Well I finally dynoed the Iroc. It has a ZZ3 crate motor. I swapped out the heads for Edelbrock 6085 aluminum ones. And installed a TPIS ZZ9 cam. Its a full roller motor too.
It has the stock intake manifold setup, though. It is totally stock, with the 48mm TB.
I also have a 6-speed tranny, and 4.10 rearend.

It dynoed a disappointing 254rwhp/347rwtq.
Does that even sound right? It's got no horsepower

I just need some opinions on this. Or if anyone else has dynoed with the stock TPI setup, please share the results.

Thnaks!

Jason

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AKA Pony Punisher II on all other boards.

89' Iroc-Z
ZZ3 short block-355 TPI ZZ9 cam
NOS 150 shot.
blah...blah...blah..
95' T-56, 6-speed
99' Z' rearend w/ 4.10's
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1997 black Trans AM
A4, bone stock except for the Flowmaster.

 

stock manifold? there's your answer. get a better manifold and a bigger tb. your hp will come way up, i bet.

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

 

I am going tomorrow to dyno a similar setup, and I will be posting results. To be totally honest I am expecting similar results to yours. You didnt say if it has headers or not. Basically, you choke the intake (with the TPI) and choke the exhaust (or maybe not) and I dont care what you do inbetween the results will be limited by one or both of the intake and exhaust.
In a few days after that I am going to go back to the dyno with a... well... its a modified stock intake, and see what sort of difference if any that I get.

 

I was pretty disappointed with my cars results also. I will be switching to a aftermarket computer in hopes that it is my bottleneck. If I were you I would invest in some way (aftermarket ecm or burning chips) to tune the setup before messing with the intake.

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87z 383,afr 190's, crane hyd roller(224/230-.509/.528,112 sep),Ported and polished mini ram, 30lb inj, 3.42 gears, strange 12 bolt, tremec 5spd, , 1,3/4" slp headers.

 

your exhaust is way too restrictive, even more so than the intake, so fix the exhaust first.
You also have way way too much gearing for a TPI car.

 

That's not too bad... my carbed 400 with factory heads (not 400 ones but factory just the same), when it had a Comp XE274H in it and a Performer not RPM and the 305 HO air cleaner, only did 284 HP and 373 ft-lbs. The guys at the dyno were freaked because it was a lousy dyno day; some guy with a 454 with a Comp 302 solid only did like 310 HP and 330 ft-lbs, and everybody was like "that lame-a** small-block with a factory 305 air cleaner on it out torqued a big block!!!"

You're really suffering with that stock intake. But rest assured, your trans and rear end have nothing to do with what the dyno will show your engine's numbers at. Your numbers sound about right for what you've got. Horsepower is determined by flow, pure and simple; molecules per second = work per second. When you uncork your intake to where your motor can move some more molecules it will put up bigger HP numbers.

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

 

ok let me clear some thing up here. I have Edelbrock headers, and full 3" exhaust, and basically all bolt ons that you can get.
I am thinking a Miniram should free up a good 80 hp or so. Oh yeh, and I also have a custom PROM made just for my combo. I think I should also get a bigger cam than the ZZ9. I was thinking af the GM847 with 234/242 duration @ .050 and .539/.558 lift. That would go good with the Miniram.

The ODB: Actually 4.10 gears go VERY well with the T56 6-speed trans.

Thnx everyone!!

 

Yeah, u gotta do some mods to those restrictions. If u have a stock TPI on there its going to not be as much as u want. Mod the airbox, get some AS&M runners, port the plenum, and AFPR.

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Looking For:

87 IROC-Z 350 TPI
84 TRANS AM 305 H.O.

 

dump the tpi and get a carb it actally produces hp!! without spending your lifes fortune!!!

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1989 firebird formula

Mods: converted from T.B.I. to a carburator 305 to a 350. Flowmater exhaust,hedman shortie hedders,202 160 (882) heads,.447/.447 lift 222@.050 duration speed pro 327/350hp cam 350 .40 over (356) Edlebrock torker2 and a 600 edlebrock manual choke (1405)

Future mods performer rpm air gap intake (polished) comp roller cam, and way better headsa 400 defintely in the works!

