmed for Forced induction with 42# injectors ...

 

I wouldn't worry about the MAF

You can actually log fuel pressure from the factory computer. Do you have a Chip or a Tuner? Xcal2 or Xcal3

If you have a flash programmer you can download the livelink software from SCT and actually log fuel pressure to your laptop for free. The fuel parameter that you will want to look at would be - Pressure Drop Across Fuel Rail - or something along those lines.


Also if you have a Boost a Pump it could be hooked up wrong. Is it wired in before or after the FPDM? does it still have the Hobbs Switch that sees boost and turns the Boost a Pump on and off?

 

Thanks for all the help BTW ,


I do have an SCT Xcal 2 and I am a little familiar with Live link ... I already planned on doing a datalog I just was not sure what you needed to look for in it ... Obviously I need to re-create the problem while login right ?

About the FPDM and position of my BAP I will look at this later on today. About the Hobbs switch I doubt it , I think its just hooked up as a voltage booster.

Marc

 

The hobbs switch is the way it was recommended to install it over the years and some people still do it that way. Even though it really effects the driveability of the returnless fuel system cars.

 

Days are getting short and cold so did not take the time to check into the Hobbs switch and the way the B.A.P is wired I was too busy beating the crap out of it

Seriously , I will try and grab a little video of it Idling and even possibly choking in between gears.

I am talking about the idle also cuz its not has stable has it should be in my opinion , the idle is around 800-900 with some very mild but noticeable hunting between 100-200rpms ... While driving I can also notice a supper mild but again noticeable hesitation moving from 2-3000rpm range "smmooooth accelration that is" 10 to 0 in/hg , if it see's boost that goes away instantly... I have a feeling all these things are related. If I unplug the maf while running I guess I could check if its the dirty signal causing that right ? Also will grab the datalog shortly I hope. The weather has just been terrible !

BTW : Plugs are brand new BR7EFS gapped @ .032 , fuel is 94 Octane , tune was done originally by Tim @ mph " he just gave me an open version of the tune that I have not loaded yet" Thanks btw

Thanks for all the help

 

replacing the maf or the injectors will necessitate a tune