vipershark11

iTrader: (6)

so im getting a 350 tpi motor which im still attempting to get after they tried to screw me by giving me a 305 but thats besides the point. so anyways im going to take the 350 put some procomp 190cc heads which i think i saw flow 250cfm at .500 lift and are aluminum on the block. from there ill be putting in a zz4 cam which is .510 exhaust .474 intake and 210 intake duraction and 220 exhaust roughly on a 112 lobe separation. added to the cam is going to be 1.6 rockers to up the lift even more. for exhaust i have hedman shorty headers and y into a gutted cat with a 2.5" catback. for the intake system i have a ported heavily stock base that will be nicely complimented with slp runners which im going to port to match the base and port the plenum side as much as possible and siamese it maybe halfway in if i can reach that far. added to that would be a ported plenum which has the egr walls removed completely the throttle bores opened up and now the runner dividers will be cut out to match the slp's. to feed that i have a k&n on the factory 89 firebird intake. this is a MAF system and will be tuning it myself. my questions are 1) what size injectors will i need? 2) how much hp do you think itll put out?

joeblue83

iTrader: (8)

30 pound injectors will be enough for your application. I am only running 30 injectors and maintaining 48 pounds the whole way. The thing that will hold you back is the 2.5 catback. I believe stock the car came with 2.75. You might want to look into getting a 3 inch cat instead. I had close to that combo and had 292 rwhp and 320 rwtq

Gunner823

iTrader: (2)

yep..with a slightly larger cam, AFR heads and 4" catback (I'm running that EXACT intake setup by the way, just as you described) I'm putting down 305rwhp and 340rwtq.

Dale

iTrader: (12)

I have a 3" setup all the way on a basically stock motor plus headers.

2.5" is what the v6 runs. That sure will not support a modded 350.

vipershark11

iTrader: (6)

the y pipe from hedman i believe is 2.5" right there so id assume itd be fine since it wouldnt restrict it if the y pipe is already that size.
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btw whats the peak rpms you guys with the ported slps and base with plenum are running with?

1989GTATransAm

iTrader: (3)

To many variables so I will go with 280rwhp.

Orr89RocZ

iTrader: (20)

thats reasonable. stock full bolt on L98's will dyno 250whp +- 6 hp depends

zz4 cam should net 265 i'd say. add heads and abit better compression and you got 280-300whp i'd say

irocz28boy

iTrader: (2)

Exactly..so it will already be restricted at the y-pipe. Since the header collectors are already 3", you should get a 3" y made and then get a full 3" catback. 2.5" is simply not enough.

vipershark11

iTrader: (6)

ill look into the exhaust after i get it all running and dynoed. today i just got my heads in and they look like some badass performers. and tonight im going to order some 30Ib injectors brand new. and also my slp runners should be here tuesday so i can get to porting those and ill probably have my manifold off by then too so i can do that at the same time.

LMSkyliner

iTrader: (1)

seriously. 3" in a minimum. I reccomend 3.5 or 4" for any serious performer, though 3" should be fine for this application, but no smaller.

vipershark11

iTrader: (6)

how much hp you guys think ill lose from a 2.5" exhuast over a 3"?

vipershark11

iTrader: (6)

ive got all my parts in the mail including ford #30 injectors. tomorrow ill probably rip my plenum and runners off so i can pull the motor later in the week if not weekend. then on tuesday when i get the runners ill get to porting and maybe take some pictures of that and the matched plenum port. ill report back with progress guys

vipershark11

iTrader: (6)

seeing as how i got a non roller 350 block. how would this cam work with the above setup? http://store.summitracing.com/partde...4&autoview=sku will it be easy/decent to tune?