Flowmaster force II cat-back
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Burning Brakes
Joined: Jun 2005
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From: Hyde Park NY
St. Jude Donor '05
Flowmaster force II cat-back
I just had my 95 VERT outfitted with the Flowmaster force II cat - back exhaust system. from reading the online literature, it appears a performance gain of A typical power gain will be around 5%-10%, with increased fuel economy from 1-2 mpg. Has anyone with a flowmaster force II system on an LT1 engine, been able to verify these gains? I love the sound. Not too loud, but more meat then before. Just curious how many more HORSES , if any, I will have above my base 300. PS. i also run with an air foil in the TBI & KN air filter with open cover.
Cheers!
Cheers!
Last edited by RAGOVET; Jun 28, 2005 at 04:10 PM.
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Power gains aside, that is one good sounding system. Personally I've never cared for the Flowmaster sound but these sound great. I'd put the system on a less modified (than mine) C4 in a heartbeat.
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Hmmm, 5%-10% on a 300chp motor is 15-30chp gain; I would expect 15-20 to be more reasonable, especially with the stock choking cats.
A 300chp motor requires about 660cfm of flow before back pressure costs HP but the stock LT1 cats only flow around 200-250cfm each.
You might consider a nice pair of hi-flow cats as your next power investment.
A 300chp motor requires about 660cfm of flow before back pressure costs HP but the stock LT1 cats only flow around 200-250cfm each.
You might consider a nice pair of hi-flow cats as your next power investment.
Burning Brakes
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you mean the system that says in the MAM (among others)catalog"add a whopping 70 hp at the rear wheels'when the test lad added a performance chip,the rear wheel power was boosted by70 tire shredded horsepower!better get a new set of goodyears too!really,that must be some chip then 
maybe there in cahoots with goodyear. 
well in the june 98 issue of corvette fever,they did an exhaust comparo with most of the major manufacturers,on a 96 LT4.the flowmaster system gained a whopping 7 hp and 2 ftlbs torque @the rearwheels.now,granted,it might gain a little more on an LT1,because of the LT4's already,xpipe,but NOT that much more.its a good system for the money(Ive seen it for $550 from summit)and Ive had flowmaster mufflers on several of my vettes and f-bods,and I liked em,but thats an ourageous claim.
maybe there in cahoots with goodyear. well in the june 98 issue of corvette fever,they did an exhaust comparo with most of the major manufacturers,on a 96 LT4.the flowmaster system gained a whopping 7 hp and 2 ftlbs torque @the rearwheels.now,granted,it might gain a little more on an LT1,because of the LT4's already,xpipe,but NOT that much more.its a good system for the money(Ive seen it for $550 from summit)and Ive had flowmaster mufflers on several of my vettes and f-bods,and I liked em,but thats an ourageous claim.
Team Owner
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From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
Originally Posted by vette&f-bod lover
you mean the system that says in the MAM (among others)catalog"add a whopping 70 hp at the rear wheels'when the test lad added a performance chip,the rear wheel power was boosted by70 tire shredded horsepower!better get a new set of goodyears too!really,that must be some chip then maybe there in cahoots with goodyear. well in the june 98 issue of corvette fever,they did an exhaust comparo with most of the major manufacturers,on a 96 LT4.the flowmaster system gained a whopping 7 hp and 2 ftlbs torque @the rearwheels.now,granted,it might gain a little more on an LT1,because of the LT4's already,xpipe,but NOT that much more.its a good system for the money(Ive seen it for $550 from summit)and Ive had flowmaster mufflers on several of my vettes and f-bods,and I liked em,but thats an ourageous claim.
maybe there in cahoots with goodyear. well in the june 98 issue of corvette fever,they did an exhaust comparo with most of the major manufacturers,on a 96 LT4.the flowmaster system gained a whopping 7 hp and 2 ftlbs torque @the rearwheels.now,granted,it might gain a little more on an LT1,because of the LT4's already,xpipe,but NOT that much more.its a good system for the money(Ive seen it for $550 from summit)and Ive had flowmaster mufflers on several of my vettes and f-bods,and I liked em,but thats an ourageous claim.Still, go for it for the sound, not the "tire-shredding increase in horsepower".
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Sorry no data on the mufflers, just that flow data on the cats that someone put up not long ago when comparing hi-flow cats to stockers.
I think that a good muffler will out flow the stock cats and maybe flow as much as the hi-flow cats.
My concern was for the L98 cars with only that damn restrictive single cat. We really need to go to true duals like the LT1 guys if we go much over 300chp.
I think that a good muffler will out flow the stock cats and maybe flow as much as the hi-flow cats.
My concern was for the L98 cars with only that damn restrictive single cat. We really need to go to true duals like the LT1 guys if we go much over 300chp.
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Burning Brakes
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Originally Posted by LT4CompYell
Well, wait a minute. 7 hp at the rear wheels is about 10 or a little more (maybe 12?) at the crank??? That gets pretty close to the 15 hp claim which equates to a 5% increase of 300 hp LT1, right?
but its not the 80 crank hp(with a chip)claimed.btw,they also tested just a pair of the dynomax mufflers,that look identical to the stock LT1's.they were only $229 and they gained 5 rwhp and 3 rwtq.which equaled the $1800(i think that system is cheaper now though)borla system in hp and outgained it 1 ftlb in tq.ive been considering getting those dynomax's,as my mufflers are starting to look there 11 year age,and I want some more sound,but I cant seem to find em anymore,anyone?
Team Owner
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From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
OK, you win. Yes, it's a lot of money. But to me, if someone sez you're gonna gain 5% and comes close enough so that it could be a testing day/climate/machine used situation, I say they got it. And I could be wrong, but somewhere I've heard it said that horsepower doesn't come cheap; matter of fact, someone posted that each hp is/can cost $50. Sooooooooo, doing the math......
Burning Brakes
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no hp doesnt come cheap with these cars,and dont get me wrong,the flowmaster system is probably the best bang for the $ out there for LT1's,compared to the others,which on a stock motor your really just paying almost $600 more for the look,and corrosion resistance of the stainless ones,and personal sound preference.if the stock Y and resonator are still in good condition,I think just a pair of high flow cats($300) muffler eliminators,40 series flowmaster,or the dynomax's($200) will be cheaper,sound better,and give more performance than the other systems out there.would really like to see some more comparo's though.I like the sound of the eliminators,but you do lose a little bottom end throttle response,unlike the mufflers.
Last edited by vette&f-bod lover; Jun 28, 2005 at 09:39 PM.
Thread Starter
Burning Brakes
Joined: Jun 2005
Posts: 861
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From: Hyde Park NY
St. Jude Donor '05
thanks for all the input. Even if I get only a 5% hp improvement, with the super sound, it was worth the $$$. (of course I had to pay to have it installed (all thumbs here) so I paid a premium).
Drive on !!
Drive on !!
