Help!! Got a few simple question on S197 exhaust for whipple car
09-13-2008, 03:21 PM
#1
Thread Starter
Join Date: Apr 2008
Posts: 41
Help!! Got a few simple question on S197 exhaust for whipple car
Getting ready to install whipple... got a few question about exhaust.
At this point, I DON'T want to go with Long Tubes... maybe later... but NOT interested right now...second, I want to keep some sort of legal cat pipes, not interested in changing out h or x pipes without cat's every two years for Maryland emissions tests...
All that I would LIKE to do is an axle back system... leaning towards Flowmasters...
questions:
1. Is there any benefit at all going with a Cat-back system over an axle back? It appears to me the factory pipes from that go from the cat-pipe connection to the axel backs are 2 1/2 inches and the after market cat-back pipes are also 2 1/2 inches... so is there any real benefit? smoother bends on aftermarket??
2. Is there any benefit at all changing out the factory h-pipe (w/ cats) and going x or h-pipe w/ aftermarket cats?
3. How loud would the my exhaust be if I kept the factory h-pipe and went with the straight pipe (no muffler) axle-back exhaust? that seems to be the cheapest?
4. With a 450 rwhp whipple under the hood, how much improvement in HP would any axle-back system be over the stock exhaust?
thanks
At this point, I DON'T want to go with Long Tubes... maybe later... but NOT interested right now...second, I want to keep some sort of legal cat pipes, not interested in changing out h or x pipes without cat's every two years for Maryland emissions tests...
All that I would LIKE to do is an axle back system... leaning towards Flowmasters...
questions:
1. Is there any benefit at all going with a Cat-back system over an axle back? It appears to me the factory pipes from that go from the cat-pipe connection to the axel backs are 2 1/2 inches and the after market cat-back pipes are also 2 1/2 inches... so is there any real benefit? smoother bends on aftermarket??
2. Is there any benefit at all changing out the factory h-pipe (w/ cats) and going x or h-pipe w/ aftermarket cats?
3. How loud would the my exhaust be if I kept the factory h-pipe and went with the straight pipe (no muffler) axle-back exhaust? that seems to be the cheapest?
4. With a 450 rwhp whipple under the hood, how much improvement in HP would any axle-back system be over the stock exhaust?
thanks
09-13-2008, 03:53 PM
#2
3rd Gear Member
Join Date: Jan 2008
Location: Arizona
Posts: 598
I am going to reply to this IMHO. Just to let you know, I have an h/o whipple car at 11psi.
1. the only way I would say a cat-back system is going to be worth it, is if you step up to 3". To go from factory 2.5" to aftermarket 2.5" isn't going to change night into day. Most people will agree that Ford did a very good job with the factory exhaust, with the exception of the axle-backs (and it's not that they did BAD, but they are just queit, as one would expect with stockers.) I say leave the stock mid pipes.
2. I personally got rid of the stock H and went with a Bassani X with high flow cats. A little more breathing room right after the manifolds, legal, and the X really smooths out the exhaust note. Now, was it worth it? I think so. Because I can notice a sound difference and with the high flows in there, I would say it is something to consider.
3. Your exhaust won't be quiet, but if you leave the cats, it won't be over bearing. I have driven one with straight pipes, and it was fun for a short drive. Wouldn't do it on a daily driver, but thats me. You might like that.
4. An absolute improvement. The stockers are restrictive, and you will hear it when you punch it with that whipple. You need some breathable mufflers, as you are going to be pushing a lot of air.
Hope this helps.
BTW, in the fore-sale forum (shameless plug) I am selling some excellent condition Borla/FRPP stingers! Check em!
1. the only way I would say a cat-back system is going to be worth it, is if you step up to 3". To go from factory 2.5" to aftermarket 2.5" isn't going to change night into day. Most people will agree that Ford did a very good job with the factory exhaust, with the exception of the axle-backs (and it's not that they did BAD, but they are just queit, as one would expect with stockers.) I say leave the stock mid pipes.
2. I personally got rid of the stock H and went with a Bassani X with high flow cats. A little more breathing room right after the manifolds, legal, and the X really smooths out the exhaust note. Now, was it worth it? I think so. Because I can notice a sound difference and with the high flows in there, I would say it is something to consider.
3. Your exhaust won't be quiet, but if you leave the cats, it won't be over bearing. I have driven one with straight pipes, and it was fun for a short drive. Wouldn't do it on a daily driver, but thats me. You might like that.
4. An absolute improvement. The stockers are restrictive, and you will hear it when you punch it with that whipple. You need some breathable mufflers, as you are going to be pushing a lot of air.
Hope this helps.
BTW, in the fore-sale forum (shameless plug) I am selling some excellent condition Borla/FRPP stingers! Check em!
09-13-2008, 05:16 PM
#4
Thread Starter
Join Date: Apr 2008
Posts: 41
AZalloy... very informative...after the flowmasters... the borla stingers was my next choice... is there any real difference (except the tail pipe diameter) between the borla stingers and the FFRP borla stingers...
which ones do you have? and how much do you want for them... Arizona... long way to ship...don't know...
which ones do you have? and how much do you want for them... Arizona... long way to ship...don't know...
09-13-2008, 06:58 PM
#5
5th Gear Member
Join Date: Jun 2007
Location: Orlando, FL
Posts: 2,276
Tim
1. Cat back wont make any difference at your power level. Only thing that will change is the slight oval over the axle, but I wouldnt think there would be any difference in power.
