Dean-B4C6SPD

Would longtubes (preferably Hooker SuperComp) be a bad idea on my currently bone stock 305 TPI (with 6speed nonetheless) ?

Without getting too much into backpressure discussions, I'm told that aftermarket intakes would be useless for my 305TPI, so...perhaps longtubes would be useless on a stock 305TPI also ?? If not, what RWHP gains should I expect ?

Thanks for any feedback!
Dean
92 B4C 6SPD

CheezX

nah, longtubes would be great. I used the 1-5/8" Hedman's though. The Hooker's are 1-3/4" though so maybe they're better suited to a 350 or larger.

The longtubes are great, they increase power at all RPMs. No low-end torque loss at all. I just took mine for a drive with open headers. I could snap my head back by tapping the throttle. In 4th gear at 1500 rpm! It was uphill too! And mine's pretty stock, just exhaust and ignition stuff.

MdFormula350

sounds like they work great!

1MeanZ

iTrader: (9)

well anyone who told you that long tube headers or aftermarket intake parts wont work on a 305 is full of it. a 305 is a V8 engine just like anything else, about anything that will bolt to a 350 and make power, will do the same for a 305. there are quite a few guys on here runnin pretty quick with 305s and i am sure they will tell you that aftermarket intake runners, base, longtube headers, all that stuff will work. so i say start boltin stuff on and make more power, good luck.

Shagwell

I agree. Good exhaust and good intake flow will help any motor. A 305 can be very fast if built up right. I'd deffinitely stick w/ 1 5/8 headers. - As for the intake, runners and all the trick stuff will help. I just don't think you would a see a benefit from an HSR or something like that.

later, justin...

1982chevycamaroz28

yea 305's can be very fast, theres a guy on this board that runs 11.7 on a 150 shot of nitrous on his 305. i have a video recording i took of him runnin a 11.8 and i didnt even know it was a 305 until he joined the board. also he has a carberator on his motor.

but for this with 305 or any 305. bolt ons will give u power weather its an intake swap or cam. almost anything better then stock will give u performance.

right now im pushin estimated 210hp hopefully after march or so ill be pushin 300+hp with cam swap, port and polish heads, hooker supercomp long tubes, torque convevter, and get my rear straightened around. im just hopeing for 13's

Mark A Shields

I think long tubes on his motor may not help, it may not hurt him, but it will probably not help at all. Though they will be there for later on, shorty headers can support impresive hp numbers, though I just went with long tubes 1 5/8th because they were cheap , it's up to you.


I could be wrong though....

Mark A Shields

no one said they wouldn't work, just useless.

five7kid

iTrader: (14)

I would be more impressed with this testimonial if the comparision was back-to-back with shorties. Open long-tubes aren't very practical for the street (ok, not saying that's what you're advocating), and with TPI applications, you need to accomodate the O2 sensor in some manner. Long tubes also require compromises with ground clearance, and if you're in an emissions-inspection area, may not be an option in any case. They can also be more expensive by the time you get everything routed where it needs to go (read: custom exhaust).

More than likely, a good set of shorties with a free-flowing y-pipe and cat-on-back will serve as well as any long tubes ever could on a daily driver.

CamaroDriver

IMO..... it would help. All headers do.

It wouldn't make much sense though. Long tubes are primarily used to increase low RPM grunt, which the 305 has very little of in the first place. It's like trying to make a mouse (pun intended ) stronger by giving him steriods.... he'll be a strong mouse, but still a mouse.

CHP tried that same avenue on that "budget" build up they did with the '87 Camaro. They tried using a smaller cam on the 305 to "boost low RPM torque". Boy did they TOTALLY miss the head of the nail on that one, and smashed their thumbs in the process. :sillylol:

If you're going to build an engine, find out what that engine's good for, and build around that. You'll be much better off.

Mark A Shields

I thought TPIs were all about low rpm tq (grunt)

1MeanZ

iTrader: (9)

some of you may have heard of Ray T Boahcz, he has written many artilces for GM high tech performance on tpi. i believe he says in one of his articles that tpi engines make torque due to their long runner intake. the intake is what causes the engine to make the torque it does. that is why SLP recommends huge 1 3/4 primary headers for stock 350 motors. on a tpi motor i think you can put anyting on it and it will still make about the same torque. now in a carburated application, i dont think the same holds true. i will have to dig out my back issues and look for his article but i am pretty sure that was his take on it.

CamaroDriver

They are..... but putting them on a 305 IMO, is just as silly. But I didn't do that, GM did. It was a sad attempt to do what I said CHP tried

TA5LiterHO

To be honest with you. Having worked in an engine shop for 8 years doing top and bottom ends, I have seen what makes the 305 tick. My first sugestion, if you want a fast 305 is to get rid of the TPI. I have seen some great TPI's. But those engines were 350's. The TPI stock system hit peak power at about 4800 rpm. I have yet to this day see a 305 tpi run "exceptably." My suggestion, depending on the emissions standards of wherever you are from would be to do what I have done on my 84 Trans Am. I built a new 305 out of a 1992 block which was previously a tpi. Put a nice intake on it and carb it. Now if you are looking for an easy starting technologically advanced car this is not for you. But anyway, Intake and carb and cam. Unfortunately the highest you would want to go safely on lift in a gm 305 is like 460 lift. I have found that 440 is a good lift for these engines. Roller rockers are not really a necessity, but they will work if you want em. Just make sure you use stock rocker ratios or you will raise the lift too much. Put some underdrive pulleys on, get a vacuum advance distributor and a nice torque converter. If you do these things you will get a nice amount of reliable power out of your gm 305. Trust me. Mine dynoed at about 320hp and it runs in the 13's. Don't get me wrong, I like the tpi system, but sometimes it is more trouble than its worth, especially when modding the motor.

TA5LiterHO

Oh yeah forgot to mention. I am running 1 5/8 inch headman shorties, the ypipe that goes with it a high flow cat and a flowmaster 80 series muffler.