SpeedJunkee

So the S400 (84mm, 96mm turbine, Race V2 inlet, 1.10 T6) turbo is capable of 1300-1400 HP. I was hoping through my built 383 LT1 M6 car I could see around 1,000 at the tire. That being said, I don't want to sacrifice driveability and sounding too loud to enjoy driving it on the street with the windows down for power.

I have had a bad experience with cutouts leaking, and bending metal on a weaker setup in the past, and really just want to run the setup through a muffler. I currently have a Borla 3" exhaust and muffler. I was planning on running 4" pipe from the down-pipe to the Borla so it would still sound good, and not too loud.

How restrictive will this be though? At most, I could possibly do a different 4" muffler, but all the ones I have heard sound terrible. I really don't want to go the cutout route again with all the problems I had on a less power full setup.

Thoughts?

Kmspeedie

iTrader: (1)

in my opinion if your car is high enough to clear a 4inch all the way back and drive normally on the street.. you might have a truck... lol so just do a muffler before the cutout so u dont have 4inches of pipe running under the car..not many options for what you wanna do

SpeedJunkee

I really don't want to do cutouts. I just sold mine a couple months ago. They were not reliable for big power levels IMO, and don't want to turn the car into a racecar again with the way it sounds. Maybe the turbo won't be as bad as the blower was for the noise.

I've seen guys run the Mufflex 4" exhaust before plenty of times in 4th gens so I know it can be done. I think the Mufflex mufflers sound like crap, so I'd rather at least keep my Borla muffler.

Lil John was telling me some guy named Matt Ray on the boosted LSX Facebook page did a custom 5" exhaust on his F-body (although I am still trying to find it to see how).

DEFYANT

Why not run a 4" bullet and dump it? I've ridden in fender exit big turbo cars, and really you can have a normal conversation in them. Hell, my girlfriends V6 Mustang with Flowmasters is louder.

SpeedJunkee

You must have ridden in much different cars than me. The ones I rode in sounded like racecars with fender exit setups.

Just so we are clear, you are suggesting running a bullet style muffler, then a dump after the muffler?

SpeedJunkee

I guess the question I should be asking here is; what is the quietest way I can have a 4" exhaust without restricting too much power for the level I am (will be) at?

I looked into Borla's bullet style XR-1 mufflers. I have no idea now quiet they are in comparison to my current standard F-body 3" Borla cat back system.

Right now, I don't really want to explore cutouts/dumps. I want to find the best solution without that for now. If I do that, hit the rollers, and its obvious I am getting destroyed by it, I may rethink things then.

It may be just a matter of how loud things are also. I am more familiar with blower cars than turbo cars. My previous blower setup sounded like a NASCAR with cutouts. Its sounded tolerable but very loud through the Borla. The turbo even though capable of more power, should be much more quiet. It may end up being quiet enough were running a dump would not be that bad. But one of the main reasons I changed my setup was really just to keep things tolerable decibal wise, so the thought of running dumps is reminding me what I was getting away from.

josh4ku

iTrader: (10)

Well my setup has a 3" down pipe along with 3" to the back with magma flow. And I made 880rwho with the cutout open and 740 with it closed. It restricts badly with the cutout closed, also after a couple pulls with it closed the engine temp rises 210-215 with the cutout open engine temp stays around 185. The manga flow is way to quiet for me. I liked it with headers but not with a turbo.

SpeedJunkee

Thank you for the input. What sized turbo are you running and what boost level?

408GT

iTrader: (2)

I have an S480 on my LTD w/ a 4" exhaust all the way back. The car is very quiet and drives around great. Stock48 also has a full length 4" exhaust on his Nova that went 8.22 @ 164. If he can do that with his, then it's plenty for mine. Here's the muffler: http://www.summitracing.com/parts/mpe-14153/overview/

brandon6.0

iTrader: (32)

I run a s480 with full 4" to the rear with a dumped bullet. I think it sounds perfect. Not very loud at all. My old setup with longtubes and dual magnaflows 3" was way louder.

The turbo soaks up alot of the cam and exhaust sound.

turbo6man

iTrader: (5)

I have the s484 in my setup in signature but my t6 housing is the 1.32. I will tell you this, Every bend adds restriction. If you get to much differential pressure between pre and post turbine wheel on a larger exhaust wheel turbo like we have it will be a noticeable difference on how the turbo spools. I am only referring to the spool up (although I am sure it has effects on overall power to) I have tried 4" and 5" exhaust in the same configuration(two 45's and 2 90's and 5 and 1/2' long with one muffler) and the 5" will spool up to the two step noticeably faster.

SpeedJunkee

I'm gonna fit as big as I can. If I have room (and that's a BIG if), I may be able to do a 5" downpipe into a 4" exhaust to a bullet style muffler.

What cutouts do you guys run? Do any of you have sound clips of how your setups sound?

Sales@Tick

iTrader: (3)

Run the absolute biggest downpipe and exhaust system you can afford and physically fit in your vehicle.

You want as little post turbine pressure as possible so that unrestricted exhaust flow can occur. High pressure moves to low pressure always and the larger the pressure delta between pre and post turbine pressure there is, the more power you will make and the faster the turbo will spool.

SpeedJunkee

Thanks Martin. I believe you are absolutely correct, and that is the plan. If I can squeeze a 5" downpipe, I will. I don't think it's possible to squeeze a 5" pipe all the way back to the muffler, but I have seen 4", so I'm gonna make that happen as far back as possible to the muffler.

There's a lot of unknowns. I don't know how much more quiet the turbo will be over the blower setup. If it's really that much quieter I can revisit the dump/cutout idea.

I spoke to Borla and they said my current muffler actually doesn't flow any less than the XR-1 bullet race muffler does, but the race muffler is actually quieter.

Amyone have any WOT in car videos with these turbos and dumps?

josh4ku

iTrader: (10)

billet 75/75 20 psi with cutout open. drops down to 14 with cutout closed and spool time is a lot slower. After a few hard pulls with the cutout closed engine temp climbs over 200. with it open temps stay at 180-190