Exhaust choke point

[Dhos1]

2.5 cat back system connected to a 3" downpipe...how much will it hurt if any? Thinking about doing a 3" all the way back, but the system I REALLY wanted (RJC) is on backorder.

 

[bison]

The correctly designed cat back 2.5" setup will go well into the 9's. I've seen a lot of crappy 2.5" systems that would choke a low 11 sec car. I have a Terry Houston 2.5" dual on the blue car and trapped 135+ with small turbo and a lot less crap than most people use to run the same. The muffler design and the area where the 4 bolt flange is will determine how good the system is for the most part.


BPE2013@hotmail.com

 

[Nick Micale]

Your exhaust choke point will be at the 90 degree bend on the DP exiting the turbine housing. Any bend is a restriction in flow of a gas or liquid.

As the hot exhaust gas travels through the DP to the 4 bolt flange it cools quickly and therefore occupies less volume the further it goes.

Do the math on the area of two 2-1/2" pipes combined compared to one 3" pipe and consider the cooler exhaust flow at that point?

My race car with custom headers has the turbo turned 90 degrees so the exhaust will exit into a straight DP, and inlet air also has a straight path into the turbo as well.

In the early years on a race car a hole would be cut in the inner fender for the DP to exit straight out!

 

[Dhos1]

Thanks. I may go with the pypes

 

[Turbo6Smackdown]

2.5 cat back system connected to a 3" downpipe...how much will it hurt if any? Thinking about doing a 3" all the way back, but the system I REALLY wanted (RJC) is on backorder.

What sort of parts do you have on your car?

 

[Dhos1]

Not enough to trap 135 that's for sure. Standard bolt-ons plus 60lb chip and injectors. Not sure if the previous owner went through the motor or not. LS1 meter, translator-TE44 turbo-3" DP- Right now previous owner ran a 3 inch single shot and I don't likecthe sound plus it starting to rust

 

[Turbo6Smackdown]

TE44 with 60 pounders isn't bad at all. You could do a lot of damage with that combo. What intercooler do you have? The common choke points for a slightly modded car (turbo-injectors) is the turbo elbow (if you still have one) the neck in the stock intercooler and in my opinion the factory heads (with factory springs) I know there's been stock heads in the tens, but then again there's been stock intake systems in the 10's too. But why in the hell would you want to do that? All you should worry about is getting a nicer 2.5" dual exhaust, pick your mufflers and mount it up.

After that start looking for intercoolers. Do you have a scanmaster?

 

[Dhos1]

stock intercooler has a duty neck on it as well. Yes to the scanmaster. My plan is to upgrade intercoolers over the winter

 

[Dhos1]

Dutt

 

[Turbo6Smackdown]

You can edit your posts in the "tools" button. Just hit edit and make any corrections. As far as your mods, fill out your signature so we can see what we're looking at. Be as complete as possible. Year, make & model, miles on car,along with all your equipment. Tires included. Do you still have the stock cam? If so, is your valve springs and timing chain still stock too?

 

[Dhos1]

Yeah, I was walking into work from the parking lot and couldn't find the edit at the time lol. Not sure about those items, the owner I purchased it from didn't know. I will be taking it down for ALL of those this winter. Probably going to go with pypes system

 

[hawkfan]

Thanks. I may go with the pypes

The Pypes exhaust with the Race Pro mufflers is what I have and it's nice. The Race Pros are a straight through design. Not too loud until you mat it.

 

[Dhos1]

Just purchased the pypes kit w/ Race Pro's.