Mom's Car Posted December 4, 2010 Share Posted December 4, 2010 Has anyone been to the track and done some back to back runs? Just curious to see how much hp loss there is. I have a 498 (624hp) going through a 2.5" flowmaster system to the bumper. .............thanks......Greg Quote Link to comment Share on other sites More sharing options...
502ci Posted December 4, 2010 Share Posted December 4, 2010 I've done it many times but I think every car is gonna respond different because of the diameter of the exhaust, muffler type, exhaust length, how much hp, etc.). I have a 3 1/2" system all the way to the back and have 3 1/2" electric cut-outs right behind the header. Mine was running the same open or closed with roughly 540hp...I've done hot laps alternating open and closed and they were the same. I do have 3 disk slip in muffler/silencers that slip into my exhaust tips that quiet my car down quite a bit, now those slowed me down almost 2 tenths. With 624hp you are putting out and a full length 2 1/2" system I would think you would see some benefit to cut-outs or open headers. Quote Link to comment Share on other sites More sharing options...
Mom's Car Posted December 4, 2010 Author Share Posted December 4, 2010 I've done it many times but I think every car is gonna respond different because of the diameter of the exhaust, muffler type, exhaust length, how much hp, etc.). I have a 3 1/2" system all the way to the back and have 3 1/2" electric cut-outs right behind the header. Mine was running the same open or closed with roughly 540hp...I've done hot laps alternating open and closed and they were the same. I do have 3 disk slip in muffler/silencers that slip into my exhaust tips that quiet my car down quite a bit, now those slowed me down almost 2 tenths. With 624hp you are putting out and a full length 2 1/2" system I would think you would see some benefit to cut-outs or open headers. I was contemplating the Torque Tech exhaust. I spoke to the guy and he said they were not making the 3.5" tailpipes as there was very little demand. I guess I could always use 3" tailpipes. I was just curious as to "real world" difference in performance as I regularly cruise with the car and the closest track is a million miles away. West Palm looks awfully good right about now. But I digress. I don't particularly like open exhaust and thought that the 3.5" would be the best of both worlds (As your test proves) Just trying to justify replacing a perfectly good exhaust.................thanks for the input.....Greg Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted December 4, 2010 Share Posted December 4, 2010 your car would surely benefit from a larger exhaust system Quote Link to comment Share on other sites More sharing options...
Mom's Car Posted December 4, 2010 Author Share Posted December 4, 2010 your car would surely benefit from a larger exhaust system Thanks..........and don't call me shirley Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted December 4, 2010 Share Posted December 4, 2010 My exhaust is a 3 inch x pipe with 3 inch cut outs it goes into reducer cones into 2 1/2 mufflers. Never ran it through the mufflers, no reason to since I have the cut outs. I have removed the X pipe and cutouts and it has run its best times without it. Not really had the time at the track to be putting the stuff on and off. Can't tell you horsepower loss, the best way to do that is with a chassis dyno. I would like to try some different length extension on my headers to see if that makes a difference. I like the cut outs they are fun on the street and at cruises but I think that at a certain level open exhaust is he way to go. Making 624 hp you should be at a level that open exhaust would be the way to go at the track. Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted December 4, 2010 Share Posted December 4, 2010 Making 624 hp you got to get it to a track! You have to be just spinning your wheels on the street. Quote Link to comment Share on other sites More sharing options...
Mom's Car Posted December 4, 2010 Author Share Posted December 4, 2010 My exhaust is a 3 inch x pipe with 3 inch cut outs it goes into reducer cones into 2 1/2 mufflers. Never ran it through the mufflers, no reason to since I have the cut outs. I have removed the X pipe and cutouts and it has run its best times without it. Not really had the time at the track to be putting the stuff on and off. Can't tell you horsepower loss, the best way to do that is with a chassis dyno. I would like to try some different length extension on my headers to see if that makes a difference. I like the cut outs they are fun on the street and at cruises but I think that at a certain level open exhaust is he way to go. Making 624 hp you should be at a level that open exhaust would be the way to go at the track. It sounds like I should just go with the 3.5" electric cut outs and call it a day. Any brand recommendations? Quote Link to comment Share on other sites More sharing options...
