Adding power to my 305?
Thread Starter
Member
Joined: Oct 2009
Posts: 194
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From: Willows, CA
Car: 1987 Firebird Trans Am
Engine: 305 TPI (68,XXX MILES!)
Transmission: 700R4
Axle/Gears: 2.73
Adding power to my 305?
I'm looking to get some more power out of my 305 TPI, my goal is up around 250 horsepower.
Since the car is my daily driver.. I'm not planning on doing anything drastic, I'm thinking more along the lines of bolt ons and such.
I plan to buy some hooker headers (which ones do you guys reccomend?), the American Thunder Catback from Flowmaster, some high flow runners, and well.. I'm not to sure what else.
What do you guys think I should look into? Could you guys offer some links on what I should look into to get up around my goal? Having 250 HP sounds helluva lot better than having 190. Haha.
Thanks in advance guys.
Since the car is my daily driver.. I'm not planning on doing anything drastic, I'm thinking more along the lines of bolt ons and such.
I plan to buy some hooker headers (which ones do you guys reccomend?), the American Thunder Catback from Flowmaster, some high flow runners, and well.. I'm not to sure what else.
What do you guys think I should look into? Could you guys offer some links on what I should look into to get up around my goal? Having 250 HP sounds helluva lot better than having 190. Haha.
Thanks in advance guys.
Junior Member
Joined: Aug 2008
Posts: 18
Likes: 0
From: Reynoldsburg,OH
Car: 1987 Z28 Camaro
Engine: 305 TPI 5.0
Transmission: 700r4
Re: Adding power to my 305?
i would also like to know i have a 305tpi in my 87 camaro some links would be nice i know around what i would like to spend but if its to much of a hassel i could just 350 the car
Junior Member
Joined: May 2009
Posts: 92
Likes: 0
Car: 92 Camaro RS
Engine: 305 TBI
Transmission: 700R4
Axle/Gears: Open 2.73
Re: Adding power to my 305?
Well the trick is to open the engine up and let it breath.
I bought hedman headers and y-pipe for mine and they work great. The headers were #68470 and the y-pipe was #17470 and I bought em at Jegs. Well I took the smog pump off mine, but if you still have yours then go onto the jegs website and look around for some emissions type headers.
Then the catback like you were sayin and some better runners. After that I would look into an underdrive pulley. A guy on ebay sells a set of hawks racing ones that are cheap but still good quality.
Then a peformance chip would be a plus to help the engine better cope with opening it up. You can either buy one, Ive got a hypertech, or you can burn your own, if you wanna take the time to learn.
After that go get yourself a set of i think its 1.6 roller rocker tips.
Oh yeah, a cold air intake or something that opens the intake up will help too.
That should get you up there, I dont know if its quite 250 but it will be close, if i think of anything else ill let you know.
I bought hedman headers and y-pipe for mine and they work great. The headers were #68470 and the y-pipe was #17470 and I bought em at Jegs. Well I took the smog pump off mine, but if you still have yours then go onto the jegs website and look around for some emissions type headers.
Then the catback like you were sayin and some better runners. After that I would look into an underdrive pulley. A guy on ebay sells a set of hawks racing ones that are cheap but still good quality.
Then a peformance chip would be a plus to help the engine better cope with opening it up. You can either buy one, Ive got a hypertech, or you can burn your own, if you wanna take the time to learn.
After that go get yourself a set of i think its 1.6 roller rocker tips.
Oh yeah, a cold air intake or something that opens the intake up will help too.
That should get you up there, I dont know if its quite 250 but it will be close, if i think of anything else ill let you know.
Junior Member
Joined: May 2009
Posts: 92
Likes: 0
Car: 92 Camaro RS
Engine: 305 TBI
Transmission: 700R4
Axle/Gears: Open 2.73
Re: Adding power to my 305?
Well your lookin at about $600 -$800, maybe less depending on if you can get the parts a little cheaper, to put everything I said in your car. The best thing is though, is that most of that will transfer over if you do decide to switch to a 350.
The cheapest and most gain dollar for dollar though would be to get a 350.
Junior Member
Joined: Aug 2008
Posts: 18
Likes: 0
From: Reynoldsburg,OH
Car: 1987 Z28 Camaro
Engine: 305 TPI 5.0
Transmission: 700r4
Re: Adding power to my 305?
Well if your lookin for some bolt ons for now to add a little power I wouldnt suggest throwin a bigger engine in, but if you wanna go past that 250 zone, buying a 350 would work out better.
Well your lookin at about $600 -$800, maybe less depending on if you can get the parts a little cheaper, to put everything I said in your car. The best thing is though, is that most of that will transfer over if you do decide to switch to a 350.
The cheapest and most gain dollar for dollar though would be to get a 350.
Well your lookin at about $600 -$800, maybe less depending on if you can get the parts a little cheaper, to put everything I said in your car. The best thing is though, is that most of that will transfer over if you do decide to switch to a 350.
The cheapest and most gain dollar for dollar though would be to get a 350.
Senior Member

