TXCAMSS

iTrader: (60)

I currently have 1 7/8 Kooks with the Kooks 3" Y-pipe, I-pipe, Dynomax dual dual set up with dual 3" cut-outs with 12" extensions. I drop the cat back when racing for weight reduction, but the I and Y-pipe are still in place. I'm going to keep this system for use most of the time since it's extremely quiet and comfortable to drive, plus it sees a lot of street use.

I have ran a best of 10.28 in hot humid air and I'm trying for a 9 second pass. I should be able to pull it off with good air alone, but I'm thinking I might be able to make it easier by swapping to a dual muffler directly off the collectors with the weight savings (if there is any) for track and max effort use.

Does anyone know what the I-pipe and Y pipes weigh? Would there be any gain or loss from going to a Magnaflow/Borla XR1 strait thru design over the dual cut-outs?

I'm hoping someone has been there and done that.

Can ya help a brotha out

JL ws-6

iTrader: (50)

unless you are planning on using the more race orientated setup on the street... why not just remove the system and run the headers open? That would net you the best weight reduction. If back pressure is a concern.. maybe a set of extensions only off the collectors might help, but I'd try the thing with the headers open first, that's the cheapest way to get to where you are trying to get to... unelss your track has a noise regulation or some other reason you have for wanting the muffler.

TXCAMSS

iTrader: (60)

That's a good point, but I don't own a trailer and we drive it quite a bit. I may try it on a TNT weekend when I have the time to drop it all at the track, but the I-pipe is a B@#*H to get off without a lift.

Want to take a stab at what the Y-pipe and I-pipe weigh? I'm guessing 30#s maybe?

I still have a good bit of weight in the car with the PS, stereo and stuff, but there's some things I'm just not willing to give up since it's a street car that loves the track.

Thanks for the input man!

Pro Stock John

iTrader: (34)

Post your combo, raceweight, and your best timeslip.

SPEEDYws6

iTrader: (9)

Have you listened to any of the cars running magnaflow oval muffers on the collectors? IMO, It's the best of both worlds... It flows great and is still not too loud.

TXCAMSS

iTrader: (60)

PSJ- I'll try to find the time slip and scan it tonight. It's a HK Enterprises (Erik Koenig)built NA 408 iron block with Greg Good ported ETP 5.3 heads with a 248/252 hyd custom grind cam.

3440s Race weight (last time out)
Rossler 4L60E
Custom built converter built by circle D (triple lock up)
12 Bolt Moser with 3.73s and a Tru-Trac locker
Home ported FAST 90mm intake
NW 90mm TB
Kooks 1 7/8 non stepped headers
Stock rockers
Morel lifters
42# injectors
PA K-member
Strange front brakes
BMR TA, SFC and relocation brackets
MadMan LCAs, Travel limiters and tuning
QA1s all 4 corners
HPTuners tuned in speed density
Pioneer front speakers and stock Monsoon system
Weld drag lites all the way around

Here's a link to the engne details:
https://ls1tech.com/forums/showthrea...hlight=grocery


Speedy- I haven't heard the Magnaflow ovals yet. How is the clearance? I don't want to have to beat or cut the floor board. Picky bastard ain't I LOL

SPEEDYws6

iTrader: (9)

Well, the clearance is great after you make room, lol (I said to hell with the floor after my 9" poked a nice hole through it) So I guess those are out. My next move would be a custom y-pipe with dual cut-outs and an XR-1 dumped at the axle.

SlickVert

iTrader: (5)

OK, I just weight mine.
I have a Stainless Steel custom Y that I made.
It comes off the headers with 3” SS into a Flow Master Merger 3 into 3.5 then into a 3.5 cutout the tapers down to 3” just prior to going over the rear end, that weighs 25lbs

My Total Y and I pipe just prior to going over the rear, with out the cutout valve is 25lbs.
Over the Axle Pipe in SS and it is 7lbs
Corsa SS and it is 26lbs
Electric Cutout and turndown is 2lbs
Total from the Header collector to the tailpipe is 70lbs.

When I made I system I was very careful to keep the weight down that is way I use SS except the Merger and Cutout. For a similar system made out of aluminize steel I am guessing maybe 10 to 30lbs more.
Hope that helps

My next exhaust system for the stroke will be 3.5 18 extension straight into dual 3.5 cutouts then into a 3.5” Y with Flow Master Merger then over the rear-end into Corsa.
I will build it so it will be easy to drop everything after the Cutouts.

Bob

TXCAMSS

iTrader: (60)

Speedy- Were you able to just slide the Magnaflows over the collector and use the same Kooks clamp? I'm still kicking the idea around.

Slick we have about the same set up. I actually have 3 - 3" cutouts. I could probably drop about 30#s if I removed the Y and I-pipe, but that's about what a set of Magnaflows would weigh I'm guessing.

Running open headers would save me .3-.4 if I was willing to trailer it, but that's what makes it stand out from the rest. We drive to and from the tracks, swap tires, drop the exhaust, uncap it and race. I'm starting to get good at it. lol.

Thanks for the replies and going through the trouble of weighing that stuff. I appreciate it.

JL ws-6

iTrader: (50)

maybe just modding the exhaust and putting a coupel 3 bolt flanges in that would be easily removable at teh track is an option? With those at the headers, and splitting up the back of the exhaust, you could probably get teh thign off with help of a buddy in about 10 min, and easily put it back up too.

Just a thought, and it would probably be an inexpensive thing to do too.

SlickVert

iTrader: (5)

You and I are on the same page.
I drive there change the tires, hit the electric cutout run in the 10's, swap bact to street tires, close the cutout and drive home.

You got to love it.
Real street cars.
Bob

SPEEDYws6

iTrader: (9)

Well I really don't have any experiance with kooks, I am running QTP's and the collector is 3" I.D. and the magnaflow is also 3" I.D. so I had to use an expander on the magnaflow to get it to slide over the collector. And then I just put a regular exhaust clamp on there. I also heat wrapped the drivers side muffler to keep the fuel/brake lines cool.

TXCAMSS

iTrader: (60)

PSJ- Here is one of the time slips! It's the quicker one, but the 60ft was a little weaker (deep staged a bit ) It looks like it would have run quicker if I'd been able to match the 1.36 60ft. The air is getting better by the day so it's going to get real interesting in the next few months.

It's not real clear, but if you enlarge it, its much clearer.

I'll try to sharpen it up a bit on my other PC.

SlickVert

iTrader: (5)

Very Impressive
What is your race weight?
Bob

V6 Bird

iTrader: (15)

Mine did the same freaking thing. Weird aint it.

Pro Stock John

iTrader: (34)

Nice. If you want to really showcase what a street car can do, you should run duel electric cutouts, with a light muffler setup. If you could pull another 50-100 lbs out of the car that would be great too. In the better air you should get really close to the 9's.

CHRISPY

Dual cutouts in the Ypipe can hurt performance a lot with the cutouts closed in normal driving. I'd just use the single electric in the intermediate pipe.

TXCAMSS

iTrader: (60)

Slick- The lightest I've been able to get the car is 3446#s and thats was with th tank almost empty. I don't like running it that low, but I was running a bracket race and didn't want to change the weight much unless I had to.

SlickVert

iTrader: (5)

Awsome ET and MPH for you weight.
You have your car working good
Bob

Ben R

James,

a true-dual exhaust going through some type of race muffler, with a cross-over pipe connecting the two sides would be the best for you. It's not really practical if you want to street drive the car, as it would be pretty loud and the cops might not like it, but it would be much better than a Y or I pipe.

I think if you upgraded to a really nice torque converter you'll see 9's this winter! What RPM are you crossing the traps at?