Hey guys I just bought my jet hot LT's today and from what I have read here I should just get a custom y pipe made, but I have two questions:

1: When I go to the shop what diameter should the pipe be and what kind of steel if it matters?

2. Also without a cat will I not have enough backpressure and therefore lose power?

Thanks for the info!

 

need backpreasure for more power? who fed you that BS?

you dont want backpressure,
get 3" all the way to the back with high flow anything that your putting in the pipe.

 

I thought that some level of backpressure was necessary???

 

nessesary for what?

you want backpressure then dont install your headers.... you manifolds have lots of backpressure.... but as you know do not produce the most power....

shorties have less pressure, and produce more then the manifolds

LT's make more then shorites, and have less pressure then the shorties....


take what you want from that.
if you want backpressure run a 2.5" pipe instead of a 3"

also if you plan on keeping the car, and or live where the car gets wet then get stainless pipe, you'll save the meney later from not having to redue it when it rusts out.

 

twin 2.5 pipes arent going to hurt. Gives you better clearence too.

 

I was under the impression that backpreassure helped with torque somewhat.

 

from where?
if you make a 2.5 or a 3" Y the header flanges are still the lowest point.


it wont give you more TQ but it can move it around a bit.
when I dynoed efor and after my cat back I didnt get much TQ 7 ft, and 11 hp, but it sure did make my tq curve longer and flatter.

 

The collectors will still be lowest point, but they are more centered over the wheels. The areas farther from the wheels will be most likely to hit because that area of the car doesnt "follow" terrain. (not sure if thats worded clearly)

in example.... Speed bump. Go over and tires rise over it and then fall. That likely is enough to clearance the collector flang. However the Y has nothing to lift the body over the bump b/c the front wheels have cleared and the rears havent hit it yet.

Anyways, i made the numbers in sig with twin 2.5 Y.

Food for thought....

Twin 2.5 inch pipes has total cross section of ~9.8 ci

Single 3 inch cat back only has ~7.0 ci crossection