AR's LSnotch

Sup guys am about to start doing my hot parts doing a LS swap on my 89 mustang notch . Running a 2007 5.3 with truck manifolds flipd .. Still have my crossover hot parts from my old set up 357w but is a 3 inch cross over the turbo I have an planning on running is a T6 s400 Borg Warner 75 mm 1.32 AR . An my question is will that kill me if I run this turbo wit a 3 inch crossover on my 5.3 . Will I have alot of boost lag

Am planing on running 14 to 18 psi of boost
Wit supporting mods


Thanks

88mmrocket

3" is too big. Yes it will work and it will have some lag but if this is going to be a track only car then it may be ok. The issue will Be when out of boost and trying to get back in to it.....ie blowing the tires off and trying to recover.

Run 2.5" or 2.25" pipe if you can. You are going to need the velocity to spin the turbine wheel.

It will fly though!

AR's LSnotch

One of my buddy's told me is to big but wanted to kno if it will really kill me ... I got a straight pipe that I'm gonna use then is 2 7/16 for crossover an another question
Can I use that same t6 merge 3 inch to the turbo or should I go all the way 2 7/16 "

jridenour31

Definitely too big, 2.5" max.

conan

iTrader: (5)

Not a turbo guy but I read through this a while back, might help you out.

https://ls1tech.com/forums/forced-in...over-pipe.html

shawnc16

2 1/4. Fits perfectly with a divided T6 flange as well for the merge.

TurboJoe@Straightline

Lol...this is more of that hocus pocus...2.5 is great cuz everyone has that size and it works great. But after a couple big boost cars we have had on the dyno and seeing there spool times with huge turbos and smaller motors with there "horrible" sized hot sides I find that it just does not matter that much! Guy yesterday with 2 in primary's and a 3 in crossover made north of 1200 and boost was there around the 36-37 mark. Just do what u can get and make work.

Look up willamz on here and his tiny 5.7 with 3in crossover. He has a 3in crossover and it did not affect his stupid numbers!

BMF_Racing

iTrader: (6)

I've always used 2.5", but may use 2.25 or 2" in the future (pending on the hp goals). There was a guy recently post up 850whp with 2" crossover with no back pressure issues. Really no benifit at all for 3" in my eyes (cost more than 2.5 and 2.25" and is slower to spool due to the greater area). Just my $0.02, GL.

bad6as

iTrader: (17)

Ide say 2.25 On that combo

jridenour31

It's definitely not hocus pocus. Phil has posted tons of logs showing the difference in spool with different crossovers and primaries. Saying it doesn't make a difference is just flat out wrong.

BMF_Racing

iTrader: (6)

X2 true

Cam72aro

iTrader: (28)

I did 2.5, but if I had it to do again I would go 2" or 2.25" max. Blackws666 I think is the screen name did 3" and had a bunch of lag, went to smaller pipes and noticed a big difference.

Phil99vette

iTrader: (11)

I have worked with guys that have done various different sizes. A properly sized pipe based on velocity will work better and make more power under the curve. Fact.

2" crossover, merged into a 2.5" that goes into the turbo, easily good to 1000rwhp.

I am still using a 2.5" on a 460" methanol 118mm combo.

Phil99vette

iTrader: (11)

Anyone can make power at the top end of the motors legs. Whats the boost curve look like, how does it come up on the converter or does that even matter?

Phil99vette

iTrader: (11)

And FWIW, turbine/Turbine housing dictates backpressure.

bad6as

iTrader: (17)

I would redo mine again if i had the chance or the need, its 2.5'' Now. But this was befoe phill posted that info.

Phil99vette

iTrader: (11)

I have not had one person say.... I wish I had stayed with my old 2.5 or 3" piping. Just sayin. Couple of people went to larger turbines.

AR's LSnotch

I did my own merge 2 1/4 had to weld both sides on t6 flange an hit wit hammer to open the pipes wider to be able to weld inside an out to big of a gap

AR's LSnotch

So should I do 2" for crossover an merge it to my 2 1/4 or go 2.5 all the way

Phil99vette

iTrader: (11)

Roll with what you have and post the results.