Here is the setup I plan on building:

-Rebuilt 355 (machined, balanced, blueprinted, etc.)
-LT4 HOT Cam (possibly 1.6 roller rockers??)
-AFR 190cc heads (possibly 195 cc??)
-SuperRam intake
-58mm throttle body
-Hooker Super Comp Shorty headers (1 5/8"), high flow Catco cat, Flowmaster 3" cat-back
-TCI 2200 Stall Speed torque converter
-700R4 trans
-3.42 posi rear
-Mickey Thompson ET Street slicks
-Adjustable torque arm
-Steel tubular lower control arms with poly bushings
-Sub frame connectors

I already have the headers, exhaust, and torque converter on the car. Will the 1 5/8" primary size hurt me? Will the 2200 stall speed hurt me? Any other comments or suggestions would be greatly appreciated. I'm gunning for 12.2-12.5. Thanks.

 

what about heads? It will help you more than anything else you have listed.
That is if you don't already have a plan for that.

 

nevermind I didn't see the AFRs in your list

sorry

Well than it looks good to me.

 

It's going to be a tall task getting your car to low 12's. A couple of years ago we did a Vette that ran 12.40's with a stock 350 bottom end. We used a LPE 74219 cam, AFR 190 heads, SuperRam, 52mm T-Body, 15/8 headers, no cats, 3.73 gears and Drag Radials.

www.geocities.com/dzperf

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D&Z Performance
"Putting Power to the Pavement"

 

What were the 60' times on that Vette? Thanks.

 

compression!!!
10.5-11:1 the heads are right on. possibly
the brodix track 1.
the primary tubes are too small for 375-
415hp. hog the intake to support more air.
lighten the car 100-200 pounds.
just my opinion

 

I've got AFR 190's, SR, LPE 219, Edelbrock 1 5/8" headers, gutted cat, 3" Flowmaster cat-back, a 2200 stall Vigilante (not installed yet), 3.42 w/ Auburn Pro posi, and a fresh 355 w/ stock crank and rods w/ TRW forged pistons, some suspension goodies, etc., etc., check out the website for everything. I'm hoping for mid 12's once everything is tuned, 315 mm drag radials are on, I get a built tranny, a 52mm tb, and a custom PROM are in. Wish I had some REAL times, but today was the 1st time I have really driven the car more than 2 mins. since it has only been together for a couple days. Never took it over 3500 rpm's. Low 12's is probably asking a little much, although this guys is running 11.5's w/ a similar setup in his C4: http://www.corvetteforum.net/c4/beach_bum/

I will be VERY happy if I run a 12.5 once everything is tweaked. Then comes the nitrous

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89 IROC-To see mods go to: http://www.geocities.com/buckeyeroc

 

The Vette had mid 1.7 60 ft times. Traction was not a problem since he was able to use the 315/35's.

The C4 that you're refering to is a 383 not a 355.

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D&Z Performance
"Putting Power to the Pavement"

 

I've got a VERY mild long tube runner set-up in an '87 Roc. I'm running 12.80's. And my best 60' is 1.67...that's pretty impressive(to me) for all I have in the car...It's all about the combination...here's what I got...

355 cubes with stock bottom end
TPIS ZZ-9 cam
6085 Edelbrock heads(out of the box)
Crane "long-slot" 1.5 stamped steel rockers arms
AS&M LTR's
Stock 48mm TB
TPIS Bigmouth base manifold
AFPR
Accel 300+ digital ignition
TPIS level 5 chip
Edelbrock 1 5/8" headers
3" exhaust
Pro-Built stage 3 700R-4 tranny
Vigilante 2600 converter
stock Borg-Warner 3.27 rear
Poly bushings & STB on an otherwise stock suspension.
Still has the original Bilsteins on it!
Nitto drag radials

Because of my cam and my small gears, the converter actually flashes to around 3200rpm. Precision Industries recommended the 2600 for that reason, and it woks well...very well.
You'll probably need a larger converter than 2200. You want a converter that "flashes" you right into the "meat" of your powerband and I really don't think that a 2200 is going to do that for you.
Call arond and get some profesional opinions about the right converter for your set-up and remember, when it comes to torque converters, just like anything else, money talks. TCI converters are ok, but they are mass-produced and usually not very strong or reliable...it's better to spend twice as much a customized converter now, than to spend half as much on a unit that you'll only be replacing in a short time, hence spending even more...that's my honest opinion.


Personally, I don't see a problem with you churning out some mid-low 12's.
I'm not too familiar with that cam but getting the right cam to match the heads is a very crutial part in making power...best thing to do would be to call AFR and get ther opinion on that cam in conjuction with their 190 heads.

I've heard good and bad things about the LT4 HOT cam. That cam gets it's impressive numbers by using 1.6 rockers.
By using 1.5's it's not that impressive.

In my opinion, I'd go with a bigger cam and start off with 1.5 rockers. If you need more lift, throw a set of 1.6's on.

