We don't even know what kind of exhaust system the OP has.... my point, as you have proven, it that there are multiple muffler designs, and to go around proclaiming "Flowmaster sucks", is pointless. Figure out the specifics of the application, and the specific muffler that is being used, before parroting some hype someone read in the Internet......

 

384rwhp was made through a cut out. when the cut out is close I just run the stock exhuast. So from what I'm hearing I should get some porting done on the AFR's.

 

Or just do it right and get rid of the AFRs alltogether.

 

There is nothing wrong with his AFR heads.....let me GUESS he needs Ai heads

After seeing YOU crack so many people for REPEATING what they read. It's your turn.

There is not a damn thing wrong with 99% of Flowmaster mufflers. It's the CROSSFLOW muffler that sucks. I got a newsflash for ya ALL crossflow muffler suck as compared to a single in/out muffler.

You could take a Flowmaster catback, put a single in/out Flowmaster shootout muffler on the SAME system and make as much power as ANY baffled muffler on the market.

Most Catbacks are ALL the same with the exception of the muffler, most all are 3 inch pipe.Bent the same way, going to the same place.

Straight through muffs such as Magnaflow, Borla are much different and MUCH louder. They will outflow ANY baffled muffler with the penalty of the noise.

To answer the OP question.

Put an electric water pump on, 5-6 rwhp

Underdrive pullies,2-3 rwhp

52mm Throttlebody, 2-3 rwhp

Accel 300+Ignition(3-4 rwhp over a MSD, Verified by Ed Wright on the dyno) 5 rwhp maybe? Over stock anyway.

Roller rockers 1.6 ratio, adjusted CORRECTLY. NOT roller tips, full roller rockers.2-3 rwhp

Synthetic engine and rear end oil.2-3 rwhp

Make sure your air filter is CLEAN but dont over oil it.

Do the dyno pull with the engine cold, less than 100* engine temp.

Ice down the intake manifold.

This should crack 400 easy.

David

 

I have actually wrenched on an AFR LT1, ports are within 3ccs of the size of mine and the CAMARO they are on is slower with a stroker than my car is. Same gears, stall is just 100rpms different from the same company. I have been over the car with him trying to make it work better.
Same car had those heads on it and a cam on a stock shortblock and ran about the same as my car did cam only at which point I had 2800 stall and 3.42s.

So I did not need to personally make the mistake of buying AFR to have first hand experiance with how they suck, at least in the smaller sizes. Most AFR fans will even admit that.

Far as mufflers I use Dynomax Ultraflos and resonators and get frequent comments on how QUIET the car is. The resonators are just tiny glasspacks.

 

Can you send me a PM with the info about the resonators?

 

I agree with you on the muffler topic. I laugh when folks tell me the FM mufflers on my BBC Chevelle are costing me HP. What a crock.

 

This is why you see me tell alot of guys starting out to leave the stock catback on the car and change the muffler to a single in/out design with a turndown, makes as much power as many high dollar catbacks do.

David

 

As the one that brought up the Flowmaster thing in the first place, I feel obligated to clarify what I was saying.

Flowmaster in general doesn't suck. One of the Flowmaster catback systems for 4th-gen F-bodies, however, has been shown to flow worse than the stock Z28 exhaust. I'm not sure exactly which one it was; there are at least three different kits.

 

I like the idea of porting the heads. At this point getting rid of the heads is out of the question because as some of you have already pointed out they are expensive. I am open to all ideas on changing the cam and the valvetrain setup as well. Please possitive feed back only I get the point the heads suck.

 

dont know for sure but i dont see where the AFR's could be the problem i've seen them work wonders in other applications

 

Best advice I can give you is to remove your AFRs and send them to a reputable porter of your choice. With 180cc ports, there is a ton of room for improvement without going too big. I think that would get you the #s that you're after for sure.

While you're in there, I'd replace that cam too. Doesn't sound like TPIS know how to pull very good power out of an LT1 to me.

 

E85 makes more power than regular gasoline?

 

e85 is a higher octane rating and allows for more timing

 

One example:

https://www.camaroz28.com/forums/sho...d.php?t=595613