 

Some of us are making good power with a stock TPI intake (ported) and a ZZ4 engine... Not everyone can do carb, because of emissions laws, and not everyone wants to.

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West Coast GM Shootout 2001!
1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

 

Exhaust should always be done with before intake, cam and heads.

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission
Borg Warner 7.75" 9 Bolt Rear End

Current Mods: LT4 Hot Cam, Comp Cams 1.52:1 Roller Rocker Arms, Edelbrock TES 1 5/8" Headers, Hooker 3" Aerochamber Cat-Back System, Performance Resource Chip, Accel Ignition Coil, Cap, Rotor, 8.8mm Wires, K&N Filters, JET TPI Air Foil, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET (w/o LT4 cam): 14.32 @ 97.7mph
(corrected for elevation)

7.5" 10 Bolt with 3.42s soon to come!

 

what kind of #s did your car post 87-Zya? Im kind of curious what kind of dyno #s turn what kind of ET's. Its like 1/2 the board know their RWHP and the other half knows their ET!

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91 RS W/carbed 350, Vortec heads, performer rpm, Comp cams Xtreme energy 224/230 duration and .477/.480 lift. BFG Drag radials. 3.42 posi,Corvette servoed 700r4, ****ty stock converter. Edelbrock TES, 3inch cat, flowmaster with single 2.5 inch exit.
13.24@104

 

Not to depress you, but for comparison when I still had my stock block L98 (stock cam/pistons/crank/bore)w/ TF heads & Edelbrock base, I turned 271 RWHP/345RWTQ. Power fell like a rock at 46oo rpm. At HRP, this was consistent 13.4's @101. Car was flat on top end. 60' times were consistent 1.91'-1.93's.

I would expect more out of the ZZ9 cam. How was it installed, straight up or advanced?

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KevinP92Z
92 Z28 383 SLP cam,SLP headers,SLP 2ontheLeft,Trick Flow TW heads & pistons,Edelbrock base,Accel SuperRam,52mmTB,Scat Crank & forged ConnRods,MSD 6AL,SLP convertor,Baer 13/12" Track,Moser axles,Hotchkis,Genuine GM 3.42s,SLP HD Torsen,17x9" chrome SS rims
96T/A w/SLP Ram Air,SLP 2ontheLeft, Bilsteins, Baer, Hotchkis, Genuine GM, Torsen
76 4X4 Blazer 400TPI project

[This message has been edited by KevinP92Z (edited February 06, 2001).]

 

you just have to relieze that the stock tpi units weren't designed to make HP at high rpm's. they were designed to be most effective at midrange. if you have a MAF sensor then remove the two screens at each end, also open up the airbox as much as you can. it will make a world of difference. an adjustable fuel pressure regulator will amaze you too. check out the site i am posting, you will learn alot from it. www.racer-x.f2s.com

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have a beat to hell 87 GTA 305ci 700r4
t-tops,recaro,honeycomb wheels,digital dash
paid $600 at a junkyard for it (i had to save it)

 

Ok, got my pathetic results:

237hp@4900
267(yea, you read that right)tq@3500
Have a slight problem with the right bank, something isnt right. The header was way too hot. Im not sure if its a lack of fuel (I doubt) or the y pipe connection, which is a piece of crap.

 

With stock intake, l98 cam afr's, auto trans. stock 87 ex manifolds,273gears. my car rear wheeled at 275hp 312tq and ran like a 13.6 @103. Put on miniram 58 holleytb, slp headers, crane cam. tremec, 342's. 325hp,332tq runs 12.96@108 on motor.

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87z 383,afr 190's, crane hyd roller(224/230-.509/.528,112 sep),Ported and polished mini ram, 30lb inj, 3.42 gears, strange 12 bolt, tremec 5spd, , 1,3/4" slp headers.

 

Well, thanx for all the replies. I really don't feel so bad now, especially after seeing your results...madmax...j/k

Guess it's time for a Miniram