2. Slightly better flow, but I would say most of the difference is in sound.
3. I have heard a few stangs with the muffler delete pypes and I did not like the tone of the exhaust. You might.
4. You will see 0hp from an axle back it is sound only.
And I also have a plug in that I am selling my pypes violators soon. PM me if interested. I like the sound but I am changing up the whole exhaust.
1. Cat back wont make any difference at your power level. Only thing that will change is the slight oval over the axle, but I wouldnt think there would be any difference in power.
2. Slightly better flow, but I would say most of the difference is in sound.
3. I have heard a few stangs with the muffler delete pypes and I did not like the tone of the exhaust. You might.
4. You will see 0hp from an axle back it is sound only.
And I also have a plug in that I am selling my pypes violators soon. PM me if interested. I like the sound but I am changing up the whole exhaust.
09-13-2008, 08:10 PM
#6
Thread Starter
Join Date: Apr 2008
Posts: 41
Alloy & GT0405... Thanks for taking the time to answer my questions one by one. I put this thread on 5 mustang websites... and so far this site is the only for anyone to answer my questions like I asked them...
The two of you gave basically the same answer except for no. 4. GT0405 said I would get zero HP from a axle back at the 450 hp level... and Alloy said there would be an absolute improvement... don't want to get you two fighting... but thought I would note that.
Some of the tuners I have talked to said somwhere in the middle... maybe 5 to 15 hp going with a less restrictive axle back on a whipple car making 450 rwhp...
CR at Tillman speed said he just dynoed a 470 rwhp 10 psi car that had 100% stock exhaust down to the mufflers...the car was 100% stock except for the whipple HO system...
The two of you gave basically the same answer except for no. 4. GT0405 said I would get zero HP from a axle back at the 450 hp level... and Alloy said there would be an absolute improvement... don't want to get you two fighting... but thought I would note that.
Some of the tuners I have talked to said somwhere in the middle... maybe 5 to 15 hp going with a less restrictive axle back on a whipple car making 450 rwhp...
CR at Tillman speed said he just dynoed a 470 rwhp 10 psi car that had 100% stock exhaust down to the mufflers...the car was 100% stock except for the whipple HO system...
09-14-2008, 03:07 AM
#7
5th Gear Member
Join Date: Apr 2007
Location: North Carolina
Posts: 3,070
The stock over-axle pipes are not 2.5" all the way. There is one place where the pipe has a flat spot crimped into it. An aftermarket catback system will not have that crimp.
Also, the stock H has a flat crimped spot where it bolts to the manifolds. It looks as if it was done for the O2 bungs. An aftermarket midpipe does not have this crimped spot.
I would say that a midpipe with high-flow cats is the way to go to increase flow.
Also, the stock H has a flat crimped spot where it bolts to the manifolds. It looks as if it was done for the O2 bungs. An aftermarket midpipe does not have this crimped spot.
I would say that a midpipe with high-flow cats is the way to go to increase flow.
09-14-2008, 10:23 AM
#8
5th Gear Member
Join Date: Jun 2007
Location: Orlando, FL
Posts: 2,276
Tim,
I have never really seen anyone show back to back dyno's that prove any hp gain from a muffler swap. There are too many variables in dyno testing, so a change of 5rwhp + or - doesnt mean much. ( I dont trust manufacterurer #'s)
I would say buy the one that sounds the best to your ears.
Also Warmachine is right, that is what I talked about in #1 in my first response. I just cant think they affect flow enough to impact power at 450rwhp. Start pushing over 500+ and the exhaust might be a restriction.
From my research even the stock headers arent that much or a restriction at this power level. You can make more hp, but $ per hp, you cant beat more boost after the initial investment.
I have never really seen anyone show back to back dyno's that prove any hp gain from a muffler swap. There are too many variables in dyno testing, so a change of 5rwhp + or - doesnt mean much. ( I dont trust manufacterurer #'s)
I would say buy the one that sounds the best to your ears.
Also Warmachine is right, that is what I talked about in #1 in my first response. I just cant think they affect flow enough to impact power at 450rwhp. Start pushing over 500+ and the exhaust might be a restriction.
From my research even the stock headers arent that much or a restriction at this power level. You can make more hp, but $ per hp, you cant beat more boost after the initial investment.
09-14-2008, 02:28 PM
#9
Thread Starter
Join Date: Apr 2008
Posts: 41
0405... thanks for taking the time to provide your opinion... How much boost are you running? I don't know if you saw my other post where I let everyone know that Mike at Whipple told me that the new '08 HO whipple kits will come with a 3.25 dia pulley making 12 lbs of boost...
Secondly, is that the HO kits for '08 will not be using open air filters... but will use the factory air box... and the pipe coming off the box will be cut-off and a new pipe slid over the existing pipe... looks like this could cause an inlet restriction...
Secondly, is that the HO kits for '08 will not be using open air filters... but will use the factory air box... and the pipe coming off the box will be cut-off and a new pipe slid over the existing pipe... looks like this could cause an inlet restriction...
09-14-2008, 03:44 PM
#10
5th Gear Member
Join Date: Jun 2007
Location: Orlando, FL
Posts: 2,276
Hmmmm that is a strange set up.
I dont think I like that intake idea. Hopefully someone will come out with a good replacement.
I am currently at 8psi making 420rwhp, but in about a month I am going up to 10psi and hope to be 450rwhp +.
I trust Whipple but 12psi is a little high to me on a stock SB. I would look into buying a 10psi pulley, but that is just me.
I dont think I like that intake idea. Hopefully someone will come out with a good replacement.
I am currently at 8psi making 420rwhp, but in about a month I am going up to 10psi and hope to be 450rwhp +.
I trust Whipple but 12psi is a little high to me on a stock SB. I would look into buying a 10psi pulley, but that is just me.