Horse Power just talking
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Burning Brakes
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From: I live in Findlay Ohio
Horse Power just talking
Just for talking. With the X pipe, No Cats,Chip and RMB what would you say my HP is. 928 Motorsports has dyno proof that I will gain 26 hp for the Xpipe and they also say 10 hp for the RMB. Autoathority says a 30 HP gain for the chip. This comes out to about 66 more hp for a total of stock at 316 + the 66 for 382 HP would this be a fair number. I know I should Dyno it but that is not going to happen right now. I really only want to know so I can rub it into my buddy who has a 69 Nova SS which is a very nice car.
Cliff 87 S4 Auto
Cliff 87 S4 Auto
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From: Orange, Cal
Wow, if advertised HP gains could be added up that would be sweet. Best thing is weigh the car and run a 1/4 mile a couple times and see what the numbers work out to. Something like a DynoJet gives worthless absolute numbers for a auto transmission car.
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The Chip is usually not too effective on an S4. Stock RWHP is 260-270 range, although I think 270 is rare for an S4. You might hit 290-300 RWHP with your mods, although 300 is very unlikely. Hope for 290 and be happy if it is close. Powetrain loss is estimated at 15 to 18%, so crank HP would be about 353 versus 316 quoted for stock.
My S4 was 262 stock on the dyno (Dynapac). So, 18% loss would say I was 319 crank. I think the loss is probably slightly less and the 316 factory number is pretty good. Higher numbers often reflect differences in dyno machines.
My S4 was 262 stock on the dyno (Dynapac). So, 18% loss would say I was 319 crank. I think the loss is probably slightly less and the 316 factory number is pretty good. Higher numbers often reflect differences in dyno machines.
Last edited by Bill Ball; Jan 25, 2007 at 12:59 AM.
Three Wheelin'
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From: Mosier, Oregon
Originally Posted by Wolf Pack
Just for talking. With the X pipe, No Cats,Chip and RMB what would you say my HP is. 928 Motorsports has dyno proof that I will gain 26 hp for the Xpipe and they also say 10 hp for the RMB. Autoathority says a 30 HP gain for the chip. This comes out to about 66 more hp for a total of stock at 316 + the 66 for 382 HP would this be a fair number. I know I should Dyno it but that is not going to happen right now. I really only want to know so I can rub it into my buddy who has a 69 Nova SS which is a very nice car.
Cliff 87 S4 Auto
Cliff 87 S4 Auto
The X pipe will give you the most consistent gain on an S4 of anything else for the $$ spent.
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You cant add each HP "add on" to get a cumalitve total...would be nice
They will all interact with each other differently.
Thats interesting about the X-pipe and the RMB Louie. I think it kind of proves what im saying above. A stock S4 with cats may see a gain from adding JUST an RMB...but an S4 that already has an X pipe may not. As im in the midst of a little sound reduction work, makes me wish i hadnt ditched my stock rear muffler reading that now
!
I had a chip burned for my S4 but it only rasies the revlimiter to a GT, nothing else (still has S4 idle)...gets my 60mph in 1st gear with out banging on the rev limiter. It also gives more wiggle room on a down shift at speed.
They will all interact with each other differently.
Thats interesting about the X-pipe and the RMB Louie. I think it kind of proves what im saying above. A stock S4 with cats may see a gain from adding JUST an RMB...but an S4 that already has an X pipe may not. As im in the midst of a little sound reduction work, makes me wish i hadnt ditched my stock rear muffler reading that now
!I had a chip burned for my S4 but it only rasies the revlimiter to a GT, nothing else (still has S4 idle)...gets my 60mph in 1st gear with out banging on the rev limiter. It also gives more wiggle room on a down shift at speed.
Three Wheelin'
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From: Mosier, Oregon
Originally Posted by Tony
You cant add each HP "add on" to get a cumalitve total...would be nice
They will all interact with each other differently.
Thats interesting about the X-pipe and the RMB Louie. I think it kind of proves what im saying above. A stock S4 with cats may see a gain from adding JUST an RMB...but an S4 that already has an X pipe may not. As im in the midst of a little sound reduction work, makes me wish i hadnt ditched my stock rear muffler reading that now !
I had a chip burned for my S4 but it only rasies the revlimiter to a GT, nothing else (still has S4 idle)...gets my 60mph in 1st gear with out banging on the rev limiter. It also gives more wiggle room on a down shift at speed.
