T4 70mm Turbo

Garrett Internals:
Compressor:
70mm / 62 trim wheel
4" Inlet / 2.5" Outlet

Turbine:
.81 A/R

I am looking into building my own turbo setup. I have a 98 Cobra with the 4.6 liter 32v heads. I am wondering if this turbo would be a good choice. I want it spool correctly. I also plan on running low boost 6-8 psi until I am ready to rebuild with forged pistons and rods.

or would this be better match for me: garrett GT35R?

Compressor: T04S housing (4" inlet, 2.5" outlet)
56 trim .70 A/R , flows 65 LB/MIN

Turbine: T3 inlet, 3" outlet (V-Band)
84 trim .82 A/R
I have a friend who built his own on a 99 gt 4.6 2v and is making around 445hp to the wheels.
I have also been looking at this setup for a waste gate and BOV, boost control combo.

JDM HKS Turbo SSQV Blow off Valve Style.(Dual Stage pull-Type Relief Valve).
HKS Style 38MM Wastegate.
Adjustable JDM Turbo Boost Controller.(1-30PSI)
I am expecting plenty of flack but hey thought I would ask.

thanks for any feed back..

 

those turbos are two small for my taste

ar for the turbine should be at least 1 and the compressor >1

 

If the a/r is high won't it spool to fast?

 

bigger ar slower spool

the turbo u posted will spool at idle

 

ok I got it now. so you are thinking around a 1.00 a/r ? Do you know of a place that sells them sort cheap but new. All I can find on ebay is a T04B A/R .60 A/R 1.00 S-Trim I think this will limit hp guy says it's good to 350hp. how can this be?

all specs: Offered is a Brand New T04B Turbocharger , again Brand New in Box its got A/R .60 on Compressor Side and A/R 1.00 on Hot Side , S-Trim T04B good for up to 350 HP . This is an High Quality Turbo Made with High Quality Parts. CHRA is Oil Cooled. Turbo's are perfectly balanced , Integral Dynamic Balancing of each Turbo for Best Performance , Off-Balance Amount is less then 20mg. High Temperature Resistance, Key Parts made of top quality NI-Cr K18C Material, no deformation on working temperature up to 1100 degrees Celcius . Outstanding Wearability , Quality Cu-Sn Floating Bearing.

also this gives me data on inlet/outlet for compressor and turbine exhaust out size. what do you think good size for my setup would be. I was thinking 3-4" inlet on comp 2.5" out and no less than 3" outlet on turbine..

 

That turbo is good for a 2.5-3.5L motor. Honestly, if I were you, I'd be looking for a nice LARGE turbo. Maybe a T61 or T66. However, if you wanna use something small like what you're looking at, I'd recommend getting two.

You can build the 4.6L to be a 350hp monster without boost. But if you want boost, and only 450 or so hp, then go with two large T3's or smaller T4's like you have listed in your first post.


Wink

 

My car has dynoed 277hp 268tq at the wheels with current setup. 350 would not be that great for all the work. Hoping for at least 400 at the wheel with low boost. thank you for all the input as soon as I have gathered some parts I will be posting pics of my progress along the way. Feedback is good. I also have four O2 sensors on my car two before and two after the cats . do i run the first pair on the way to the turbo? As before I listed some boost control products. will they work or are they crap?

Sofar:
Granetelli tube k memeber and A arms
FMS A/C eliminator ( Both to make room and lighten it up)

BBK 255lph fuel pump
FMS 42lb injectors
Recaled mass air for the 42's

thanks again..

 

go here, http://www.gnttype.org/techarea/turbo/turbocalcs.xls

download the excell ------sheet

fill out as much as you can (only the blue items are editable)

when you fill out as much as you can, look at line 53 and line 54

use those 2 #'s and plot them on a compressor map.

that will give you a real good idea on what a good turbo would be for you. however, you will need to search for the compressor maps, but thats easy... so here you go... http://www.rbracing-rsr.com/turbotech.html


let me know if you need any help with that.

 

also, FYI....

with a quick rough guess on the ------sheet..

at 8psi i came up with....

48.7 lb/min
1.78 p/r

this would plot you on the far right hand side of the center island on a t70 compressor map...

and you would stay on the right hand side of that island up to about 18-20 psi, and even then your only out of the center island by a very tiny bit.


i think the t70 would be a good choice for you.

 

thank you for your help. T70 is alot bigger than what i was looking at. but i came up with the same figure based on the charts and calculators you provided. found a guy willing to part with his new one for 420 bucks. is that high?

this is his add


This is a True Super T-70 Turbocharger. 4 Inch Inlet, 3 Inch V-Band Exhaust, Wet Floating Ball Bearings, Balanced and Tagged.
It will come free with Beautiful 7076 T6 CNC Machined Aluminum Oil Inlet and REturn Flanges, Gasketted and Installed. Together a $40 Value. The Inlet Flange is a male -3 AN Sized fitting, while the Return Flange is a -10 AN Female fitting.

Both Compression and Exhaust Housings are Clockable.

This is one Big turbo. It will best work on larger displacement engines, probably 3.0 Liters and abover, since anything smaller would probably not spool up as quickly. I was going to use this turbo on my Fully Built Ford 5.0 (302), but am selling it all off.

let me know..