Joined: May 2002
Posts: 845
Likes: 0
From: Northern California, Redding
Car: Red 1987 IROC Convertible
Engine: 305 LB9 TPI
Transmission: T5 5-Speed
Axle/Gears: 9-Bolt 3.45
Re: Adding power to my 305?
You need to change the cam and exhaust to get to 250 HP.
Joined: Feb 2003
Posts: 2,498
Likes: 20
From: PNW
Car: 91 Black Formula KR
Engine: 305 TPI R69/G92
Transmission: Astro A5-Pro 5.0-McCleod
Axle/Gears: US Gear 3.42 Eaton True Trac
Re: Adding power to my 305?
Agreed... Cam and Exhaust... my 91 Formula 5.0 TPI 5 speed was close to that stock, because of the better cam and G92 dual cats...
With Hooker 2055 Headers & Y pipe, High Flow Cat, 3" catback, I'm sure it's at 250 or more... a chip and open up breathing (cold air) would also help...
With Hooker 2055 Headers & Y pipe, High Flow Cat, 3" catback, I'm sure it's at 250 or more... a chip and open up breathing (cold air) would also help...
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Thread Starter
Member
Joined: Oct 2009
Posts: 194
Likes: 0
From: Willows, CA
Car: 1987 Firebird Trans Am
Engine: 305 TPI (68,XXX MILES!)
Transmission: 700R4
Axle/Gears: 2.73
Re: Adding power to my 305?
Where could I get a cold air intake? I haven't seen any. And are installing the runners an easy thing to do?
Supreme Member
iTrader: (9)
Joined: Mar 2007
Posts: 1,804
Likes: 2
From: Raleigh, NC
Car: 1988 Flame Red Trans am GTA
Engine: Forged 355 4 Bolt, FIRST TPI
Transmission: 700r4
Axle/Gears: ls1 torsen 3.42 gear
Re: Adding power to my 305?
for a 305 and stock heads.. get the powermax 2032 cam.. one of the biggest cams you can get for your stock heads... its 214/220 452/465 on 112lsa.... sounded nice in my old l98 should sound lumpy in a 305...... noticed a buttload of torque off the line.. get the cam freshen up the heads with springs/retainers/guides/seals along with headers and exhaust and you should have your 250hp..
Senior Member
Joined: Dec 2009
Posts: 517
Likes: 1
From: Toronto
Car: '88 Trans Am GTA
Engine: 305 TPI
Transmission: 700R4
Re: Adding power to my 305?
Putting your car on the bottle is by far the quickest and easyest way to get to your 250hp goal. Not very practical tho.
Supreme Member
iTrader: (9)
Joined: Mar 2007
Posts: 1,804
Likes: 2
From: Raleigh, NC
Car: 1988 Flame Red Trans am GTA
Engine: Forged 355 4 Bolt, FIRST TPI
Transmission: 700r4
Axle/Gears: ls1 torsen 3.42 gear
Re: Adding power to my 305?
i wouldnt nos any engine that old... too many problems can occur with an engine with that many miles... plus its only there when your using it.... to me nos is cheesy and kiddish to me..... most of my friends blew their engines using that stuff.... and im 21....
Senior Member

Joined: May 2006
Posts: 627
Likes: 1
From: Glendale, CA
Car: 1992 RS
Engine: LS1
Transmission: T-56
Axle/Gears: 3.42
Re: Adding power to my 305?
On my 305 that has 182,xxx miles I have SLP runners, Edelbrock baseplate, SLP 1 5/8 shorites with a Dyno Don y-pipe, car has been converted to duel cats, Magnaflow 3 inch catback. Got the car dynoed a couple weeks ago and I put down 198hp and 266tq to the wheels with the stock tune. I believe thats close to 250 hp and 330tq at the flywheel. I run 9.5's in the 1/8 mile with 2.77 gears and the car is smog legal. Hope this helps!
Senior Member

