Jc803

iTrader: (2)

No one is commenting on any of my other posts so I'll try again with less questions.
Everyone is saying a t4 flange is too much backpressure, and I'm not arguing.

1. Is it possible to cut the t4 flange off and weld on a t6, or do I need all new piping?

2. Even if t4 is too much backpressure, how much power could I still get? I'm making just over 500 all motor as is. Could I do t4 turbo and change cam and anything else and make about 700?

3. If keeping the t4 flange to make 700 or more is better than changing to t6 flange, then what t4 turbo would you recommend?

Pat-Man

iTrader: (3)

408 over here rocking a T4 flanged T76 turbo. You won't be able to just change your T4 to a T6. You have to get a larger turbo, say a GT-88,91 that has a T6 frame. Larger turbo means you will have to change out most if not all of your piping, cold and hot side.

stevieturbo

If you're only looking to make 700hp, then there is nothing wrong with a T4 flange.

There are people making 4 figures with T4 singles.

Jc803

iTrader: (2)

Thanks guys that just what I wanted to hear. I also PM'd Superman @ Huron speed and he pretty much said the same thing. He said I could get 800 but hell I'd be happy with 700. I also went back and re read the Rogue Missle article in GMHTP and that guy was making 850 on his t4 before he switched to t6.

I can fab up a larger downpipe no problem. But I have a 44mm wastegate flange. Would you guys cut that one off and add a larger or add a second 44mm flange?

Jc803

iTrader: (2)

What size turbo would you guys recommend. I've been recommended either the t7875 or 7575 with 1.15 a/r. Any thoughts?

And as far as water cooling, how would I run the lines. I've already removed the heater core and have the inlet and outlet on pump capped off. Could I just use those to run lines?

DEFYANT

Borg Warner S480 with a T4 flange... And the biggest A/R and exhaust wheel possible... 408 is big for a T4 flange.

Sarg

iTrader: (6)

What is the turbo piping made to fit currently. Depending on placement and such, it may not be too terribly difficult to just modify the piping and go T6. T6 Borgs are cheaper and better suited to that size motor. You could go with an off the shelf S480 T6 1.32 AR with the 96mm turbine for like $900 and be able to make over 1000 hp to the wheels if you choose, or turn it down and make your 700 easily.

It's just metal, make it do what you want!

Jc803

iTrader: (2)

Which s480. I'm sorry but I'm new to FI so feel free to talk to me like a child.

Piping is the Huron speed single kit without AC. 2.5" crossover, 3" downpipe, 3" cold side, 50mm bov, and I got the optional 44mm wastegate flange.

I can fabricate a downpipe no problem. I could fabricate everything really I'd just rather not because I live in an apartment. So I'm just seeing what I can do with what I have and trying to get ideas. I'm making 511 rwhp last dyno all motor. I only want to make 700-800. Trying to figure out if its possible with what I have

Jc803

iTrader: (2)

Also I like staying away from fabricating as much as possible because I have a really crappy flux core welder

Edit: lol Sarg I was just searching all of this and was reading a few threads with you in it and I just noticed you're the one that commented. I'm glad, you seem to know what you're talking about.

Also, like I said I have a welder and $13k in tools (ex ASE cert mechanic) and I've relocated battery to rear, removed all AC and heat, front sway bar, and ABS block is about to go next, so Ihave plenty of room so anyone feel free to throw me some ideas

Sarg

iTrader: (6)

Ah, the only down side (no pun intended) to that kit is a 3" downpipe. The T6 turbos are going to be a good bit larger...like 5" downpipe. Now on mine, I reduced it to 4 inch and I really don't think it is going to kill it much at all. Heck there are people out there like MM that ran 3.5" and killed it! But at 3inch you are really going to choke things up a good bit on that 408 IMHO.

The crossover is probably plenty big. But if you are trying to stay away from fabricating, I would make a mock of whatever turbo you plan to get and set it down in there. Even if it is just out of cardboard and is roughly the same size. Some kits are specifically designed around a certain size turbo and if you don't want to try to modify it, they may or may not work.

