Hello all.

Currently, my 2012 g37x has Invidia catback exhaust, FI HFC, Motordyne Intake, and Takeda CAI with Uprev tune. Over the weekend, I installed EPS tuning throttle bodies. After the install, the car became noticeably slower. I plan to retune, but I wanted to see if anyone can offer input from the community. Anyone experience something similar before retune? I didn't expect it to be this much slower, but maybe that's because these TB's are not accounted for in the original tune? The pick up on the car sucks now!

Talking to a buddy, he told me it's pointless to add bigger TB's then use an adapter to choke it back down to the original size of the intake. Hoping a tune can fix this, otherwise I'm going back to stock TB's unfortunately.

Will talk to the tuner during the week and see what he says.

 

Bigger TB's like the EPS will make the car drive like *** if it's untuned, especially on the tip-in acceleration / pick-up. I'd say this mod is more suited for forced induction setups or fully built NA setups with a full custom tune.

For your car, the EPS TB's will work better if you have upgraded exhaust cams, ported intake manifold, test pipes, and a custom tune. Otherwise, gains will be minimal, and you'll better off with stock TB's with stock driveability.

I would take the EPS throttlebodies off and sell them off. The gains from these throttlebodies + tune is not too ideal.

 

Yes it will drive bad until you get retuned because the amount of air being sucked through is now different.

 

I will say that the light and mid acceleration already feels more open and picks up better already after bolting on. It's only the WOT that seems to not fully deliver. It already has a tune on it, but for the stock TB's and the rest of the supporting mods I have. Hopefully the retune next weekend will work that wide open throttle out. Otherwise, I'm better off back to stock TB's and the tune that accompanied them.

 

I went back to the stock TB's. Takeda intake pipes restricting the MAF too much and unless I swap those out to match the TB sizes and upper intake, I won't see a gain. Felt better with the stock.