Which Borg Warner T4 turbo?

[David Reid]

My turbo has now been deemed uneconomical to repair and I am looking at using a Borg Warner turbo (T4 3inch v-band undivided manifold)

 

I am only looking for a Maximum of 550ish bhp (injector limit), but what is more important to me (as its a drift/track car) is a large amount of torque (from running high boost) and good power band.

 

I searched on here and Ryan G is running a S300sx 91/79 and getting 600 bhp from it. In the thread below he thinks its good for 650 bhp, so i am thinking its too big for what i want to do:-

 

http://www.mkivsupra.net/vbb/showthread.php?t=202668&highlight=borg+warner

 

I have been trying to find a list of available Borg Warner turbos and the only place I have found this is at Full Race, below is the link (scrow to the bottom).

 

http://www.full-race.com/catalog/index.php?cPath=214_1167

 

So the options are:-

 

• S200sx 75/70 T4 (A/R 0.83,1.0,1.09,1.15,1.22) FR Rate to 480 whp
  
• S300sx 83/75 T4 (A/R 0.88, 0.91, 1.00) FR rate to 500-680+whp + state GT35 equilavent
  
• S300sx 88/75 T4 (A/R .88, 0.91, 1.00) FR Rate to 450-750whp +state as similar to T04z
  
• S300sx 91/79 T4 (A/R .88, 0.91) FR Rate to 550-830+rwhp
  

 

Now given that Ryan has tried a S300sx 91/79 T4 (A/R 0.88) assuming he is running an undivided exhaust housing, then Full Race are way out on there power estimations. So assuming an actual UK power 100 bhp@ FBHP below the Full race American HP wheel figure.

 

I am thinking the S300sx 83/75 T4 0.91 or 1.0 will get me to my target power with a nice torque curve.

 

But will it choke on a 3 litre?

 

Does anyone else have any experiance of running a S300sx 83/75 on a 2JZ? Or any of the other BW combinations above?

 

Advice please

[Wez]

Are you looking for 550hp at the wheels or flywheel?

[David Reid]

550 Flywheel, but as you can see from the above american wheel figures still seem 100 bhp below UK flywheel figures.

[Wez]

550 Flywheel, but as you can see from the above american wheel figures still seem 100 bhp below UK flywheel figures.

 

Thats normal, you will also find a lot of US figures are based on 2bar boost and race fuel

[David Reid]

Thats normal, you will also find a lot of US figures are based on 2bar boost and race fuel

 

That would explain it

[Chris Wilson]

A lot of US figures are also based on bulls*it, too

[David Reid]

No one?

 

It looks like the choice will be made fore me as they dont have the S300sx 83/75 T4 (A/R 0.88, 0.91, 1.00) in stock.

 

So I will have to go for the next one up 88/75 the choice of A/R they have is 0.88 or 1.00. I cant decide, I think I might go bigger to avoid any possibility of choking.

[Wez]

If I was looking at a BW unit it would be the 88/75 or 91/79

[David Reid]

If you went for the 88/75 which A/R would you go for?

[bondango]

You'll find that most US figures are actually pushing turbo's into new territory, Simply due to the fact that most tuners are switching to E85 which means a lot more timing and leaner AFR's this means that the new tech turbos such as the billets can be pushed into territory they excel in ...2bar+

 

88/75 with a .91 would be my choice on a 3.0, will come in quick and should be pretty linear providing plenty of mid range punch. .81will spool from no where but think it will fall off horribly after 6K

1.00 would be wasted without some cams IMHO

 

Thing is, housings can be had for relatively little money, so you could invest in 2

Edited August 19, 2010 by bondango (see edit history)

[Wez]

If you went for the 88/75 which A/R would you go for?

 

Since I am on a cast manifold I would go for the largest single scroll

[Gaz6002]

I have a twin scroll 88/75 with 1.01AR. My car made 548bhp and 510lb/ft with a restrictive (quiet) exhaust and stock cams at 1.45 bar on Surrey Rolling Road. It's making more power on the road though... I'd like to get it to TDI and see what it's really doing.

[David Reid]

I have a twin scroll 88/75 with 1.01AR. My car made 548bhp and 510lb/ft with a restrictive (quiet) exhaust and stock cams at 1.45 bar on Surrey Rolling Road. It's making more power on the road though... I'd like to get it to TDI and see what it's really doing.

 

Do you have a twin scroll manifold? When does it come on boost? Do you have a dyno print out you could post?

[Gaz6002]

Do you have a twin scroll manifold? Do you have a dyno print out you could post?

 

I do, I'm using the Boostlogic twin scroll manifold.

 

Unfortunately I don't have my dyno sheet to hand, it's 300 miles away. I'll try and dig it out at the weekend.

[bondango]

Agree with Wez, I love cast manifolds with a bigger hotside on a mid range Turbo (500-600) makes a very Torquey setup, but as your tubular undivied i would step down to the .91

[David Reid]

I do, I'm using the Boostlogic twin scroll manifold.

 

Unfortunately I don't have my dyno sheet to hand, it's 300 miles away. I'll try and dig it out at the weekend.

 

When does yours make full boost?

[David Reid]

Agree with Wez, I love cast manifolds with a bigger hotside on a mid range Turbo (500-600) makes a very Torquey setup, but as your tubular undivied i would step down to the .91

 

I am thinking of going 0.88 as the uk importer doesn't have 0.91 only 0.88 or 1.00

[Gaz6002]

When does yours make full boost?

 

Around 3800 in fifth mate.

[David Reid]

Sorry last question when does it start making boost?

[Gaz6002]

Sorry last question when does it start making boost?

 

I honestly can't remember mate, but it spools really nicely. Not too aggressive, and it pulls like a train.

[Steve]

I may have a 88/75 with a 1.0 a/r divided housing for sale if you are interested.

[Luxluc]

Sorry last question when does it start making boost?

 

That's difficult to say as it depends on what gear you're in.

 

My 91-79 twin scroll makes 1 bar just below 3.7k in 6th, and full boost just below 4k. In 3rd however, full boost only comes around 4.5-4.6k.

Keep in mind that I'm on 264 cams ... stock cams would move the curve more to the left.

 

Luc