Turbo size for a 402???

Reply Subscribe

Thread Tools

Search this Thread

Feb 14, 2006 | 08:11 PM

#41

2001-WS6

9 Second Club

Joined: Feb 2002

Posts: 985

Likes: 7

From: Lake Orion, MI

Quote:

Originally Posted by JZ 97 SS 1500

The turbine wheel (R-trim) though nice flowing is still to small.

Could it be better? Yes.

Can it still support mid to low 9s passes? Yes.

Rick

Feb 15, 2006 | 07:52 AM

#42

SSblack98

Thread Starter

TECH Regular

iTrader: (8)

Joined: Nov 2004

Posts: 420

Likes: 0

Quote:

Originally Posted by PurEvl

my car has never had race gas..yet...the 818hp was 14psi and 14 timing up top on 93 pump

Holy horse crap! Do you have meth or alcy injection? Your #'s are exactly what I am looking for only I would like to stick with an alum block cause I won't be racing/running high boost alot. What heads are you running? I've read 6.0 heads are ok and AFR 225s are best for boost.

Also, I am about to order up a rotating assembly and need to know what cc pistons I should go with for a 8.5-9:1 comp. Lets just say for now that I will run AFRs. What is the formula for calculating comp based on piston -cc, head cc, and knowing headgasket thickness?

Feb 15, 2006 | 08:28 AM

#43

PurEvl

TECH Senior Member

iTrader: (2)

Joined: Mar 2002

Posts: 5,469

Likes: 0

From: South of Heaven

i have nothing but pump gas, i dont use meth or alky and probably never will. I will put race gas in it for the first time ever when i go for 4 digits

I got the outlaw iron 408 from combination motorsports..its built for 1400hp(estimate of course). I have -24cc dish pistons with afr 225 heads untouched...im about 8:5:1

This motor with a 218/230 cam with 571 lift on a 116 made 432hp 450tq natural

Feb 15, 2006 | 08:39 AM

#44

RealQuick

TECH Junkie

iTrader: (14)

Joined: Feb 2004

Posts: 3,970

Likes: 15

From: MA

I am going to be doing a GT42-76 with a T6 for my 383ci LT1....

Feb 15, 2006 | 09:37 AM

#45

PurEvl

TECH Senior Member

iTrader: (2)

Joined: Mar 2002

Posts: 5,469

Likes: 0

From: South of Heaven

Quote:

Originally Posted by RealQuick

I am going to be doing a GT42-76 with a T6 for my 383ci LT1....

by the time its done...turbos wont be used anymore...we will all be onto laser beams an ****

Feb 15, 2006 | 09:38 AM

#46

SSblack98

Thread Starter

TECH Regular

iTrader: (8)

Joined: Nov 2004

Posts: 420

Likes: 0

Quote:

Originally Posted by PurEvl

That seems like an awfully small cam for a 408. I was thinking of like a 235/230, 600ish lift 114-115 lsa cam for my 402. I thought turbos like a reverse split though I know it depends on your exhaust/intake efficiency. Is that too big a cam for a turbo 402? You must have a great header design to be running that much duration on the exhaust. That thing must idle and drive like stock!

Feb 15, 2006 | 09:42 AM

#47

RealQuick

TECH Junkie

iTrader: (14)

Joined: Feb 2004

Posts: 3,970

Likes: 15

From: MA

Quote:

Originally Posted by PurEvl

by the time its done...turbos wont be used anymore...we will all be onto laser beams an ****

[Chapelle] Cold blooded[/Chapelle]

That hurts Mike... I still want a ride in your beast after that half *** sts ride you gave me.

Feb 15, 2006 | 09:47 AM

#48

SSblack98

Thread Starter

TECH Regular

iTrader: (8)

Joined: Nov 2004

Posts: 420

Likes: 0

What is the difference between a "Tan" A/R and "on center" A/R?

LS1 Tech Stories

The Best V8 Stories One Small Block at Time

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Pouria Savadkouei

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Verdad Gallardo

7 Most Reliable High-Performance Engines GM Has Ever Built

Verdad Gallardo

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Verdad Gallardo

6 Common C5 Corvette Failures and What's Involved In Repairing Them

Pouria Savadkouei

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Verdad Gallardo

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Pouria Savadkouei

Top 10 Most Powerful Chevy Trucks Ever Made!

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Verdad Gallardo

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Verdad Gallardo

Feb 15, 2006 | 09:50 AM

#49

RealQuick

TECH Junkie

iTrader: (14)

Joined: Feb 2004

Posts: 3,970

Likes: 15

From: MA

Quote:

Originally Posted by SSblack98

You must have a great header design to be running that much duration on the exhaust. That thing must idle and drive like stock!

He is using 6.0L truck cast manifolds turned toward the front...so no it isnt a GREAT header design. His stuff wont crack though and flows well enough to make the insane power Mike is making.

Feb 15, 2006 | 10:32 AM

#50

NA$TY-TA

TECH Senior Member

iTrader: (21)

Joined: Aug 2002

Posts: 10,331

Likes: 1

From: San Antonio, TX

From alot of the questions you have been asking it sounds like you need to call up an engine builder and discuss your goals and plans with them and then go from there....
Each persons goals are different...
Discuss with them the Block, Pistons, rods, crank, Heads and Compression.
What Your HP and ET goals and plans with the car is.... How tame you want it to be on the street for daily driving and what not.....
The idea behind his cam is its tame.... he could add cats to the car and pass inspections up there....

