Most people say that installing pre-cat deletes will reduce low end torque, but it also seems like most people that have pre-cat deletes also have the rest of their exhaust done ( j-pipe, third cat delete, and cat-back). I can see how this would reduce back pressure and therefor low end torque.

My question: If i install pre-cat deletes and j-pipe (possibly with test pipe), but leave my cat-back completely stock, will i still experience this low end torque reduction, or will the stock cat-back provide enough back pressure?

Seems like pre-cat deletes are the single mod that provides the most gains not including SC or turbo, so i wanted to get them on, but if i will lose my torque id rather just go with the j-pipe and XLR8 catback.

 

no you won't experience much low end loss but you sure will be giving up a ton of topend...

try the precats alone first... I've always theorized precat deletes alone would yield some nice low end tq

 

sorry, why would i be losing high end power with precat deletes and j-pipe? i thought i would be GAINING power across the curve...

 

you said precats jpipe 3rd cat delete and your STOCK EXHAUST... that's what I ment as the root of the top end choke

 

hey al, would this setup be very raspy??

 

Pretty much what I have (oem catback). You heard many of my videos. Minimal rasp. My setup is =

Precat Deletes --> XLR8 Jpipe --> RV6 Race pipe --> oem resonator --> OEM catback (but with midmuffler deleted)

 

Your car sounds awesome!! I want the same setup but I have my resonator deleted as well. That might bring some more rasp

 

Gotta have the resonator if you have the PCD.

PCD + No Resonator = drone city

 

Do u have motor mounts with those Innacurate?

 

Yes. I have the IM Black 75A. The complete set (front, rear, and side) is Black 75A.

 

Ouch isnt that harsh?

 

inaccurate, seems like your exhaust setup is exactly what i want. Why have you chosen to keep your cat-back stock, and how do you like your setup sound wise and performance wise?

 

Don't forget rasp in the cold weather.

 

Yes you'll feel the high end bump but you really didn't feel a loss of low end torque? I know I did.

Not knocking the product... just sayin.

 

jmkiang you have precat deletes with j-pipe, but stock cat-back? cuz thats what stillhere was talking about i believe

 

i love the im 75A. they don't seem that bad and its kinda like getting a back massage when the car is idling. lol

 

FYI, "backpressure" does not create low end torque. I wish that idea would die. When drivers experience reduced low end power after adding an exhaust component, usually the problem is with reduced exhaust velocity in the low rpms. Adding large exhaust pipes might improve the overall exhaust flow numbers, but in the low rpms, the exhaust gases become turbulent in the pipes because the exhaust pulse is reduced and the gases loose their heat therefore slowing down in the pipe and ultimately causing that soft, weak feeling low to midrange power. The key to a good exhaust system is to keep exhaust velocity up over the powerband. Bigger is not better. There's a fine line between too small a pipe and one that's too large, when it comes to NA motors. Reducing low/midrange power can have a HUGE affect on your 1/4 mile time. The car might actually more power from 5000rpms+ on the dyno, but if it's 0' to 100' time is weaker, the car will be slower in the 1/4 mile. Additionally, there's also good reason why OEM exhaust use heavy thick gauge stainless steel, to keep the exhaust gases hot and also for a bit of noise suppression.

 

Nope I'm no longer running PCDs.... but when I did:

AEM CAI -> PCD -> RV6 j pipe -> RV6 HCF -> Comptech catback.

 

Crazy harsh when the mounts were new. After being broken-in, they are not bad at all. From reading comments from members that have the Red 60A, it sounds like there is little difference in the harshness between the 60A and 75A after both are broken-in.

See link below for my full review.

My comments on the Innovative Mounts (click here)

 

went to have my mid muffler deleted and the guy cut off only the resonator and left the mid muffler... he said no difference whatsoever. what will be the difference because everyone on here says mid muffler delete with stock resonator is the thing to do for stage 1, and my exaust guy says it doesn't matter...that they do the same thing.

 

same for me

 

Dave_B, first of all thanks for your input! As you said,
"The key to a good exhaust system is to keep exhaust velocity up over the powerband."

This is exactly what i am attempting to accomplish. Im trying to figure out what exhaust combination of pre-cat deletes, J-pipe, third cat, and cat-back would give me optimal power across the curve.
I figured if i did all of those mods i would lose too much low end power, but maybe if i did the pre-cats, j-pipe, test pipe, and kept a stock cat-back i would keep my "exhaust velocity" up across the curve. really what i am trying to figure out is which combination would be the best for the entire curve. and improve 1/4 mile the most

 

i have the same set up as inaccurate i dont think i have lost any mid/lowend power, the rasp arround 3k imo makes my set up sound cheap, then again, it is, a bigger resonater would be a great addition
i had the same power loss that alot of people discuss on here due to knocking, i have been using an octane booster every fill up and this problem seems to have disapeared, at first i thought it was just because the weather had cooled off, but i was rolling arround in 80 degree temps the other day, stop and go traffic and i had no power loss.

 

What is "knocking"

 

To the OP,

IMO I have the best exhaust setup with good power throughout the band. PCD, XLR8 J-pipe, Procat HFC, and custom catback exhaust (similar to aftermarket catback).

Prior to this I had the stock 3rd cat in place of the HFC; I had huge low end power and no good traction (especially in the rain). But my topend was lagging a tad. Since adding the HFC, my lowend has reduce alittle and my top end is great! Now my car accelerates smoother and quicker due better exhaust flow. Also way better traction off the line! My .

 

I have pre-cat deletes, j-pipe, and stock exhaust. When installed the deletes, I felt little to no gains but maybe that's just me. I''m pretty sure when I open my exhaust up, I'll feel some great gains.

 

hello all,

I just purchased my 07 tl s the other day and already getting the mod bug. I am interested in doing the pcd,j pipe,hfc,stock exhaust

Does anybody have a video of this set up?? I do not want raspy or drone, if there is i will most likely stick with J pipe and 3rd cat delete

 

what was the final consensus on this all these years ago. Is there a loss of low end torque/power with the pcd's