I don't have experience with any of the "kits" that are out there. I just chopped mandrel bends and tigged it all up after teaching myself to tig weld, lol. I had done a good bit of mig, but tig was new. I wanted to do stainless and really liked the precision of tig welding. BTW, I started with a $500 chinese tig welder/plasma cutter that I still use 2 years later. It has its limitations (like no AC, so no aluminum welding) but it works.

I donno man, if you are not wanting to fabricate it is kinda gonna be a crap shoot as to what might fit there. Maybe check with Dr. Turbo and get the dimensions of some of his turbos that he offers.

stock48

iTrader: (17)

Either a PT88 or new BW S476/96 1.25 in the T4 housing if you have room. The T4 will work but you need to keep rpm below 6k.

Sarg

iTrader: (6)

The compressor cover on the S476 is still going to be quite large though isn't it?

Sarg

iTrader: (6)

S480 with my 110 lb wife for size comparison, hehe.

Jc803

iTrader: (2)

No no. I'm ok with fabricating. I already know 90% chance I'm going to have to fab up a 4 or 5" downpipe. What I ment was I'm not too sure about the cross over like switching to a t6 flange, and I'm pretty sure I'm going to have to add a second wastegate flange or larger single (havent thought that far yet).

That s480 is massive. But I'm sure I can fit it. But with the t4 flange would I even benifit from something that large? Seems like the flange would peak out way before the turbo. Of all the turbos recommended here, what would be the best, regardless of downpipe size or space available.

One more question, the cold side piping and intercooler is 3". Would that be ok or should I plan on fabing new piping.....and maybe a tig welder...

Jc803

iTrader: (2)

Actually, I think I'm getting ahead of myself. Going back to the t7575. Correct me if I'm wrong, but it would bolt right up to my 3" downpipe, and 3" cold side. I mean I would still have to add a second wastegate I think. And I can get a good deal on one.

So how much power do you guys think I could get with that? I already have AFR 225 heads, FAST 90, 90mm TB, and everything else in my sig. Making just over 500 now. Any idea what it could make?

Sarg

iTrader: (6)

Honestly, I would do it once and avoid having to buy parts twice. The compressor outlet on the s480 is a 3" outlet. Get the s480 with the 96mm turbine and 1.32 ar turbine housing and it is only like $900 brand new! That is an easy 900 hp turbo on your set up without breaking a sweat. Add an additional 44mm wastegate and you are set. That 7575 is going to choke out quick imho. The guys at Forced Inductions are rumored to be working on a larger turbine for the s480 that should be offered as an upgrade later. You can also do a billet 80 wheel later if you get tires of the cast one. Just my thoughts.

Sarg

iTrader: (6)

Oh and switching to the t6 flange is as easy as cutting off one flange and welding on a new one. Maybe some bracing but that is about it. You may have to rearrange things a bit to make room for the larger turbo and downpipe though.

Twin turbo c5

If 700 is all your after it'll be fine . My t4 flange s480 was on my friends 408 before I got it. It ran 7.80's in the 1000 foot in a 2001 Camaro with ac and full interior. So I would roll with what you got for awhile and maybe upgrade later.

Jc803

iTrader: (2)

@ Sarg, is the compressor outlet a 3" on both the t4 and t6 flange s480? Where do you guys find this stuff, I cant find specs to save my life. And that means my cold side piping and intercooler will still fit right? Just have to make a larger downpipe? As for switching to the t6 flange I'm going to order one off amazon just to check out how hard it will be to fit and see what I can do.

@ Twin turbo c5, by "it'll be fine" are you refering to the t7575 or s480?

Jc803

iTrader: (2)

Found it. T6 is also a 3" outlet. Now this sounds like a plan with minimal fabricating and most cost effective. Seems like I just have to make downpipe, add another wastegate, and put on a t6 flange. I'm glad I dont have to mess with the cold side because no way my welder will do aluminum