Joined: May 2002
Posts: 845
Likes: 0
From: Northern California, Redding
Car: Red 1987 IROC Convertible
Engine: 305 LB9 TPI
Transmission: T5 5-Speed
Axle/Gears: 9-Bolt 3.45
Thread Starter
Member
Joined: Oct 2009
Posts: 194
Likes: 0
From: Willows, CA
Car: 1987 Firebird Trans Am
Engine: 305 TPI (68,XXX MILES!)
Transmission: 700R4
Axle/Gears: 2.73
Senior Member

Joined: May 2006
Posts: 627
Likes: 1
From: Glendale, CA
Car: 1992 RS
Engine: LS1
Transmission: T-56
Axle/Gears: 3.42
Re: Adding power to my 305?
Senior Member
Joined: Dec 2009
Posts: 517
Likes: 1
From: Toronto
Car: '88 Trans Am GTA
Engine: 305 TPI
Transmission: 700R4
Re: Adding power to my 305?

To answer some of ThirdGenFire93's questions. I'd recomend Edelbrock CES headers and y pipe. They're 50 stae smog leagle, flow well, and are a decent price. Stay away from the SLP CAI, all they are is a 200+ dollar air box. Your best bet is to get a 3" 45 degry and 90 degry peice of polished aluminum intake tubing and trim it to fit (if you go with Vibrint performance tubing there will be more than enough) with a high flow cone filter with 3" outlet. Up here each pipe is $25CND plus the cost of the filter. Make sure if you go this route you trim the radiator overflow outlet because, speeking from experiance, it will cut the overflow hose and dump coolant at operating temp. Flowmaster sounds good but I suggest a Magnaflow cat back because it flows much better. Also get a throttle body air foil. tou shouldn't need a lager throttle body with only 250hp.
Thread Starter
Member
Joined: Oct 2009
Posts: 194
Likes: 0
From: Willows, CA
Car: 1987 Firebird Trans Am
Engine: 305 TPI (68,XXX MILES!)
Transmission: 700R4
Axle/Gears: 2.73
Member

Joined: Nov 2001
Posts: 245
Likes: 1
From: somewhere over the pond
Car: '91 Z28
Engine: LB9
Transmission: T5
Axle/Gears: 3.42
Re: Adding power to my 305?
CAI, catback, cam and headers should you get there.
Dont know if there are some decent heads beside the vette-heads
my mods:
Borla catback
custom cold air with airfoil
adj. fuel pressure regulator
Dyno: 251hp (204 rwhp)
Now added hedmann shorties and thinking about SLP runners and a custom tune.
Dont know if there are some decent heads beside the vette-heads
my mods:
Borla catback
custom cold air with airfoil
adj. fuel pressure regulator
Dyno: 251hp (204 rwhp)
Now added hedmann shorties and thinking about SLP runners and a custom tune.
Supreme Member
Joined: Jan 2009
Posts: 1,126
Likes: 0
From: Columbus Ohio
Car: 91 Z28,64ImpalaSS4094spd,67 Galaxy
Engine: Dart 415Profiler hd,cmprlrs,Hlly750
Transmission: Built 700R4, 3200 stall
Axle/Gears: 3:89 Moser 9"
Re: Adding power to my 305?
When I had my 305, I put a cam, headers and flowmaster catback, K&N filters, removed airbox baffles, and drilled out airbox. I also put an MSD probillet dist. The dist really helped smoothout power throughout the entire rpm range. Another helpful cheap mod was removing the screen on the MAF sensor, and coolant bypass on the tpi.... All of these really helped the car make more power and breathe better...
Senior Member
Joined: Dec 2009
Posts: 517
Likes: 1
From: Toronto
Car: '88 Trans Am GTA
Engine: 305 TPI
Transmission: 700R4
Re: Adding power to my 305?
http://www.hawksthirdgenparts.com/ed...dersystem.aspx I couldn't find them on Edelbrock's site tho. So it might be discontinued.
Senior Member

