JDL Turbo Kit - Throttle Response
 

Not sure if this has been covered but I'm finding a few downsides to going turbo.

The 1st one and most obvious is the balance of the car. All the additional weight in the front. Especially since the JDL kit's manifold and downpipe are extremely heavy due to strength. I have come to realize this is the cost of having more power and I can live with that.

The other issue I'm having is throttle response and I believe there is a solution (tuning). Before the turbo kit, the throttle response was phenomenal, rev matching on downshifts was a breeze and precise. After the kit, the initial throttle response isn't there and I have to give way more throttle to get the rpms to rise. I've mentioned this to my tuner (HRI) and his response was that is due to the new MAP sensor.

I'm wondering if this has been the experience for many of you that have gone turbo. Please share your thoughts on how you think I can fix (if possible) this issue.. Thanks in advance.

Hmm. Following!

afaik, the extra piping associated with turbocharging will effect throttle response as well, I.E on my old platform (mazdaspeed3) a TMIC had better throttle response over a fmic. Tuning can likely mitigate a lot of it. Have you done any weight reduction up from and maybe try moving the battery to the rear?

Extra weight, meh. I haven't really noticed a difference in how it drives. Still handles beautifully.

As far as throttle response goes, mine hits hard at 3K+, with stock engine feel below 3K. I had to re-learn how to rev match post-turbo, but as long as I keep it past 3K, the response is fantastic.

GTX2867R
Tuned by IAG

If it lends me any credit, I just finished a 1400 mile roadtrip 30 mins ago. [emoji16]

Sent from my SM-G950U using Tapatalk

Stock engine before and after? The throttle response shouldn't be significantly different.

I'm also turbo, and my throttle response is more or less the same as stock. I'm on a 4bar MAP sensor.

Video for reference.

https://www.youtube.com/watch?v=PCNMSzyTols

This might be of interest

https://www.ft86club.com/forums/showthread.php?t=139784

Yup. Stock motor before and after. I am currently running a 3 bar MAP sensor.

@CSG Mike Which turbo kit do you have is your car? JDL too?

GReddy T518Z.

However, the response is not kit based. If anything, my car's response should be slower; I'm on a journal bearing 18G

What turbo are you running? HRI is a good tuner..

GTX 2867R (Gen2)

What does that mean? Should your setup respond slower because of the 18G but there's some other magic happening? Or is it faster because of the 18G?

He is inferring that CHRA technology and bearing type have significantly more of an impact than the kit does. The technology Garrett implements in the 18G's CHRA is quite old, and the journal bearing response is poor, in comparison to a similarly sized ball bearing assembly.



The issue OP is describing sounds like it is all tune based. There's mapping specific to input percentage vs actuation of the throttle. Example-0 15% throttle can be mapped to open the throttle valve 50%. It does not have to be linear either. The tuner may tune the throttle conservatively (50% input is 25% throttle) and map linearly to provide safety against input spikes causing other issues.

I did not have this problem in the past.
Although I did learn what you can and can't always do in turbo'd car especially at this kind of setup.



GTX2867R
UEL
JDL V1