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Physically smallest turbo to support 425 rwhp?


rustrocket

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Hey everybody. I'm in the midst of doing a ka turbo swap into my triumph spitfire. My original plan included a holset hx35 turbo, but after mounting it on the engine and sitting the engine in the car, i've realied there is no way i can make it work because the physical size of the turbo severely limits my manifold and placement options.

 

So i come to you guys looking for the smallest turbo possible that'll support around 425 horsepower to the wheels. A couple people have suggested to me the Garrett 2871? model, but the $1100 pricetag makes my wallet cringe. Any suggestions would be great. It doesnt matter if it's a t3 or t4 flange, as the final manifold hasn't been made yet.

 

Thanks.

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Here it is...the turbo is so big that A: It hits the wheel arch (one piece front end similar to viper) B: The exhaust housing is right up against the firewall. After talking to a couple manifold guys, they told me getting a smaller turbo was the only way i could work with my setup.

 

IMG_1589.jpg

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That's pretty big... Any reason why youve chosen 425 whp? Do you have a specific 1/4 mile goal in mind?

 

If you want big horsepower in a small package, then you need high efficiency. That means Garrett GT, and that means >$1000

 

I'd stay away from the T3/T04 unless you like lag, and it's not particularly small in size either. The 2871 is a very good, efficient turbo. I'd suggest the GT28RS Disco Potato, but thats a little shy of your horsepower goals, and is still $900+. You could also try finding one used.

 

 

- Greg -

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I've chosen 425 horsepower because i'm obsessed with big numbers and excessively powered cars. 425 would give me roughly 1 horsepower per 5 pounds laden weight...

 

I dont ever plan to drag race this thing...it'll see some track time though, at thunderhill or sears point.

 

Do you have a 2871 or disco potato on hand that you could measure for me?

 

The appeal of the 2871 is the dual ball bearing...How much bigger is the gt30r?

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Do you have a 2871 or disco potato on hand that you could measure for me?

 

I have a DPT I can measure for you. The compressor housing is the big part' date=' obviously, but let me know what you want measured. Or you could go here: http://www.atpturbo.com/root/turbopiping/dimensions/gt28rsdim.htm

 

Looks like they claim the 2871 will only flow enough to support 400 whp. If youre set on 425, you may have to go with a 3071 or bigger. Definitely go with a Garrett GT turbo though. They are head and shoulders above the competition in technology and efficiency.

 

Here's a good list: http://www.atpturbo.com/root/turboinfo/gtlineup/gtlineup.htm

 

 

 

- Greg -

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ive got a gt2871r. i got it with a T3 turbine housing for use with an external gate, and a 4" compressor inlet.

depending on how you clock it, its basically a 9x9x9 cube...[its a little smaller than that actually]

 

ive heard they're good for around 400hp... idk the exact amount... hopefully mine can make a bit more because it'll be able to flow more, the basic gt2871 is like a t28.

 

pics

turbocame003.jpg

 

turbocame002.jpg

 

turbocame001.jpg

 

price was 1145 shipped iirc from himni racing.com

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gotta pay to play when you want to keep weight/size down and efficiency up.

why not splurge on a good turbo?

 

COME ON!!! you know you wanna :D

 

A GT series turbo isn't any more effecient on the compresor side. They aren't any smaller or lighter for similar HP rated turbos. The exaust wheel efficiency may lead to a slightly faster spool but what's 100-150 rpms compared to the extra $500+.

 

I would use a log manifold instead of that turbo header and move it in and forward. Do you have a top pic?

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Thanks for the suggestions everybody.

 

I dont have a top pic, but after talking to a turbo vendor, he offered the suggestion of changing the exhaust housing. My current housing is designed for the dodge 2500...Bullseye power makes a stainless housing that is significantly narrower. Between this and moving the entire unit forward on a long manifold by about 2 inches, i think i can manage.

 

Should i be concerned about the compressor housing being close to the spark plug wires/distributor?

 

And veritech, i would say you've been more spoiled than i have!!

 

For reference, here's a pic of the dodge holset housing vs. the bullseye power housing:

 

ShowLetter1.jpg

 

ShowLetter2.jpg

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