Irocdriver89

what's the horsepower on this car from stock, not to the fly but to the rear wheels is what i want to know. and also i have duel cats on this car and i'm adding headers this weekend can i run two real pipes since i have two cats on the car anyway and would it be stupied loud like all the ricers on my block(j/k) oh the g92 option is cool there were so many performance up grades my favorite would be the drive shaft they used.

camarokid04

well its about 250 at the fly and i think the transfer power diff. is about 18-22% so we'll go with 20 to be safe and say it has about.... 250-49(for power loss) = around 200 hp and then u figure in miles and stuff so your prob. pretty close to 200 hp stock...

now for the question about your headers... if i were you and many people will probably agree, unless you are gonna run true duals and do it yourself the best route is to probably buy the headers, 3" y-pipe, 3" cat and a 3" catback exhaust, a single 3" will support like 350+ at the wheels so unless u plan on going heads, cam, intake etc... then you should be fine with that. but like i said if you have the money to run true duals go for it, if it where me in your situation, i would plan on modding more later so i would go headers and true 3" duals that dump right before the rear end... but thats just me

hope this helps

87DJP2001

No more then 200 RWHP or maybe less.

Irocdriver89

thanks for the horsepower quote i think i will go true duels because most owners do not do this and it has to offer more horsepower than running into one pipe thats just more air flow than stock.i also have slp ram air hood, i'm going with 2 chamber flows, hypertech chip,and headers so i would say about 280 horsepower to the fly now ADLEASE it feels that way with the posi unit that i have.

camarokid04

sounds great. however if i were you i would not waste the money on the hypertech chip, do some research here and on www.thirdgen.org for more info on chips. people have actually ran slower after installing that chip, just a little fyi. you can get into chip tuning yourself and it will see much more power that route. and do you know how you want to route your duals? and i love the way 2 chamber flowmasters sound they have been on my last 2 thirdgens, 89 IROC with a 350 TPI, same are yours, and now my 92 RS. good luck and if your not already on tgo i would recommend it i have been a member here and there for nearly 3+ years and both are great!!!

1fastformula

89 350 TPI w/dual cats= 225 hp flywheel (Z28 had 235 hp)

Convert the 20% drive loss and it roughly comes out to 188-189 rear wheel. In good tune you can get close to that....Bad tune...Not as good.

Later

1fastformula

Take magazine est. HP increase and cut the m in half!!!! Jsut a rule you need to live by

Stock 235hp
Headers +10
Chip (fastchip from Ed Wright) +6
2 chamber flows +10
Duals +7

Total estimate.......... 268 Hp

Let me know what happens when you dyno the setup....Make sure you are not pinging also (too much timing) THIS WILL HURT YOUR HP NUMBERS!!!!!

Later

camarokid04

where are you getting those numbers? if you look on TGO both the IROC and the GTA with the G92 came with the optional 3.27 posi and 240 flywheel hp and 345 flywheel tq. if you are getting the numbers from somewhere else please show me the site....

and typically the birds had more hp because the intake design was less restrictive from the factory...

and on the power numbers i have seen headers with a 3" y-pipe and cutout good for as i recall 28 hp at the wheel and over 35 tq on an L98, so you figure 195(being safe) at the wheels, + 28 for the exhaust, and then a chip is probably close to 230 at the wheels... there is really only one true way to see, dyno before mods and dyno afterwards, all cars wont respond the same.

87DJP2001

Another Post on how to make Horsepower by addition. Everything works together and not by adding them up.

1fastformula

My mistake on the numbers........ Good catch.

The adding of HP numbers was just an estimate...Dyno has to be done to back up anything.

I see you dynoed your 350 crate......... Was that the vortec headed version or the GM goodwrench version?? The numbers just seem a little low to me.

Later

1fastformula

I was just trying to help the man...he had 280 HP at the flywheel with his add up....Going to the dyno thinking that and then getting something lower SUCKS!!!!! Just trying to brace him for any disappointment that may arise.

get out of here with that........Why must people add insult to any correction they point out???

I was just trying to help out



Later

aklim

I disconnected my exhaust at the collectors and haven't made any significant power with respect to with it on a 3 in. I'll bet if you really do it right on a dyno you won't notice anything significant between true duals and not. Just because few people do it or everyone does it doesn't mean it will work or won't. Even if it flows like a sewer pipe, your restriction will the the rest of the system. Just because it flows more doesn't mean you will be able to use it.

Marc 85Z28

You got that backwards bud. The Camaros came with the less restrictive dual snorkel air cleaner. The Firebirds lower hoodline eliminated the room necessary to fit the dual snorkel, and thus were equipped with the single, more restrictive intake. A good rule of thumb is about 5hp LESS than a similarly equipped Camaro.

The GTA Source Page has all the info you need.

1fastformula

What.....no with the correction??!!!??!?!

Good to see there are still a few good people out there.

Thanks for backing up what I had to say with the webpage!!

Later

Irocdriver89

well i went to the dyno yesterday and it showed 273 horsepower to the fly with 360 torque which was pretty good for my setup the guy said. i added the air foil,hooker headers,borla catback ,true duel piping,1.6 roller rockers,bbk throttkle ram air hood with ram air setup, i did cheat a little i ran a fan in front of my car to cool the air oh thanks for the suggestion i did not buy the hypertech chip i had one burned by a guy who worked at a speed shop.