scamaro355

Ok I've spent the past 1.5 hours in search and have gotten fed up so I'm just gonna ask. I need to order an intercooler for a single t76 setup. Im wanting to go with a 3" core. The issue I'm having is dimensions.. Most im seeing are 26x12x3 to 31x18x3. Im out of town and would love to have this waiting on me when i get home in a few weeks. Any help appreciated. Thanks!

86trbota

How much power are you trying to make and what fuel?

86trbota

http://m.ebay.com/itm/360493556623?cmd=VIDESC
I have heard nothing but good thing about mishimoto from my diesel buddies. I think you should be able to make this fit and a lifetime warranty. also a great price or just do the ebay cheapo that everybody on budget builds use.

scamaro355

Im shooting for the 750+ rwhp on pump gas with meth. The engine is a dart headed 355 with a stealthram. 9.2:1 compession. Fully forged rotating assembly. Arp studs on mains and heads

scamaro355

Mishimoto. Ill look into them thanks. Alot of ppl keep sending me cx racing

anesthes

iTrader: (12)

750 wheel horsepower with a single T76?

I don't think so.

-- Joe

scamaro355

Ok then give me a direction to make my goals.. This is my first turbo build.

anesthes

iTrader: (12)

Probably a T88 or something similar.

I went with a single T76 as well, and it was a dumb move. On a 305 or a 350 the T76 is a great small turbo. It really shines on a low-flowing engine - something that can make 14-20psi at 60-70lbs/hr airflow.

On a free flowing 355, and especially my race-prepped 412 we're spinning the thing WAY too much, way out of the efficient zone, etc.

But anyway, to fit a T88 under the hood would be an epic challenge. The next challenge is routing the required 4" downpipe.

Knowing what I do know, to make a 700+ wheel HP turbo small block requires two smaller turbos, dual 3" downpipes.


-- Joe

scamaro355

Ok thanks for the info. Time to do some thinking...

Orr89RocZ

iTrader: (20)

Treadstone works well. You really need to have it layed out and measured exactly to fit how you need it. But generally between the front frame rails, a 24" x 12 will work fine.
Mines 25x9x3.5 core and fits good

Single 76mm could support the numbers but depends on wheel specs. 76 inducer only tells part of the story. Guys make 1000 on borg warners s475-476 billet wheels. 1200 on an 480 billet. 364-370" motors. Also depends on trans. Autos are more difficult

scamaro355

Ok i was thinking i had seen ppl making good power with those. The trans is a 4l80e. So i know its gonna cost me some power. But at least it will last

Orr89RocZ

iTrader: (20)

Well have you bought the turbo yet?

scamaro355

Nope not yet. Just got done stripping the engine bay to bare metal and primed painting it thursday. I had planned on running n/a for the summer and the turbo was gonna be a winter project. Then i decided i just as well do it while its all apart

86trbota

If your lookin to make that much power I would look at some of the t4 borg warner stuff. Like a s476r that should easily do what you want.

scamaro355

Ok thanks ill see what i can find on it

anesthes

iTrader: (12)

When he says "T76" I'm assuming he means literally, a Turbonetics T76 or clone like I'm running:



For 750 WHP, he needs a minimum of 99lbs/hr airflow.

99lbs/hr on a 355 should be around 22 psi (2.5 pressure ratio).

The T76 has a max of 93lbs hr, so he's short there.

At 2.5 ratio, if you intersect at 93lbs/hr you are WAY off the island.


With a T88:



At 2.5 ratio and 99lbs/hr, he's right on the edge of the 78% efficiency part of the island.

A BW S476 wouldn't be a good match either, but would better than a stock T76:



He would be kinda-sorta on the island, but would still be in the horrible efficiency zone.

Like I said before, if I had "got" this stuff early on, I would have went twins. Once I got a handle on reading compressor maps I realized how tricky sizing a single turbo to a big engine is in the small engine compartment of a thirdgen.

-- Joe

Orr89RocZ

iTrader: (20)

Yeah its edgey but does work because many have results showing those turbos will make the numbers. They are best with 4.8-5.3's over 6.0's but still can work.

Billet wheel 76 doesnt flow quite like the common maps you find for the s400 base. Its getting harder to find maps these days and companies dont seem to release them

Your generic T76 name i also think of the basic T4 designs, the knockoffs included. S400 wheels are much larger in the back end

A good 355 with heads cam should do 750 whp with abit less than 22 psi tho.
Twins is always a good idea for big numbers in tight bays

scamaro355

What confuses me about picking a turbo and talking about the maps is how can you compare a stock engine to one with a good set of heads,intake cam headers.. I understand the cubic inch half of it. But the volume of air a well built engine will flow compared to a stock engine is a huge difference.

Orr89RocZ

iTrader: (20)

Its simple. Heads cam engine flows more and makes more power than a stocker. This changes the base hp load you are working with, which thus changes pressure ratio you need to hit your desired boost goal.

Make as much hp as you can on motor and then add boost has been a successful built guideline. Making 750 whp on a 300 hp base engine is harder than same power on a 450 hp engine. My preference is to run as little boost as possible. Less air compressed means cooler temps so intercooler doesnt need to work as hard. This means you can get away with cheaper coolers and save some money, or even eliminate need for meth inj but thats a good idea on most all setups with higher boosts

anesthes

iTrader: (12)

It's actually very easy. It's called volumetric efficiency. I made an educated guess at how 'free flowing' your 355 is. I could be off, but that only matters as it determines my calculated pressure ratio.

You still need the same lb/hr airflow to make your desired horsepower. And really, the difference between 2.2 and 2.7 on the pressure ratio isn't that much when you intersect with the 100 lb/hr column in regards to where on the island you land.

If you had a stock L98 with an emissions cam you will make more psi than a free flowing 355 for the same airflow. A T88 on my 412 would be just perfect, and I suspect it would be perfect for yours too. The BW would work as Orr suggested, but not as good as the T88. When I say T88 I mean a real one, so when comparing knock offs make sure both wheels and both housings are the same sizes.

-- Joe

scamaro355

Thanks guys.. This gives me alot to think about