Mom's Car Posted December 4, 2010 Author Share Posted December 4, 2010 Making 624 hp you got to get it to a track! You have to be just spinning your wheels on the street. I did get to go in September. I just had the motor freshened up literally the week before and took it a little easy as to not grenade the thing before the ink was dry on the check. It ran a best of 11.94 at 116 with a 1.81 60'. Car hooked good but I was short shifting it. All was fine till the belt flew off pounding that imaginery gear between 3rd and 5th on a tremec. No one told me about that quirk in the tremec trans until after that happened. I had to stop running both the cars I brought since I only had one trailer..........bummer.... Quote Link to comment Share on other sites More sharing options...
502ci Posted December 4, 2010 Share Posted December 4, 2010 It sounds like I should just go with the 3.5" electric cut outs and call it a day. Any brand recommendations? Are you saying you are just gonna add the cut-outs and keep the rest of the exhaust...if so that's what I would do. What size are your header collectors, are they 3" or 3 1/2"? If they are not 3 1/2" you are gonna have to settle for 3" electric cut-outs or buy new headers. Quote Link to comment Share on other sites More sharing options...
Mom's Car Posted December 4, 2010 Author Share Posted December 4, 2010 Originally Posted By: Mom's Car It sounds like I should just go with the 3.5" electric cut outs and call it a day. Any brand recommendations? Are you saying you are just gonna add the cut-outs and keep the rest of the exhaust...if so that's what I would do. What size are your header collectors, are they 3" or 3 1/2"? If they are not 3 1/2" you are gonna have to settle for 3" electric cut-outs or buy new headers. Yes I have 3.5" collectors and yes I would just use the current system ............unless someone local wants to buy a perfectly good aluminized 2.5" flowmaster system.......then I would be forced to go to the 3.5" system. Anyone use torque tech? Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted December 4, 2010 Share Posted December 4, 2010 I have the 3 1/2" torque tech and love it! Quote Link to comment Share on other sites More sharing options...
Mom's Car Posted December 4, 2010 Author Share Posted December 4, 2010 I have the 3 1/2" torque tech and love it! I checked out your pics. Those 3.5" tailpipes look great. Too bad they are discontinued. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted December 4, 2010 Share Posted December 4, 2010 they discontinued them??? Quote Link to comment Share on other sites More sharing options...
Mom's Car Posted December 4, 2010 Author Share Posted December 4, 2010 they discontinued them??? I spoke the dude yesterday and he said it took 2 years to sell 25 sets so it wasn't worth getting them made anymore. Quote Link to comment Share on other sites More sharing options...
502ci Posted December 4, 2010 Share Posted December 4, 2010 I have Torque Tech as Sam(Bones) does also, actually quite a few people on the site have their systems. They are absolutely perfect (in my opinion) to get a whopping 3 1/2" of tubing all the way out the back. Kinda cool they don't make them any more making my system more rare... To be honest if I was to do it all over again I would do what you are doing right now with a large cut-out and down size to a small pipe...I would like to lower my rear even more but my large tubes are in the way. I went with Summit's brand cut-outs as they can be welded on or clamped on. You may have some fab work to do if you have reducer cones on your collectors, my exhaust tubing was already 3 1/2" pipe so I just cut a section out, I "band clamped" mine in. I'm not sure if they make ones that bolt right to the collector but that would be the way to go for you. I have "DMH" electric cut-outs that I got from Summit Racing but I know they don't carry them any more...the design was just like the "Race Ready Performance" ones. I have since bought "Quick Time Performance" ones for my Truck that works just as well. Quote Link to comment Share on other sites More sharing options...
TN454Monte Posted December 4, 2010 Share Posted December 4, 2010 No more Torque-Tech? Boooo! I was going to try to use them at some point too! Quote Link to comment Share on other sites More sharing options...