They will all interact with each other differently.
Thats interesting about the X-pipe and the RMB Louie. I think it kind of proves what im saying above. A stock S4 with cats may see a gain from adding JUST an RMB...but an S4 that already has an X pipe may not. As im in the midst of a little sound reduction work, makes me wish i hadnt ditched my stock rear muffler reading that now
!I had a chip burned for my S4 but it only rasies the revlimiter to a GT, nothing else (still has S4 idle)...gets my 60mph in 1st gear with out banging on the rev limiter. It also gives more wiggle room on a down shift at speed.
A stock S4 with cats will see no difference whether it has the rear muffler or not. The restriction is at the front of the system (cats) and changing the downstream flow capacity a little won't change the total. I saw no change whether I had the rear muffler or RMB when I had the X and no cats. The rear muffler just doesn't affect the power. On a SC car with much greater flow, it might. With the X on and no cats, it made almost no difference whether I had the small resonators or the larger early S4 resonators. For my taste, the exhaust was too quiet with large resonators and rear muffler. I settled on a GT rear exhaust. That is, small resonators and GT rear muffler. The S4 rear muffler was equal in power, but I liked the dual exhaust tips of the GT rear muffler.
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From: Las Vegas
Originally Posted by heinrich
Louie, why bother with the rear muffler? Just put the X; S4 mids and RMB on for wonderful sound and torque 
Besides the stock rear muffler has anyone used a different muffler? dual in-dual out? Dual in -single out? I know the stock unit weighs an FN ton!
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You're gonna hate hearing this Tony but I agree. On an automatic, or on long long trips in 5th gear. However a manual gearbox has the engine cycling revs so constantly that the irritating rev range is very seldom, and only for short bursts, encountered.
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From: Mosier, Oregon
Originally Posted by heinrich
Louie, why bother with the rear muffler? Just put the X; S4 mids and RMB on for wonderful sound and torque
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Yeah unfortunately you dont get to add 30 hp for this 20 for that 15 for that to equal what your end result will be. Typically most claims are exadgerated. Although i know one so cal 928 owner (larry) that swears by his chip in his car. He says his car had i think 290 rwhp when dynoed with an rmb, chip, and x pipe. Thats pretty damn good for an S4.
I did however watch an episode of the show "Trucks" where they did all this crap to some diesel, said 200 hp for this engine program, 50 for this exhaust, 15 for this intake, 150 for this propane injection sytem and said, yeah it should all give us an extra 415 hp. I was like yeah right you idiot. Low and behold they did all the stuff, put it on the dyno and this fricking diesel truck cranked out like 700-800 HP and like 1200 ft.lb torque. It surpased the manufacturers claims. I was sshocked. But, dont count on just adding up what each manufacturer tells you for a final gain, it wont work. Except in this case i stated above.
I did however watch an episode of the show "Trucks" where they did all this crap to some diesel, said 200 hp for this engine program, 50 for this exhaust, 15 for this intake, 150 for this propane injection sytem and said, yeah it should all give us an extra 415 hp. I was like yeah right you idiot. Low and behold they did all the stuff, put it on the dyno and this fricking diesel truck cranked out like 700-800 HP and like 1200 ft.lb torque. It surpased the manufacturers claims. I was sshocked. But, dont count on just adding up what each manufacturer tells you for a final gain, it wont work. Except in this case i stated above.
Race Director
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From: Stockton, CA
The easiest and cheapest way to boost HP in an S4 is an Xpipe.....typical gains seem to be in the 20+ range......made by several different suppliers...RMB is more of a sound gain....but might be too loud with an Xpipe.....
Drifting
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I run the H-pipe and RMB with the S4 Resonators, quite loud at 4k but mostly mild everywhere else. A lot of fun for showing off to the crowd at car shows with a rev or two. But I defineitly lost low end torque. Can't even spin the tires from a dead stop, could be the clutch going south. But once it hits 3k rpm it shoots like a rocket. I'm going to dyno this spring so we'll see what my baseline is with this set-up.
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Originally Posted by IcemanG17
The easiest and cheapest way to boost HP in an S4 is an Xpipe.....typical gains seem to be in the 20+ range......made by several different suppliers...RMB is more of a sound gain....but might be too loud with an Xpipe.....
