I already said I am not going to do the true duals setup. Besides, I would definatly loose power switching from a Borla to a Flowmaster.

CHANGE: Comments welcomed if you have specific knowledge of exhaust on an FI setup, or knowledge specific to my exact question.

I am starting to think I should have just asked this in the FI section, and not the Exhaust system section.

 

well, i do happen to have a friend w/ a F1-sc that gained over 30rwhp by switching from a catback to duals w/ flowmaster 1 chambers.

Otherwise, i think the best way to gain more power would probably be just add a cutout.

 

You should check with SSANDTA on EFA or maybe he's also here and on LS1tech...He runs 9.0s with a supercharged LT1 396....His name is Jeff..was on Pinks, too, I think...I'm guessing he's running TDs, though...

--Alan

 

Thanks for the inputs, but you guys aren't listening. I am not going to run true duals, nor do I want to. I just wanted to know what the best flowing exhaust for my current setup would be (keeping in mind I am not wanting to swap to true duals).

 

just pull off the muffler, and put in a xr1 bullet in the intermediate pipe, then have your shop fab up a dual exit or something.

 

I went with EngineerMike's suggestion for my Catback. I have Hooker LTs into Mufflex 3" Y pipe w/ 4" merge. From there it necks down to 3.5" Mufflex system with a Magnaflow 12909 straight-through muffler with a single 3.5" outlet. According to Mike, this system flows very well. Problem w/ most 4" mufflers is that they are very loud since most are race mufflers. Mufflex has a 4" system but the SpinTechs and Flowmasters are more restrictive than the Magnaflow. But, if you want a 4" system, get the Mufflex pipes and put on your own muffler. 3.5" should be good for your HP level though. Also, if you want dual exits, same side I think, Magnaflow makes something for that also.

 

CALL911, if you go back to the "best" exhaust thread, and scroll down to post #6, I have pics of my y pipe with merge collector on there. Also, if you scroll through my WebShots, there are more pics of my exhaust. I’m running Kooks 1 3/4 to 1 7/8 LT's, to a 3" Mufflex y pipe with a dual 3" to 4" merge collector (built on the car at Mufflex by Denny) to a Mufflex 4" catback with a 40 series 4" Flowmaster race muffler. I don’t think you can get much freer flowing than that without going to a dual 3” setup.

So you are saying in your previous post that you dynoed your car with a Mufflex 4", and switched to a Hooker 3" and gained power? I find that kinda hard to believe. If you can recall a former board member George Baxter, he was running Hooker LT's to a 3" y pipe to a Mufflex 4" catback going well into the 9’s and over 1200 RWHP. I believe at one time he had the Mufflex removed, installed a pair of bullets with turndowns, redynoed, and gained nothing. If Injuneer chimes in here he will verify that. His car was 383/Vortech YSi if I remember correctly.



Nick

 

Sorry to bring up an old topic, but where are you guys buying your Dual 3"-4" merges' at? I looked at Summit/Jegs, and nothin'...Is it just Mufflex, that makes them like that? (dual 3"-single 4")..

Call911-What did you end up going with?

 

Staying with my Hooker LT's, 3 inch hooker Y, into my Borla.

And "yes" I did gain power after swapping the 4 inch mufflex out to the 3 inch hooker Y. It never made sense to me to have to go from a 3 inch header, into a 4 inch Y, then through a reducer back down to the 3 inch cat back. I can see if perhaps it was a FI car well over 800 to the wheels, and it followed the 4 inch Mufflex into a 4 inch exhaust, but dyno results for me said I was better off keeping it all 3 inch.

 

What would help you is the stepped 1 7/8 Kooks LT's, Kooks Y, and keep your borla. Since you do not want to mess with TD's even though that would be the best option, I'd go that route. I recently just bought some Kooks LT's to replace my Hooker LT's. I do not understand why you don't have stepped LT's to begin with???

Wouldn't be surprised if you picked up 10 hp with stepped LT's on your current setup.

 

Here is the y collector that I used for my exhaust. Its a dual 3" for 4".



http://store.summitracing.com/partde...5&autoview=sku



Nick

 

The Hooker headers I have ARE long tubes. Granted they are 1 3/4 primaries, and not 1 7/8 primaries. I know I would probably pick up 10 RWHP by going with some Kooks 1 7/8's, but at this point having a sound tune already done to the car as it is, and the fact I need to stop dumping money into it, and keep saving for other things.

I am currently getting ready to start modding my Formula, and after that, there is another car I want to buy. If I don't stop modding the Z, these things will never be possible. Not to mention this thread is now very old, and honestly I'm not really interested anymore in considering changing the exhaust. Perhaps years down the road when I have some extra money to spend.

 

ha..didn't realize how old this was...sorry about that man. I must say you've invested quite a bit in your camaro. I'm sure I'd probably get a sick feeling if I saw the total price in money you've spent + man hours. One of the cleanest silver z's hands down I've ever seen.

As for the formula, why not just keep it stock? You've already got a 614hp car, what else do you really need? Since I don't see a firebird/TA ever being made again, why not let it be an investment? That way you get rewarded someday in the future for putting the time and money into that camaro.

Just my .02

 

Everyone goes their own way, and has their specific ideas and feelings about doing something. For me, having an LS1 that is very capable after just a few mods, seems foolish just to leave it stock. I will have 50 more RWHP by just doing H/C/I and bolt ons in the firebird than when I had my LT1 fully forged, and stroked into a 383 (back when it was N/A) for a fraction of the price. Having a Formula Ws6 (which they only made about 200 of) is a rare car, but I don't ever plan on selling either, so the re-sale value is un-important to me.

 

I've installed a Mufflex 3 1/2" single with Spintech chambered Muffler behind a Random tech dual 2 1/2" Y with cats. The Chambered muffler was alot of flow restriction for a 383 - D1. Made my own 3 1/2" pipe with a 3 1/2" qtp cutout. That worked. I recently took the "hi_flow" cats out since they were blown to pieces under the D1 exhaust load. ALso, I have actually blown the pipes (Muffllex 3 1/2" cat back) apart @ the clamp joints. I welded 3/8" threaded rod to hold it together. Their band-type clamps do not hold under FI pressure. I'm always changing, modding, and... learning! Glad I got a MIG welder. Now, I may go to a DynoMax UltraFlo Welded muffler (only $80 dollar @ Summit). It's my hobbie!!! Ha. B. (97ss - 383 - D1 - M6)