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http://www.billetturbochargers.com/Billet_A-GTA.ews


Billet A-GTA

• Standard compressor options
Billet-A, Inducer 47.7mm, Major 60mm. 63 trim.
Billet-A, Inducer 46.4mm, Major 60mm. 60 trim.

• Standard compressor cover options
Billet-B .60 A/R, 3” inlet, 2” outlet.

• Compressor cover optional upgrades
Bullet port shrouded Billet-B .60 A/R, 3” inlet, 2” outlet.
Billet-B .70 A/R, 3” inlet, 2” outlet.
Bullet port shrouded Billet-B .70 A/R, 3” inlet, 2” outlet.
Nissan S15 Silvia .60 A/R, 2 bolt inlet , 3 bolt outlet.

• Standard turbine
Billet-GTA. Major 53.8mm, Exducer 47mm. (76 Trim)
Billet-GTA. Major 53.8mm, Exducer 46mm. (73 Trim)

• Standard exhaust housing options
GT28 Open .64 A/R, .86 A/R.
Includes Bracket, Actuator can, rod and flap assembled.

• 250hp to 380hp

Is your engine built, or stock? Do you want big lag and big power, or small lag and less power?

i paid 1400 for this turbo, i didnt think that was too bad considering i got quoted 1100 for a rebuild on the hitachi HT18 that the car came with. I'll admit i didnt shop around much tho. i had a mate buying a turbo of billett and i really didnt know much about turbos at that stage.

I had another friend stirring me up saying that it is meant for a 2.0l engine (silvia) and so he predicts that it will be hitting boost late and hard... i really hope not.

I am getting a haltech installed and i have 2.5" exhaust right through... fingers crossed.

Yeh that was the price new and yes, mine is the one at the top. I'm glad to hear that you think it will be fine.. i have been a bit worried that i would be out of control at the end of each gear when the boost hits..

Say that it does turn out that i am getting late hard boost, what are the fixes?? i already have bigger wheels and 2.5 exhaust.

Here is a picture of the turbo bolted on.

ShadyDeals wrote:Yeh that was the price new and yes, mine is the one at the top. I'm glad to hear that you think it will be fine.. i have been a bit worried that i would be out of control at the end of each gear when the boost hits..

Say that it does turn out that i am getting late hard boost, what are the fixes?? i already have bigger wheels and 2.5 exhaust.

engine.JPG

Here is a picture of the turbo bolted on.

The only way to spool a turbo faster is to punt more flow through it, and to reduce back pressure.

Your 2.5" should be fine IMO so that leaves you with one option - increase flow into the snail.

This will probably mean $$$ in the form of more capacity (1.8L conversion or a bore/stroke), and/or head porting, etc. Intake mods may yield minor improvements.

All this assumes that your tune is on the money and all other things are equal...

E85.

Seriously, its a 15% power (Yes that means exhaust flow too) increase, that will get you on boost 15% earlier and make 15% more power EVERYWHERE (yes I oversimplified this but its close enough). Not to mention with it you can safely run more boost, assuming your bottom end can handle it.

Dann

Tuning can assist turbo spool.
The overly simplistic answer is reduce timing and add fuel just before where it's making boost.
The hotter exhaust temp will aid spooling, although it's not always god to the turbo...

That turbo looks like a great size, the .64 housing would be nice on a stock engine with 2.5 exhaust, the .84 rear might be nicer on a stronger engine with larger exhaust.

I'm running a Garrett GT2860RS Turbine A/R 0.64 on my 1.6 and to be honest it's a little large, even with porting, 25/65 cams, 8.2:1 pistons, tubular manifold and 3" open exhaust. Time again I'd choose a GT25 to get on boost a little earlier. Might not make 300RWHP but I can't use it all in AutoKhanas and short track sprints anyway.

8.2 compression is way too low, thats your spool issue. Your turbo really isnt that big. Also your cams dont improve flow below the boost threshold, they reduce it, also hurting your spool.

Dann

Yep, what Dann said.

That's a fairly low comp ratio, but your turbo isn't that big even for a low comp 1.6, guess it comes down to what you want to do, it sounds like you've built it for big power? For autokhana, a stock MX5 is a good car, stock with a bolt on AVO kit will make power pretty much right off the bat, no engine build required.