And definitely stick with the 3.42 rear. The TPI engines don't respond well to steeper gears than that. The TPI's make a bunch of bottom end torque and don't necessarily need a steep gear. Even with a SuperRam, 3.73's may actually hurt your performance and especially if your running a 700R-4. Now if you're in it to just fry the tires, then by all means, get a steep gear...but I really think you'll get more out of your car by staying with 3.42's.


Hope this is of some help to you!
Good luck.

Torq




[This message has been edited by Torq (edited October 04, 2001).]

 

I agree, 3.42's are a good gear for the setup.
I also wondered about the 2200 stall. I called LPE and that was what they recommended so that is what I got. I'll put it in w/ the 2200 to see if I like it or not. But after looking at more of these type of setups, I may send the converter back to get the stall raised, Precision Industries will change the stall for free once in the first year or 2 after purchasing it.

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89 IROC-To see mods go to: http://www.geocities.com/buckeyeroc

 

In Chevy High Performance, they had a long tube setup that went 12.3, so I know low 12s are obtainable naturally aspirated. So is the only thing that is holding me back the size of the 1 5/8" headers? Would it really be worth switching to 1 3/4"? Thanks.

 

Since you already have the 1 5/8 headers keep them, you might lose .05 at the track but your gas mileage will be better.

Stock tb is good up to 5000 rpm in a 350.
58 mm is overkill. Its too big. (others will disagree but look at the guy above with a stock tb).
Since your a little bigger then a 350 and will want a little more then 5000 rpm go with a 52 mm tb. Which is actually a stock 48 mm tb that is bored out. 58 mm is a whole different housing and a lot heavier. To see what you will need as far as flow multiply your cubic inches by the max rpm engine will see and divide that by 2345.

355 x 5200 = 1846000 / 2345 = 787.20...
355 x 5800 = 2059000 / 2345 = 878.03...
355 x 6500 = 2307500 / 2345 = 984.00...

58 mm tb will give you 1000 cfm give or take.

But since I'm an old bald mf my equation is for air/fuel mixture from a carb. The 1000 cfm is for just air. So using a 12/1 air/gas ratio that works out at roughly 92% air and 8% gas. So multiply numbers by .92

5200 = 1846000 / 2345 = 787.20 x .92 ~ 725
5800 = 2059000 / 2345 = 878.03 x .92 ~ 808
6500 = 2307500 / 2345 = 984.00 x .92 ~ 905
7200 = 2556000 / 2345 = 1089.97 x .92 ~ 1002

Don't know much about the SuperRam but if you plan on taking your 355 to 7200 rpm will need a 58mm.

 

Although 3.42 gears is probably the best you could try and find a rear end with 3.23's already in it. If money is an object of concern.

 

Ok, so would the AS&M 54 mm tb be the best choice for what we are discussing here? I need a tb and can't decide between 52, 54, or 58. I'm using the stock one right now, but I also have a MAF sensor w/out screens, will that be my bottleneck and if so, how much is it hurting me?

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89 IROC-To see mods go to: http://www.geocities.com/buckeyeroc

 

I've been thinking about the header primary size issue. Why would 1 5/8" be too small? If you think about it, the primaries only need to bigger than the exhaust valves, and the AFR 190cc exhaust valves are 1.6" (which is smaller than 1.625" headers). Isn't it valve size that determines the size headers you need, not horsepower? Any help would be greatly appreciated. Thanks for all the replies.

 

I don't think that the throttle body is restrictive at all, the stock one on my car isn't holding my car from revving, Its the runners and base. The GMPP ZZ502 fuel injected motor used a production 48mm throttle body like our cars, and it makes 502 HP at 5200 rpm.

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86 Iroc, 383 Ported and polished Sportsman II, stock ported TPI, #24 svo, custom chip, Slp 1 3/4 and 3" Flowmaster, Serpentine with Hypertech Pulleys, Comp Cams roller 218 224, Yank Torque Thruster 2800 3.0, Stage 3 Pro-Built 700R4
98 K2500, True Dual 3", Thorley Headers, 40 series flowmaster, Hypertech power programmer III, K&N cold air

 

Anyone else know about the header issue? Thanks.

 

The headers are a restriction. But a set of 1 3/4 shortys would be to. Shorty headers are a comprimise between packaging and performance. They all neck into a cramped Y-pipe. In short, a switch to a set of 1 3/4 inch shortys *might* get you a tenth but is that worth the $450 it's going to cost you for a set of SLP's ? The preceding has been the authers opinion.

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92Z28
89GTA

 

I would be VERY surprised if the GMPP ZZ502 didn't pick up some power with a larger TB. The volume of air that thing must move would be incredible.

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92Z28
89GTA

 

91 bird. I am pretty sure you pulled those cfm requirements out of your a**.

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1991 Firebird
350 L98 (was a 305 TBI),T-5,Edelbrock TES and cat back,Accel manifold
NOS,subframes,jegster torque arm,MSD Digital 6
AFPR,Lakewood lcas
Hurst linelock,SLP cam (206 212 .480 .486),relocated battery,cold air,Hypertech chip,centerforce df,clutch
poly bushings and mounts
AFR 190s
Harland sharp 1.5 rockers
autopower rollbar

12.33 @ 114.83 juiced uncorrected

13.510 @ 102 non juiced uncorrected