ok guys i want to know what you think, i have a 400 small block in my garage, had about 60,000 miles on it when pulled, all stock, factory forged crank, I have been playing with ideas about what to do with this thing, how i should build it, my iroc currently has a 305 tpi in it and a 5spd, i would like to stay with Fuel injection, and/or the stock TPI if i can, so i want to know what you guys think i should do with this thing, also workin on a small budget so im tryin 2 keep it affordable,

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87 IROC-z 305 TPI 5spd Borg warner 9-bolt 3.45 posi 4 wheel disc,8.8 Accel wires , bosch platinum +4 plugs,gutted air box,k&n oil filter,synthetic oil 10w30

 

i didn't know 400 came from gm with forged cranks, guess i learned soemthing today. i wouldn't use the srock tpi set up. and if i was working on a limited budget i tihnk i might wait untill i had more, or just do a little at a time, but do it "right".

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ICON Motorsports

1st & 3rd

[This message has been edited by ede (edited February 03, 2001).]

 

Well, since "everyone" is supposed to respond to this, I'll put my oar in the water.

The #1, absolutely worst, without question biggest performance restriction to the factory 400's was the heads. Get something aftermarket to wake that baby up.

Next thing, #2, couldn't-be-much-worse-restriction-on-performance was the cam.

After that, intake, but you're taking care of that with your TPI. But then, with new heads & cam that 400 will breathe a lot heavier than your 305, so that'll need upgrading.

Of course, you wouldn't even think of starting this without headers, high-flow cat & cat-back, right?

Synthetic oil assummed...

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R. 2.93 limited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/LB9 block, ZZ3 cam and intake, WP 305 heads ported & polished, Hooker headers & y-pipe, hi-flow cat).
57 Bel Air, my 1st car. 0.030 over 396, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

[This message has been edited by five7kid (edited February 03, 2001).]

 

Both ede and five7 are right: no factory forged 400 crank ever (should be a 509 casting), 882 smog crap heads, and the old .390"/.410" cam. That cam & head combo was responsible for holding the mid-late 70s 350s to 185 HP.

A stock TPI will run out of breath at around 4000-4200 on a 400. Work it out: if it falls on its face at 5200 on a 305, and you put 33% more inches under it, the flow will support 33% less RPM. Of course, you'll have great torwue, with a peak at about 3400 RPM, and max HP at 4000 or so, so the engine will run like a truck: big grunt off the line, run up to the brick wall, and feel like you hit a governor.

The 400 IMHO is a great motor if you get good flowing heads and put a real cam in it, but TPI doesn't cut it. I have a carb on mine and would suggest you consider the same if you local laws allow it.

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"So many Mustangs, so little time..."
ICON Motorsports

 

ok guys, about the crank, I know it is not a cast crank,so maybe its not a factory crank, its definitely a forged crank, as for the TPI setup, if i put in a good cam, and head combo,ported plenum,siamesed or large tube runners ported or aftermarket base, 58MM Throttle Body with airfoil, 22Lb Injectors,Ram Air setup,K&N filters,and of course an AFPR cranked up all the way to feed it enough fuel,and for the brain a 350 computer,aftermarket or custom chip/prom
and a pair of headers with a 3-Inch Exhaust .

with those mods what do you think the engine will run like with that setup?


thanks for the replies sorry mine are so long.

 

Say "miniram", "24 lb injectors", "custom PROM". Now you're getting somewhere...

 

Of course your "small budget" is now saying "ouch!".

 

They are correct, it's all about airflow, I wouldn't even consider TPI on a 400, miniram......

 

i agree with the other guys on the TPI thing. that manifold was designed for a 305 and never really ran worth a crap on the 350s. Settle down, TPI guys, if yours runs hard, you have done considerable mods to it. that was one of the reasons chevy went to the lt1. check your smog laws and try to go for a carb. otherwise, an lt1 400 would be pretty cool, but small budgets don't really lend themselves to pretty cool ideas very often.

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88 S10
Dropped 3/4
Dart equipped 406
12.20 @ 115.25 mph

 

ok one more question, i have seen people with 383 Tpi setups working very well, and thats not too far off, i dont want the TPI to be my final setup, however i would like to be able to run this car , even if its not gonna be the best out there , it is my daily driver,and until i get the money to do a mini ram or a super ram, i will have to drive something, also will a borg warner t-56 hold up to the power this motor will be making with a mini ram? thanks a million guys... keep em comin

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87 IROC-z 305 TPI 5spd Borg warner 9-bolt 3.45 posi 4 wheel disc,8.8 Accel wires , bosch platinum +4 plugs,gutted air box,k&n oil filter,synthetic oil 10w30

 

wow man...ur a early riser....6:54.
anyways...i personally am goin with the Accel DFI, AFR 210s, might stroke it and/or bore it, cant decide....$$$$, Hooker 1 3/4 LTs, not sure bout the cam, anyways....good luck....and RB83L69 is the man to talk to about 400s

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Rick
90 Camaro RS 305 TBI
400 small block, Hooker 1 3/4 LTs, Random Tech Cat, Hooker aero chamber cat back on the way!!
TH700-R4 with Trans-Go shift kit (corvette servo here...but not installed yet)
MacEwen Motorsports White Gauge Overlays
14" K&N X-Stream Open Element
GTS Headlight and Taillight covers
5% Limo Tint all around
Classic White Chevy Bowtie sticker on rear window
http://www.geocities.com/esvalenz

Man if my camaro were a rice-rocket all those mods would give me what...easily 50-60 hp!!!

"Just because I've done it, doesn't mean I knew what I was doing!" - Me