[GueSS Who ?]

This is for a local 10.5 class.
02 camaro on 275s
The new X275 88 turbo
10.5:1 [email protected]
Solid roller, probably spinning to 8k max.

Not sure what A/R to get this turbo to make it right? All suggestions are welcome with a reason why. I really like learning about this stuff.

 

[BOOSTED-SS-ELKY]

2000hp....

 

[GueSS Who ?]

1300 to 1500rwhp.....Not sure,

 

[BOOSTED-SS-ELKY]

I'm sorry, I thought you were asking about what size intercooler to run?

 

[GueSS Who ?]

I'm sorry, I thought you were asking about what size intercooler to run?

Actually it has a Shearer 3K a/w

 

[nmracing]

Actually it has a Shearer 3K a/w

Which "new" x275 turbo? Gt4788 Gt5588 large frame etc...

 

[GueSS Who ?]

It is the large frame. Not sure all the details about it but I don't know that it has been out long.

 

[whatbumper]

1.32 or larger with that cubic inch
My motor is smaller with a 1.15ar and I'm changing to the 1.32
My $.02

 

[GueSS Who ?]

Anyone else have any info. Looks like the 1.32 might just be the one.

 

[LilJohn]

Well it depends on which hotside it is. If it's a gt55 you'll go tighter on the a/r than you would if it's a GT47 because the bigger wheel will allow you to. If you are going to a bigger housing because of drive pressure issues I don't think you will solve your problem. The wheel is the restriction, the housing just dictates where in the rpm band spool happens. I think that is the key to these limited size combos. Big wheels, tight housings, so the spool happens early and you can use your power management device ( ams1k ) to put the power down like you need it.

 

[GueSS Who ?]

Well it depends on which hotside it is. If it's a gt55 you'll go tighter on the a/r than you would if it's a GT47 because the bigger wheel will allow you to. If you are going to a bigger housing because of drive pressure issues I don't think you will solve your problem. The wheel is the restriction, the housing just dictates where in the rpm band spool happens. I think that is the key to these limited size combos. Big wheels, tight housings, so the spool happens early and you can use your power management device ( ams1k ) to put the power down like you need it.

It is the gt55. Are my cubic inches to much. Not sure what the drive pressure is going to be but I am worried about getting the turbo going quickly for the 60ft. This is only 1/8 mile racing.

 

[koolrayz]

I am getting ready to order the same turbo. It is the precision X275 with the thumper large frame turbine G trim.
My engine is a 427.

 

[Shearer]

Yea it's not a GT55 hotside.

 

[whatbumper]

Well it depends on which hotside it is. If it's a gt55 you'll go tighter on the a/r than you would if it's a GT47 because the bigger wheel will allow you to. If you are going to a bigger housing because of drive pressure issues I don't think you will solve your problem. The wheel is the restriction, the housing just dictates where in the rpm band spool happens. I think that is the key to these limited size combos. Big wheels, tight housings, so the spool happens early and you can use your power management device ( ams1k ) to put the power down like you need it.

Yeah I didn't go into all of that stuff but your right. Pulled a Precision 106 G trim with a 1.0ar off and switched to a BW 88mm with a 1.15ar. The exhaust wheel is badass on the BW. I had to add a lot of time to the boost controller to calm it down enough to get down the track. Huge difference on the front half. I'm hoping it won't be so hard to control with a larger exhaust housing. The BW is a little bigger physically also and I almost didn't have enough room. LOL

 

[LilJohn]

A wheel that big is gonna need a tight a/r so you can get it to spool and not be lazy the first 330. That's gonna be you key to getting down the track. Make it spool early then use your boost controller to back it off however you need to. If the a/r is too big, you won't be mechanically able to make to boost. And if you can't do that, the Ams or whatever contoller you're running, has nothing to control.

 

[Shearer]

Nice hypothesis!

 

[koolrayz]

I am thinking I will go with the 1.0 AR
It may cause backpressure issues on the big end but the heads up stuff I want to run is the X275 1/8th mile. I run a half dozen 8.90 index races but my car is clowning at 8.90 and am not worried about backpressure or maximizing the 1/4 mile for internet time slip racing.
What do you think?
Sorry for the thread jack. If I was the OP with 50 less cubes I would be looking hard at the smaller AR

 

[LilJohn]

Shearer, nice hypothesis maybe, i would rather know that it's a correct theory you know. I sit behind the wheel thinking about this crap all day going over things I read, comparing combos to the way it runs at the track, but people like you who do this stuff for a living have way more information to base things off of. If I am on the right track, thank you for the compliment.

Coolrayz, I think a 1.00 would be a good place to start for you. I have that same
Turbine wheel going on 496 inches and I'm thinking about using a 1.32 IF I ever get the chance to race the car competitively. That reads win the lottery. That wheel has a 113 or 114 mm exducer, I can't see you having backpressure issues on 427 inches. If the 1.0 works, and you do, I'd look at everything else in the system first before I changed it. If you wanted to order your turbo with a 1.32, I have a 1.00 that I would trade, sell ya. How much room do you have for exhaust? It's been suggested to me to try and fit a 6 inch downpipe on my setup, might work for you too.

 

[GueSS Who ?]

Shearer, nice hypothesis maybe, i would rather know that it's a correct theory you know. I sit behind the wheel thinking about this crap all day going over things I read, comparing combos to the way it runs at the track, but people like you who do this stuff for a living have way more information to base things off of. If I am on the right track, thank you for the compliment.

Coolrayz, I think a 1.00 would be a good place to start for you. I have that same
Turbine wheel going on 496 inches and I'm thinking about using a 1.32 IF I ever get the chance to race the car competitively. That reads win the lottery. That wheel has a 113 or 114 mm exducer, I can't see you having backpressure issues on 427 inches. If the 1.0 works, and you do, I'd look at everything else in the system first before I changed it. If you wanted to order your turbo with a 1.32, I have a 1.00 that I would trade, sell ya. How much room do you have for exhaust? It's been suggested to me to try and fit a 6 inch downpipe on my setup, might work for you too.

Now that you got Ray's combo figured out, What do your think about mine. 376CI 10.5:1 ls motor. only 1/8 mile racing. Just trying to get the closest one the first time.

 

[Shearer]

1.0. I'll call ya tomorrow.