gomer

iTrader: (13)

I went any had my car dyno'd Friday after doing another head swap. I have always dyno'd my car thru a cutout in the I pipe right before the pipe goes over the rear axle, I do have a 24in bullet in the I pipe before the cutout though. So, while I was there I decided to dyno thru my full exhaust, which is a B&B tri-flow. It dyno'd 436rwhp and 389rwtq thru the full exhaust. That really surprised me. I knew the cutout was worth a good bit on a H/C car, but opening it up on the next run gave me 449rwhp and 406rwtq. That's a gain of 13rwhp and 17rwtq After talking to the dyno operator and several of the other guys there, none of them had ever seen or heard of a H/C car breaking 440rwhp with a full exhaust. I'm talking about a single over the axle pipe and single muffler, not a true dual setup.

Also, my car was running kinda rich 12.6:1 A/F compared to the last time I dyno'd, with very similar heads. What would cause my car to go from 13.1 to 12.5 and 12.6 A/F in the matter of two months?

I'd like to see some numbers of cutout open vs. closed on the same day on H/C cars if you have them. Please list you exhaust configuration and location of your cutout and if it is a single or dual cutout setup.

I know this "technically" belongs in the bolton section.. but I'm only looking for input from H/C guys.
Thanks

9T9BlueTA

iTrader: (2)

I am assuming no cats?? I would be interested to see if cats have a big part to play also. If you had cats restricting the exhaust I dont think the cutout would make that big of a difference. If you do have cats...well I am wrong oh well.

gomer

iTrader: (13)

My car does not have cats on it, Hooker long tubes, Jet hot offroad Y pipe, B&B tri-flow with a 24in bullet in the I pipe and a single cutout right before the pipe goes over the axle.

Kurtomac

iTrader: (5)

im going to the dyno this week my car is an 02 so ls6 intakei just have a wussy 224 224 581 581 112 cam jet hot lt's ORP TEA stage 2 5.3's 11:1 CR ASP pulley Corsa catback.....no cutout i need one tho as you have made me a believer...i dynoed 396rwhp 389rwtq cam only i since added the heads which are cut .016 and the pulley.....now what is gonna hurt me is the moser 12 bolt that i added with the 3:90's so im still lacking the ported tbody and the cutout but anyways im shootin for 430rwhp next time on the dyno add a cutout and tbody and might crack 440rwhp with this wussy cam of mine

beardWS6

iTrader: (1)

you can see in sig what I have. I`m running rich and pulled timing for the spray and I pulled 414rwhp with A4,stall, and 12-bolt with 3.73 gears threw FLP with ORP and corsa. Full exhaust except cats. If mine was a 6sp and tuned just for motor I think I would be there! Now if I was tuned just for motor now I think I would pull 425-435rwhp. Not bad for a A4!! I have MTI`s S2 heads and X1 cam, hope that helps. Now on spray she pulls sweet!

Kurtomac

iTrader: (5)

what the difference with the new heads gomer?

Kurtomac

iTrader: (5)

i need to put some of those ls6 heads and a man cam on my car and maybe ill put down some crazy numbers this thing has always dynoed high....338 350 lid catback 396 389 cam and headers and we'll see what i get now maybe patriot will let me try out some of thier heads on my car to see what they'll do put out some big numbers and people will be impressed= money for PP...hmm

gomer

iTrader: (13)

Excellent, have you ever tried a cutout? If so, what did you gain over your exhaust setup? I have done some research and the Corsa seems to be doing very well on H/C cars

gomer

iTrader: (13)

The first set of LS6 style heads I had were a "prototype" set that were not heat treated and didn't have the "dual quench" combustion chamber. I swapped them out for the "shelf stock" type of head that is being sold now. When you dyno your car, please try it without and with the cutout open, I'd like to see how much it gains on your setup with your exhaust. I'm really interested in yours since you have a Corsa.
Thanks

offaxis

iTrader: (19)

Hey Gomer

This is not what you are looking for but I can tell you when I was running the TR220 cam only set up I would gain 15 hp bypassing the muffler completely ( like a cutout )on my borla system. When I switched to the dual exhaust I picked up another 7 hp over the bypased muffler.I actually have 2 dumps on my dual ehaust about 12 inches after the headers but I have not opened them on a dyno or at the track yet so I dont know what kinds of gains there might be. Anyway I figured you might like this sort of info to get ya thinking of some duals. I bet with your h/c setup there might be another 10 hp or so hidding in there.