Feb 15, 2006 | 10:32 AM

#51

JZ 97 SS 1500

LS1TECH Sponsor

iTrader: (2)

Joined: Aug 2002

Posts: 2,725

Likes: 0

From: Huntsville, AL

Quote:

Originally Posted by SSblack98

What is the difference between a "Tan" A/R and "on center" A/R?

Tangential and Oncenter are just two different types of housings. Nothing more...

Feb 15, 2006 | 12:54 PM

#52

98Z28MASS

TECH Addict

iTrader: (6)

Joined: Jul 2004

Posts: 2,964

Likes: 1

From: Massachusetts

Quote:

Originally Posted by SSblack98

I was speaking of pump gas. I'm hoping for around 650rwhp on 93 octane. Then maybe 750-800 in race form. I have been trying to really research this but it seems like everyone has a different opinion as to turbo size.

Apparantly bigger is better but I'm just trying not to be too rediculous and end up with a turbo that supports 1000+hp when I don't really need it. Am I correct in that a T88 is NOT a ball bearing unit? Is it available as such? I know the BB turbos are salty but I only want to do this once and so I'm thinking BB would be the way to go.

I was speaking of pump gas too lol! As Purevil's car has shown with the right setup you can make 700-800+ rwhp on 93 octane with not alky or meth injection. Plus as eh said he is still using a fairly tame cam and untouched 225 afrs. If you went with a large CC head, say an ETP 240+, and maybe a slightly bigger cam the same numbers could easily be seen on a 402. I say go T-88 and be done with it. If you go with the T-76 it will spool a little quicker but would lack the top end power the T-88 would have an plus would you really want a turbo that would spool sooner? All that will result in is seeing full boost quicker an annihilating your tires, whereas with the T-88 the slightly longer turbo lag would help with traction, especially on the street.

Feb 15, 2006 | 12:55 PM

#53

PurEvl

TECH Senior Member

iTrader: (2)

Joined: Mar 2002

Posts: 5,469

Likes: 0

From: South of Heaven

Quote:

Originally Posted by SSblack98

it idles under stock if you want it to...I put it at stock...it sounds an drives very stock. My clutch is lighter then stock too

Im using truck manifolds so not to sure how great they are but there gm's design

I have had big cams, they idle like ****, they load up, they stink all the time, they buck with the locker alot. Just not for me

Feb 15, 2006 | 07:56 PM

#54

CHRISPY

TECH Senior Member

Joined: Nov 2001

Posts: 10,341

Likes: 1

Pesonally I would forge the 346 (8.8:1) run a 02+ LS6 cam and ETP 215 heads.

Pickup a master power T70 turbo. You'll hit 650 easily on pump and have great spool.

If you want 800RWHP a T76 would work well on 346ci.

If you are 402 I would go with T88 for sure. Spool wont be bad with those big cubes.

Feb 16, 2006 | 07:54 AM

#55

SSblack98

Thread Starter

TECH Regular

iTrader: (8)

Joined: Nov 2004

Posts: 420

Likes: 0

Thanks for all the advice guys.

I think I will likely go forged 402, 8.5:1, AFR 225s, T88 up top, fairly mild cam, 99-up PCM and harness. Engine will be in by spring and hopefully boost it this fall/winter. HiFlo should have everything worked out by then.

Feb 16, 2006 | 09:45 AM

#56

98Z28MASS

TECH Addict

iTrader: (6)

Joined: Jul 2004

Posts: 2,964

Likes: 1

From: Massachusetts

Nice sounds like a sweet combo, def let us know how the build goes and post numbers when you get them!

Feb 16, 2006 | 10:00 AM

#57

RealQuick

TECH Junkie

iTrader: (14)

Joined: Feb 2004

Posts: 3,970

Likes: 15

From: MA

Quote:

Originally Posted by SSblack98

Just be sure the hiflow kit will work with the T88...layout wise.

Feb 16, 2006 | 11:36 AM

#58

Stupid Boost

Launching!

iTrader: (1)

Joined: Jan 2006

Posts: 226

Likes: 0

I think a 402 and 88 have already been done......

Check out this post...

https://ls1tech.com/forums/forced-induction/435980-402-s88-muhahahaaaa.html

Feb 16, 2006 | 11:44 AM

#59

qqwqeqwrqwqtq

FormerVendor

Joined: Dec 2001

Posts: 2,444

Likes: 2

From: WWW.SPEEDINC.COM

As far as using a single T4 turbo, we've had the best results with 346-370ci engines and the GT76 R-trim (1.15a/r) innovative unit. More displacement with that turbo has just equalled excessive backpressure, and a shortened RPM range.

We have a PT76GTS here that we've not yet tested.

Also, the only thing we've seen between the GT80R and the GT76R is more lag. In fact, our highest dynoing car with the TTI race hot parts was 370ci and GT76R turbo. (908rwhp 908rwtq).