Im planning on doing some mods to my engine in the next few months, and im just wondering what type of quarter times i might be able to expect. first of all, this will be on a 355, with 700r4 and 3.73's.
That said, i bought a tpi setup, and im done porting the plenum, and im siamesing the base, and ive got 24lb/hr injectors. im putting this on some pretty good heads (not positive yet), probably World or dart. im going to get a powermax cam (272/284) with .454/.480 lift, and roller rockers. on the exhaust im going with edelbrock headers and y-pipe, and a single 3" muffler, either dynomax or flowtech.

thanx for ne feedback. just some ruff estimates is all im asking.

 

Hey,


On the exhaust I would not recommend either. Flowmaster's single outlet is proven to be less restrictive! Also I do not remember but are your heads cast or alum, and what size valves and comp do you think you have?

 

I wouldn't get the Flowmaster w/ single 3" outlet either. I gained 25 HP using a cutout to bypass that crappy thing. I recommend a Hooker muffler. I have one on my LS1, it sounds GREAT and is supposed to flow VERY well. I've seen people gain only 5 HP when using a cutout vs. the Hooker muffler.

What are the cam specs at .050" lift?

 

I do have to agree that the Hooker mufflers are good, They flow like 5% less than than 2 1/2 open pipe which is very good :hail: . But to prove my point is that flowmaster does flow alot better than crossflow mufflers and resistance can vary between which series of muffler you run! But overall I would have to say that the hooker muffler probably flows as good or better than the flowmaster. Does Hooker offer a cat-back system for the third gen f-bodys?

 

ok, forget the muffler, can ne one just answer my question please. we'll just pretend its straight pipes after the headers. thanx alot in advance.

 

and by the way, the heads im getting are Dart iron eagles.

 

im thinking of maybe a hooker aerochamber muffler, or i saw a monza system for it today too. ne one know how well those perform.
and about the heads they are 215cc dart iron eagles. they will be topped with 1.6 roller rockers. so with this said, can nebody tell me what i might be able to expect with a 3.73 rearend.?

 

Your first mistake was buying a LTR set up and trying to race it. Scrap it. Sell it to someone who wants to go slow. Second, go w/ a bigger cam to match your heads. The darts are good heads, but I would recomend a port job before you put them on. The 215cc runners are going to hurt your low end performance. Your 5cc away from a 220. I would recomend a 220 for a 383 or 400, not for a 355. Unless your going solid roller and plan on spinning the motor to the moon.

 

as for the intake. what does "LTR" stand for. and allso, correct me if im wrong, but it was my understanding that with the 1.6 ratio rockers that camn would be large enough for what i want.
if ltr is somehow refering to the intake being stock, than i know i made a mistake, and ive thought of selling it and getting something that will feed the engine to a higher rpm. i love to hear the engine scream, thats why the dart heads are allso equipped with 240# springs, so if you have a suggestion for a tpi replacement intake than please feel free to point me in the right direction. i would like to be able to get it for under 400 without wiring if thats possible. im talking 7500 rpm or more.

thanx,
ian larson

 

7500rpm or more I would strongly recommend a solid roller cam. Hydrolic lifters will bleed down and result in a loose valve train and beat itself to dealth.

As for the intake, yes, the LTR stands for long tube runner which is what a TPI is. As well as the Supper Ram. Its been proven over and over again that they don't make great power. They make "good" power, and if your happy w/ that then so be it. I'm not, and a lot of others aren't.

springs - is that 240# the seat pressure or open pressure? Because if that's the open pressure those springs will never see past 6000 rpms. Well, pieces of them might. But they won't last. Look into a rev kit from AFR or into springs w/ an open pressure around 350 and up. Even 350# could experience valve float above 7000rpm. It depends a lot on how much the valve weighs.

Good luck. Power doesn't kill a bottom end, RPMs do.

 

thanx for the info freebird, and the 240# is seat pressure on those springs. and as for the bottom end, i currently have a race ground crank in the car. extra 3 thousandths clearence i believe, but if i build a new motor for this, which im starting to think i might, it will allso be race ground and have forged lunati rods. so i think ill be safe there. im looking at maybe getting a hsr, how would it do on rpm.? thanx.:hail:

 

I'm pretty bias on this. Personally think the HSR is the greatest thing that's happend in a very long time. It flows in the 270 cfm range out of the box. With a little porting it'll support flow numbers above 300cfm. That's pretty impressive for a $400 intake. I've seen dyno sheets that shows the intake making power up to 6600rpms on a HOT cam. We all know how small that is. Put a cc306 or bigger, matched w/ your DARTS and you've got a damn good motor. It'll take one hell of a motor to "over power" that intake.
It would be interesting to see what rpm the power starts to drop off w/ a ported HSR. Someone did the calculations on it to find where the theoretical peak hp would be made w/ that intake. They used the runner size and length to come up w/ it. Personally I think they were being a little conservative. Getting up around 7500 rpm and higher it might be questionable.

 

well, thanx alot for the info. im definatley going to do the hsr, and the dart heads are about a positive. probably wont get done untill thanxgiving or even christmas scince ive started school again, i only get to work 4 hours a day now instead of 10, so itll take a bit to save the money, plus i'll probably either buy a 4 bolt block, or buy the caps and machine new holes.
i have some questions about the hsr though, will my stock fuelrails, and injectors work on the hsr, or does it take specialty items.? how much will i need to take off of the stock tpi unit i have, if i just get the 299 dollar intake and plenum out of jegs? does it come TOTALLY bare?

thanx,
ian

 

I'm not possitive on this. I went through Thunder racing and got mine when it first came out. It cost almost 500 but that was w/ an AFPR, fuel rails, and fittings. Call summit and they should be able to tell you. I think its totally bare. You either have to use the fuel rail dit from holley or make your own. There's a lot of posts that go into great detail about how to do the fuel lines. Just search.

 

I was reading about your ideas and that sounds similar to what I am doing. I am running the HSR on my new 385 with AFR Hydra Rev. I am not going with huge heads or huge cam. This is my daily driver and I built the motor to be a solid blower engine. Once I get the charger it should put me where I want to go.

As for the HSR, I agree it is a very nice intake. I haven't yet gotten the engine running, but just based on how it comes from Holley, you can't find a better deal...

The one from Summit is just the intake. You should order from Thunder Racing and get the intake and fuel rail kit. The fuel rail kit is necessary unless you can fabricate your own. For the whole thing, I paid just under $500 to my door. Thats not bad when you consider I paid over $400 for just a TPI base manifold from TPIS! And the TPI won't support the airflow that the HSR will. Heres a pic of my engine on the stand.

 

Another thing, you may need a new disributor if you have the coil in cap design. The HSR requires the small diameter cap to clear the upper plenum.

 

Ya you will need the external coil distributor for the HSR. The HSR is what I am going with :hail: . But your hood is going to cause some clearance issues with the HSR!! You may be able to modify some of the support brackets under the hood to make room!

 

I think it just fits on the Camaro but I will find out for sure here in a few days!!!