Mom's Car Posted December 4, 2010 Author Share Posted December 4, 2010 I have Torque Tech as Sam(Bones) does also, actually quite a few people on the site have their systems. They are absolutely perfect (in my opinion) to get a whopping 3 1/2" of tubing all the way out the back. Kinda cool they don't make them any more making my system more rare... To be honest if I was to do it all over again I would do what you are doing right now with a large cut-out and down size to a small pipe...I would like to lower my rear even more but my large tubes are in the way. I went with Summit's brand cut-outs as they can be welded on or clamped on. You may have some fab work to do if you have reducer cones on your collectors, my exhaust tubing was already 3 1/2" pipe so I just cut a section out, I "band clamped" mine in. I'm not sure if they make ones that bolt right to the collector but that would be the way to go for you. I have "DMH" electric cut-outs that I got from Summit Racing but I know they don't carry them any more...the design was just like the "Race Ready Performance" ones. I have since bought "Quick Time Performance" ones for my Truck that works just as well. Thanks for all the info. It always helps to find out what works and doesn't before you do it. So I guess from what you are saying, the tailpipes fit but they restrict the ride height of the rear? My car sits lower than yours so they might not fit anyway. Quote Link to comment Share on other sites More sharing options...
Mom's Car Posted December 4, 2010 Author Share Posted December 4, 2010 No more Torque-Tech? Boooo! I was going to try to use them at some point too! Torque Tech still has every thing but the 3.5" tailpipes. Quote Link to comment Share on other sites More sharing options...
Heckeng Posted December 4, 2010 Share Posted December 4, 2010 I have a 454 with a puny 450hp or so, and 3" exhaust with flowmaster 50 series mufflers and I picked up 0.10 by running open headers. I think you will pick up significantly at that power level and using 2.5" exhaust. Quote Link to comment Share on other sites More sharing options...
downset71 Posted December 4, 2010 Share Posted December 4, 2010 compression ratio is more important to gaining with open headers than actual H.P. level.... Quote Link to comment Share on other sites More sharing options...
CrazyDavey Posted December 4, 2010 Share Posted December 4, 2010 Greg my wife has run her Monte both closed and open but not on the same day. Her car is north of 600 and seems to like being open, there was almost a 2 tenths difference on those days. She has a 2 1/2 Flowmaster system with Super 40's and the small 1 3/4" headers. She ran an 11.66 open just putting it in drive. I have never a and b'd the Chevelle, it makes 654 and like Mike said when you get up as high as your car open is going to make a difference. Just personally speaking I don't like the sound of cut outs, I would rather run the car open or closed. I also have experimented with collector extensions and found that on my car a 10" extension seems to help my 60'...FWIW...Dave Quote Link to comment Share on other sites More sharing options...
Mom's Car Posted December 5, 2010 Author Share Posted December 5, 2010 Thanks for the feedback guys. It sounds like it's right around a 2 tenths and 30 hp loss. Quote Link to comment Share on other sites More sharing options...
Monteman1971 Posted December 5, 2010 Share Posted December 5, 2010 Hey Greg, I have 2 inch header pipes with 3 1/2 inch collectors and a 2 1/2 inch exhaust system with a cross over and the 2 1/2 electric cut out....they are more fun than sliced bread... This year at Super Chevy I ran passes with them opened and closed and gained 2 tenths with them open. It was a brutal hot day with temps over 100 degrees so the car wasn't running it's numbers that day but but it was consistent all day. I have the "Race Ready Performance" brand. Their the only ones guaranteed for life. Eventually I'd like to go with a 3 inch exhaust system but still keep my current cut outs. Steve Quote Link to comment Share on other sites More sharing options...
Chevyss Posted December 5, 2010 Share Posted December 5, 2010 Love ths sound of the cutouts, but the 3" torque tech exhaust sounds good too. Guess one of these years I'll be able to get some numbers at the track. Quote Link to comment Share on other sites More sharing options...
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