Joined: May 2006
Posts: 627
Likes: 1
From: Glendale, CA
Car: 1992 RS
Engine: LS1
Transmission: T-56
Axle/Gears: 3.42
Re: Adding power to my 305?
Headers
http://www.top-downsolutions.com/pro...818c8a1b5aabbd
Y-pipe
http://www.top-downsolutions.com/pro...aeddee16661d1f
A thread about the quality and some pics
https://www.thirdgen.org/forums/exha...s-exhaust.html
http://www.top-downsolutions.com/pro...818c8a1b5aabbd
Y-pipe
http://www.top-downsolutions.com/pro...aeddee16661d1f
A thread about the quality and some pics
https://www.thirdgen.org/forums/exha...s-exhaust.html
Supreme Member
iTrader: (1)
Joined: Jun 2009
Posts: 1,777
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From: Central Connecticut
Car: 91 Trans Am 'vert
Engine: LB9
Transmission: T5
Axle/Gears: 3.45 9 bolt
Re: Adding power to my 305?
subscribing to this. I have a stock 305 TPI that I'd like to squeeze a little more out of as well. Good luck with yours!
Thread Starter
Member
Joined: Oct 2009
Posts: 194
Likes: 0
From: Willows, CA
Car: 1987 Firebird Trans Am
Engine: 305 TPI (68,XXX MILES!)
Transmission: 700R4
Axle/Gears: 2.73
Re: Adding power to my 305?
Thanks alot for subbing. My car is up and running again as of today, new radiator 
In three or four weeks my car shud be painted, looking new, then I can start with the performance upgrades. Atm im looking into a good set of hooker headers, and a possible cat-back. But I've heard that upgrading to three inch pipe isnt worth it?

In three or four weeks my car shud be painted, looking new, then I can start with the performance upgrades. Atm im looking into a good set of hooker headers, and a possible cat-back. But I've heard that upgrading to three inch pipe isnt worth it?
Supreme Member
iTrader: (1)
Joined: Jun 2009
Posts: 1,777
Likes: 0
From: Central Connecticut
Car: 91 Trans Am 'vert
Engine: LB9
Transmission: T5
Axle/Gears: 3.45 9 bolt
Re: Adding power to my 305?
Thanks alot for subbing. My car is up and running again as of today, new radiator 
In three or four weeks my car shud be painted, looking new, then I can start with the performance upgrades. Atm im looking into a good set of hooker headers, and a possible cat-back. But I've heard that upgrading to three inch pipe isnt worth it?

In three or four weeks my car shud be painted, looking new, then I can start with the performance upgrades. Atm im looking into a good set of hooker headers, and a possible cat-back. But I've heard that upgrading to three inch pipe isnt worth it?
Thread Starter
Member
Joined: Oct 2009
Posts: 194
Likes: 0
From: Willows, CA
Car: 1987 Firebird Trans Am
Engine: 305 TPI (68,XXX MILES!)
Transmission: 700R4
Axle/Gears: 2.73
Junior Member
Joined: Jan 2010
Posts: 23
Likes: 0
From: massena ny
Car: 1991 trans am
Engine: LB9 tpi
Axle/Gears: 2.73
Re: Adding power to my 305?
most people that are dumb and watch that fast and fuggin furious take a motor that makes 200hp and his it with a double shot of 300 and brag they got 500 horse then the first time they spray it they melt down, nitrous isnt kiddish its just another performance part that takes understanding to use, if nitrous is cheesy so then are turbos and blowers, not trying to **** any body off just my opinion
Member
Joined: Nov 2009
Posts: 197
Likes: 0
From: Goshen, KY
Car: 1991 Camaro RS, 2013 Camaro SS 1LE
Engine: LT1
Transmission: T5
Axle/Gears: Stock
Re: Adding power to my 305?
Thanks alot for subbing. My car is up and running again as of today, new radiator 
In three or four weeks my car shud be painted, looking new, then I can start with the performance upgrades. Atm im looking into a good set of hooker headers, and a possible cat-back. But I've heard that upgrading to three inch pipe isnt worth it?