Jeremy

Slowhawk

iTrader: (12)

443hp/412tq with my setup with FLP's,Corsa catback.Gained 1hp when I opened the cutout.

Kurtomac

iTrader: (5)

yea i dont think ill gain all that much.....corsa has to flow really well condsidering its damn near the same volume as an open cutout LT header Car.....gomer did the bullet really get rid of the rasp much.....deepen it up, quiet it up any?

gomer

iTrader: (13)

Yeah, the bullet really killed the rasp in my car and made it a good bit quieter. In fact my car is VERY quiet as compared to any other Fbody I have heard with longtubes and offroad Y.

The corsa is looking really good right now.. the ol' B&B may be for sale soon, it just kills me knowing that I'm giving up that much power for "being quiet"

WhiteDiamond

My 98WS6 dyno'd 432rwhp and 398rwtq through full exhaust, Borla, and high flow cats. It had stage II LS1 heads and a B1 cam with full bolt-ons and some computer tuning.

Todd

2001 Pewter WS6

iTrader: (43)

The Corsa flows really well. Damn near straight through. At the track I necer really saw a difference going through the cut out or out the Corsa. I know that the FLP Y pipe will slow you down. I am looking to that mine replaced.

99 Black Bird T/A

iTrader: (4)

I had several dyno pulls where the cut and SLP dual/dual were with in 1rwhp of each other with coated Hooker LT's, no cats, Mufflex Y pipe, 3 inch cut out in front of rear axle.

The cars best dyno pulls are listed in sig for SLP dual/dual & cut out.

As for Billy Boat and his exhaust...when he mailed me a claim stating up too a 50rwtq gain with his exhaust over stock, I knew he was full of it.

glhs379

iTrader: (1)

Wonder what a cutout would do over my magnaflow?

Damian

iTrader: (89)

Gomer, B&B is one of the worst flowing catbacks on the market. Sounds excellent, but doesn't flow worth a ****. That's why you gained so much with the cutout. A buddy of mine lost 20 rwhp through his B&B compaired to a cutout on a Cam only car....Nice #'s through full exhaust though...

I just dyno'd my car today through full exhaust as a matter of fact. Made 449/403 completely capped and still untuned. A/F richen'd up a bit on the dyno, so i'm guessing 450-455 rwhp through full exhaust and tuned shouldn't be a problem with my setup. I've got a gremlin right now cause a dip @ 6K so I was trying to dyno and see if it went away or not.........in case anybody was wonderin

This is through a Hooker catback. Anybody @ the TR crew will tell you this is one of the best flowing/sounding catbacks on the market, bar none. With bolt ons, I only lost 2 rwhp going through the catback vs. the cutout..


Josh

Beast96Z

iTrader: (21)

Magnaflow supposedlly only looses 1-2 hp over a cut-out so I've read in a few posts. In case you were looking for a cheaper alternative to the corsa.

Slowhawk

iTrader: (12)

Here is a few runs and how the exhaust worked on my setup

FLP/Corsa=443hp/412tq
FLP/cutout=444hp/410tq
FLP/SLP dual dual=415hp/385tq
FLP/Corsa/Bullit=435hp/405tq

As you see the SLP kill's power,but I run an electric cutout when it's on the car for daily driving.At the track I run the Corsa.The Bullit was added because with my Cam and 11.2-1 compression the Corsa would give bad ressinance inside the car...
I test everything at the dyno and track,over 90 runs on my car......