i have a flow masters dual exhaust (y pipe) and i was wondering would headers be worth the moiney in this car? cause i am sick of getting beat by new v6 mustangs when my car is a v8..... or should i honestly swap my pipes out and get like a X pipe cause i heard these pipes are the way to go andy suggestions write back that'd be awsome

 

damn man v6 stang are beating you i have a 91 with a 305 tbi and i ate up a 3.8L firebird i drew up an image of what im doing i dont have an X pipe but im making my own so heres the pic if you want to check it out its also gonna be catless.

http://img444.imageshack.us/my.php?i...orplansqn5.png

 

The 305TBIs are dogs.........
And if you beat a 3.8, it must have been in poor shape [they run high 14s I think]

A full exhaust will give you very little power, maybe 15hp if youre lucky.
Exhaust helps, but just adding exhaust to a 305TBI sadly wont be enough to beat the 3.8 Mustangs and definitely not the newer 4.0.

I had full exhaust on my low mile 305TBI [around 40k miles at the time], fresh tune up and it made like 146whp I think, pretty pathetic for a V8. 146 was after tuning too, on the first pull it was like 134whp or something.

 

my 305 is upgraded man too much too list but he had an exhaust on his that all i know and he picked his gf up from school then he reved his engine behind me out of school then we came to a light and he nodded his head i was like ok then and i dusted it. i embarassed him and his gf that goes to my school ever since that he never did that crap again
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btw Timothayyy the 305 tbi came with 170 stock so something must have been wrong with yours 146 thats lower than a vtec civic vtec civics have 160 hp stock.

 

91 RS
Firebird M5,A4 LH0 V6 8.5:1 3.1 (191) 140@4400 185@3600 MFI 3.42 ---- 3.23 ---- 91 RS
Firebird
Formula M5,A4 LO3 V8 9.3:1 5.0 (305) 170@4000 255@2400 TBI 3.08 ---- 2.73 ---- 91 Z28
Formula
Trans Am
GTA M5,A4 LB9 V8 9.3:1 5.0 (305) 205@4200 285@3200 TPI 3.08 ---- 2.73 ---- 91 Z28
Formula
Trans Am
GTA M5 LB9 V8 9.3:1 5.0 (305) 230@4200 300@3200 TPI ---- 3.42 ---- ---- 91 Z28
Formula
Trans Am
GTA A4 L98 V8 9.7:1 5.7 (350) 245@4400 345@3200 TPI ---- ---- ---- 3.23

 

I said Wheel horsepower. As in going to the wheels. The factory numbers are from the crank, with no engine accessories.

Go spend the 75$ or whatever for 3 baseline pulls, I bet you wont have anywhere near the power you think you have, if you used the factory rating of 170 as your mental baseline.

 

I have a 305 HO that makes 386 HP @ 6950 rpm the secret is the superstock recipe by david nickens a current pro-stock engine builder

 

Must be a built motor.
I was talking about having 146whp on a stock motor with just shorty headers and exhaust.

 

you have to think its old and warn down though so through time your performance and hp will decrease
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so any suggestions for good hp and more torque

 

As I said, it has low mileage and was well maintained.
They NEVER made 170hp to the wheels. Even new cars like the Mustang GT claims 300hp, but on the dyno they only make around 260 I think [maybe 280]. Its because the rated horsepower is from the crank and not whats going to the wheels.

 

What if it was carb instead of TBI?

 

Something must have been wrong with your 305, i have no problem dusting 3.8's in my 305. Even easier from a dead stop.

 

Back to your original question about headers and y-pipe. I am currently doing research on headers and a y-pipe. I am on a tight budget, so I am looking at the Summit budget headers (Sum-69005) with 2.5" collectors bolted to a Hedman y-pipe (Hed-17470). Together, they are only $200. I then plan on deleting the cat and running a 3" exhaust pipe to my Flowmaster muffler. However, one salesman at Summit racing said the shorty headers and hedman y-pipe would work together, and one saleman said it would not: so I don't know what to do now.

Based on other things I have read, the 2.5" exhaust is not restrictive until you reach 250 h.p. The stock 2.25" pipes become restrictive at 175 h.p. Additionally, I read there may be clearance problems around the oil pan with a 3" y-pipe.

Just google "305 build up Car Craft" and there is a great build-up of a 305 LO3. Based on Car Crafts results, there is more than 15 h.p. to be gained from better headers and a y-pipe.

 

Take a look at hooker 2055's probably the best bang for the buck. nice y pipe too.

 

Not true. The factory rating is at the crank, true, but with the intake and exhaust system as installed in the car, running the alternator and water pump providing required electrical power to the engine (ECM, fuel pump, etc.).

I'd recommend the Hooker 2055HKR as well. Best off-the-shelf deal available for single cat.

 

would the Hooker 2055HKR work with a carbureted 305 berlinetta? without the catalytic converter?

 

As far as factory HP ratings. Don't most car companies underrate for insurance purposes? Or was this something done only in the 70's?

 

No,and they would not on already under powered cars. Also why revive the 4 year old thread?

 

About 13 years ago my 91 RS 305 TBI A4 with about 225,000 miles on it dyno'd 135ish rwhp and 220rwtq. Car was in excellent condition getting 30+ mpg. Friend had a 305 TBi M5 with SLP headers that dyno'd 150rwhp. My convertible 305 TBI A4 with 114000 miles dyno'd 125rwhp 215rwtq. This pretty typical for the 170 flywheel rated 305 TBI.