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What to modify next?

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Old Jan 20, 2007 | 08:47 AM
  #1  
DAVEY420's Avatar
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From: Trevose,PA
Car: 85 IROC Z
Engine: 350 TPI
Transmission: TCI TH350 TCI 2400 STALL
Axle/Gears: 3.42 WORN OUT POSI
What to modify next?

Hey guys I'm looking for some input as to what I should mod next. I don't have lots of money but I'm lookin at around 500-700 bucks. What I have is the gm crate 350/290hp motor with my stock tpi on top. It's in my 85 IROC with a/t and 3.42 posi rear. It has Dynomax cat back, hollowed cat, bbk afpr, venom 24lb injectors, K & N filters, tb bypass, air foil, msd coil, high pressure carter fuel pump, 180 thermo and painless adjustable fan switch, and a prom by LSRACING chips. The car is quick but with all the money I've put in it dosen't seem like its running where it should be. So my question is what should I do next before throwing more money at it? Thanks.
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Old Jan 20, 2007 | 11:48 AM
  #2  
Bluejae's Avatar
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From: Topeka, Kansas
Car: 1988 Formula 350
Engine: L98 350 TPI
Transmission: 700-R4
I'd say purchase some suspension components. It may not increase your power, but your ride might feel better and make your car more overall satisfying to you.
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Old Jan 20, 2007 | 12:19 PM
  #3  
DAVEY420's Avatar
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From: Trevose,PA
Car: 85 IROC Z
Engine: 350 TPI
Transmission: TCI TH350 TCI 2400 STALL
Axle/Gears: 3.42 WORN OUT POSI
Sorry I forgot to add that I do have some poly bushings on the swaybars and link. They definatly made it stability a lot better. It has 8 month old struts/shocks and mounting plates too. Thank you. I was thinking maybe headers next?
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Old Jan 20, 2007 | 02:15 PM
  #4  
doc's Avatar
doc
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Joined: Jul 1999
Posts: 2,149
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From: Mims, Florida
Car: '87 IROCZ
Engine: 395 ZZ4
Transmission: ProBuilt 700R4
Axle/Gears: 9 bolt 3.70s
Well, its too easy to spend someone elses money. Here are my suggestions for more speed:
1) Accel or Edelbrock "large mouth" intake manifold,
2) Large tube runners,
3) 1.6 ratio roller tip rocker arms.

I may have blown your budget. But for a 350, the stock TPI is very restrictive. The TPI factory stuff was orinally designed for the 305. Then when GM brought the 350 back, they slapped the same TPI on it.

Next step would be headers.
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Old Jan 22, 2007 | 09:06 AM
  #5  
DAVEY420's Avatar
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From: Trevose,PA
Car: 85 IROC Z
Engine: 350 TPI
Transmission: TCI TH350 TCI 2400 STALL
Axle/Gears: 3.42 WORN OUT POSI
Yeah I was thinkin of upgrading the intake and runners but I have heard that the heads that came on the crate motor are junk. And I don't want to take it apart and then have to do it again. Thats why I was thinkin headers next while I save for heads. Any input? Thanks.
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Old Jan 29, 2007 | 10:24 PM
  #6  
Nitsuj86Iroc's Avatar
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Joined: Oct 2004
Posts: 270
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From: Mantua, Ohio
Car: 86 Camaro Iroc-Z
Engine: 305ci TPI
Transmission: 700R4
definitly big headers, otherwise your cat-back is not really getting a chance to shine.

id say that exhaust and intake should be the first things to put money into, then some heads and cam. id recommend Hooker headers, i like mine
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Old Jan 30, 2007 | 09:52 PM
  #7  
LB9GTA's Avatar
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From: Manitoba
Car: '91 GTA
Engine: 421sbc
Transmission: Powerglide
Axle/Gears: Ford 9" with 3.89
You say that your car seems slow.
Have you taken it to a track?
What did you run?
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Old Jan 31, 2007 | 02:33 PM
  #8  
DAVEY420's Avatar
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From: Trevose,PA
Car: 85 IROC Z
Engine: 350 TPI
Transmission: TCI TH350 TCI 2400 STALL
Axle/Gears: 3.42 WORN OUT POSI
Nah I have never been to a track yet. I'm just judging by the few races I've had on the street, like my buddies 97 T/A and from a dig it's even till about 70 then he pulls away. Same with the newer wrx's I can play to a point then I get pulled. I know I need to do more I just want to do it right so I don't put a mod on and it feel worse. Thanks.
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Old Feb 21, 2007 | 03:49 PM
  #9  
rocluvr0013's Avatar
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Joined: Sep 2004
Posts: 765
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From: Chico/Antioch California
Car: 1989 iroc Z Hardtop
Engine: 350 tpi
Transmission: 700r4
headers Y pipe (the stock stuff is JUNK)

stall 2400-2800 would be decent on the street.

and go to town with a dremel on that tpi manifold. Thats definitely a restriction on your 350. Anything you can do to increase flow here is going to help.

I would say if your serious about making power that instead of spending big money on a better LTR setup i would port stock stuff and save for a HSR or similar manifold. (unless you really like the tpi intake mani some people certainly do)
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Old Feb 21, 2007 | 07:12 PM
  #10  
gta31's Avatar
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Joined: Mar 2006
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From: pittsburgh
Car: 87 gta
Engine: l98
Originally Posted by obehave8802
Is your stock tpi polished? My boyfriend polishes, port matches and powdercoats tpi setups for a pretty reasonable price if you're interested in doing that...

Steph
www.robiecustoms.com
i hate this **** on every forum that comes up about any kind of engine work
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Old Feb 21, 2007 | 07:35 PM
  #11  
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From: south Louisiana
Car: 1985 Z28
Engine: 85 L98
Transmission: 700r4
Axle/Gears: stock 10 bolt-3.73 eaten posi
Originally Posted by rocluvr0013
headers Y pipe (the stock stuff is JUNK)

stall 2400-2800 would be decent on the street.

and go to town with a dremel on that tpi manifold. Thats definitely a restriction on your 350. Anything you can do to increase flow here is going to help.

I would say if your serious about making power that instead of spending big money on a better LTR setup i would port stock stuff and save for a HSR or similar manifold. (unless you really like the tpi intake mani some people certainly do)

id look into either the edlbrock headers and ypipe or the hooker supercomps with ypipe. and then the cat-back.
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Old Feb 22, 2007 | 08:52 AM
  #12  
DAVEY420's Avatar
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From: Trevose,PA
Car: 85 IROC Z
Engine: 350 TPI
Transmission: TCI TH350 TCI 2400 STALL
Axle/Gears: 3.42 WORN OUT POSI
Thanks everyone for your input. Looks like I'll purchase some headers and y-pipe soon.
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