In three or four weeks my car shud be painted, looking new, then I can start with the performance upgrades. Atm im looking into a good set of hooker headers, and a possible cat-back. But I've heard that upgrading to three inch pipe isnt worth it?
in my opinion it is better better flow less restriction and will sound a lot better than the factory exhaust... I am on the same quest as you this week i just put in a new fuel pump, new injectors (19lbs ford racing), adjustable fuel pressure regulator from BBK (feels like it made a pretty good increase in power as well torque) I just purchased a Magnaflow 3in cat back exhaust off of summit as well the Magnaflow cat to compliment the exhaust system and the headers I am getting next week which are the Edelbrock 68722 off of Summit. I would suggest doing mods like these to get a tad bit more outta the car itself and the next mod for me is a LT1 cam and vortec heads.
Member

Joined: Nov 2001
Posts: 245
Likes: 1
From: somewhere over the pond
Car: '91 Z28
Engine: LB9
Transmission: T5
Axle/Gears: 3.42
Member
Joined: Nov 2009
Posts: 197
Likes: 0
From: Goshen, KY
Car: 1991 Camaro RS, 2013 Camaro SS 1LE
Engine: LT1
Transmission: T5
Axle/Gears: Stock
Thread Starter
Member
Joined: Oct 2009
Posts: 194
Likes: 0
From: Willows, CA
Car: 1987 Firebird Trans Am
Engine: 305 TPI (68,XXX MILES!)
Transmission: 700R4
Axle/Gears: 2.73
Re: Adding power to my 305?
http://www.autoanything.com/exhausts-mufflers/61A3993A0A0A3099723.aspx
And it asks me if I have the code H engine or the code F engine, Im assuming one is for TPI and one is for TBI. Which code specifies TPI?
Last edited by ThirdGenFire93; Feb 12, 2010 at 02:43 PM. Reason: Errors.
Supreme Member
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Posts: 1,468
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From: Minnesota
Car: 89 IROC-Z
Engine: 370 LSX, LS3 Top End
Transmission: Built T-56
Axle/Gears: 9" Aluminum Center 3.89's
Re: Adding power to my 305?
n2o will be the cheapest. all the ****in myths out there came from those damn movies. Run a cheap single nozzle setup, pull timing and run a colder plug.
Member
Joined: Mar 2009
Posts: 219
Likes: 0
From: Warrior AL
Car: 89 Iroc
Engine: 350/Dart heads/hotcam/TPI
Transmission: T56
Axle/Gears: 3.45 9bolt
Re: Adding power to my 305?
What you are looking for is basically what I put together. I made 226 rwhp and 290 rwtq. On a manual transmission thats about 260 flywheel Hp and about 330 ftlbs of torque. I have a ported/seimesed plenum and base and ported and patially seimesed SLP runners, descreened maf, gutted airbox, Edelbrock headers, flomaster Y pipe, pully kit, Loud mouth Cat back, three inch from the Y pipe to the muffler, 1.6 roller tip rockers, apr, custom chip tune, and right at 300,000 miles on the engine/car. I am running a T56 trans. To get the power you want I really believe that what I have done is about as far as you can go with out changing the cam or the heads. ONe day I may do a 350 but I am satisfied with the way it drives for now. It finally makes enough power to keep up with at least some of the new cars.
I have gone from being down on the 305 to being very happy with it. I plan to take it to the track again this spring. No predictions but I am hoping for the high 13's. I do believe it can be done.
I have gone from being down on the 305 to being very happy with it. I plan to take it to the track again this spring. No predictions but I am hoping for the high 13's. I do believe it can be done.
Joined: Dec 1999
Posts: 1,747
Likes: 26
From: Rugby, England
Car: 1988 IROC Vert
Engine: 355 ZZ4
Transmission: T5 Manual
Re: Adding power to my 305?
I know this is an old thread but I think it's a good one.
The best seat of the pants upgrade is rear gears. I have gone from 2.77 to 3.73 and Jeez it flies!
Is the powermax cam still considered the one to go for? Is it computer friendly? Just seems so expensive still, would love to do the cam at some point.
The best seat of the pants upgrade is rear gears. I have gone from 2.77 to 3.73 and Jeez it flies!
Is the powermax cam still considered the one to go for? Is it computer friendly? Just seems so expensive still, would love to do the cam at some point.
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iTrader: (1)
Joined: Jul 2000
Posts: 1,290
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From: Carson, CA
Car: '88 GTA, 90 Formula
Engine: 5.7 TPI, fed growth hormones
Transmission: 700r4 4u2?
Axle/Gears: 9bolt
Re: Adding power to my 305?
Also, I would not recommend the Edel-broke headers. Having had a set, they are also a poor design and I believe they are no longer in production anyway. Hooker 2055s are fine for a 305 on a budget, but Dyno Dons are the best.
TA
Last edited by TA; Nov 8, 2012 at 01:11 PM.
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