LuLu Posted January 8, 2008 Report Share Posted January 8, 2008 The thing about building a street/track performance car, is how to get it done. We here have been real good at dicing out which supercharger is best, but, we seem to stop there. There's a lot more to it, but you have to take one step at a time. Now that you have your supercharger of personal choice, and the boost and tune dialed in, what's next? There's a lot of performance lost in the exhaust system and I see very little 411 exchanged about recovering this performance. Yes, there have been a few threads about sound, but sound doesn't mean power. Exhaust is 1/4 the power equasion, gents, 25 percent of your performance depends on how you shed exhaust gas. I don't think anyone will disagree that "headers" are better than the OEM manifolds, but there are circumstances where they are not. I won't get into that right now. But...What's next down the exhaust line? Cats. Catalytic converters. High flow cats can restore/recover a lot of power to the small CID SGT engine. You cannot (or shouldn't) remove them, they are protected by federal law. Like seatbelts, everyone has to have them, and has to use them. But, you can replace them with equal (if not improved) performance. Let's start here? http://www.randomtechnology.com/ I have used them in the past. I passed all emissions testing, and I found another 15 RWHP/10 RWQT after my install on a 4.6L-4V Marauder. It may seem "nickle and dime" improvements, but add up the nickles, and you have a buck. Some of y'all are veryveryclose to the 500 HP mark, and wonder why you can't cross that line? Cats. Happy mororting, gents. Link to comment Share on other sites More sharing options...
hypersurf1 Posted January 8, 2008 Report Share Posted January 8, 2008 LuLu, From what I have read ford has left very little on the table for performance on our 3v aside from power adders. My understanding is headers, hi flo cats, delete plates, throttle bodies, etc. offer very small performance gains when compared to cranking up the boost. As you very well know the weakest link is our short blocks. Once I address that deficiency I plan to start cranking the boost up. I have read of many people running alot of boost and HP on our cars without touching the heads, cams, exhaust, etc. For a N/A car I think the only resort is alot of these small improvements compounded into a respectable increase. For us FI guys we can just crank up the boost and not add more parts aside from fuel systems and the associated driveline parts. Link to comment Share on other sites More sharing options...
LuLu Posted January 8, 2008 Author Report Share Posted January 8, 2008 LuLu, From what I have read ford has left very little on the table for performance on our 3v aside from power adders. My understanding is headers, hi flo cats, delete plates, throttle bodies, etc. offer very small performance gains when compared to cranking up the boost. As you very well know the weakest link is our short blocks. Once I address that deficiency I plan to start cranking the boost up. I have read of many people running alot of boost and HP on our cars without touching the heads, cams, exhaust, etc. For a N/A car I think the only resort is alot of these small improvements compounded into a respectable increase. For us FI guys we can just crank up the boost and not add more parts aside from fuel systems and the associated driveline parts. I cannot disagree with your thoughts, Hyper, the SGT exhaust is very refined, and there is little to collect together after an SGT upgrade. But like I said, it's all "nickles and dimes", and every nickle counts in some situations. I've seen comments here where owners have opened up the exhaust to 3.0 ID, and I've wondered how that has any effect/improvement on performance. In my experience, it won't offer any improvements, may cost some power in some situations. Likewise, the SPP catalogue offers JBA headers for the 3V on a Mustang frame, as well as X-pipe upgrades and while I think we have the best possible combination for a stock 3V going on already, I wonder. But, as some of have shown, it's all about chasing the HP and TQ, and I would hate to see anyone spend any unnecessary money without knowing where they are going. You should know, once you're pumping 14-16 PSI of boost, the exhaust has got to go somewhere, right? But, where? How? Let's talk about this? Especially this week when our major power posters will be out of town? Got to have something to chat about, eh? Link to comment Share on other sites More sharing options...
ilmor Posted January 8, 2008 Report Share Posted January 8, 2008 I don't know exactly where I saw them, but there are both long-tube headers and exhaust-piping-just-beyond-headers (whatever you call those pieces) which are available with hi-flow cats, in addition to random tech cats. Last time I checked ( a month ago), Random did not make cats for our model year Mustang yet. I have to believe that there are some decent performance gaines to be had w/ the hi-flow cats. I was thinking something like this would be interesting (pure guess at some numbers); Brenspeed Tune - 6 hp Hi-Flow cats - 5 hp(?) Bullitt CAI box - 2 hp(?) Steeda intake tube - 2 hp(?) U/D pullies - 10 hp Royal Purple - 2 hp(?) Total added HP - 27 hp + 319 stock hp = 346 hp Do you think all this is possible? Might be something I'll check out a little in my post-warranty years. Link to comment Share on other sites More sharing options...
stump_breaker Posted January 8, 2008 Report Share Posted January 8, 2008 I really believe before you go upgrading the intake and exhaust - since what we have flows very well now - if you want to keep your car N/A the next best mod would be higher flowing heads and then start upgrading headers, cats and etc. Someone posted awhile back and did a dyno run after some very expensive exhaust mods and the gain was something like 12HP. IMO, $1000 to $1200 spent is not worth 12HP. For ~$2000 a set of heads can add right at ~30 HP and the additional upgrades wold be better utilized. Link to comment Share on other sites More sharing options...
mrhugger Posted January 8, 2008 Report Share Posted January 8, 2008 Maybe a stupid question but does anyone know the specs on the sgt system. Brand name, opening size etc. Thanx Steve Maybe a stupid question but does anyone know the specs on the sgt system. Brand name, opening size etc. Thanx Steve Link to comment Share on other sites More sharing options...
SGT2666 Posted January 8, 2008 Report Share Posted January 8, 2008 Everything I've seen says that the ROI on exhaust is pretty weak maybe 6 hp. Something I don't fully understand is that if you free up your exhaust flow enough it affects boost levels negatively. They say you may have to change pully size to maintain boost. Link to comment Share on other sites More sharing options...
ilmor Posted January 8, 2008 Report Share Posted January 8, 2008 I really believe before you go upgrading the intake and exhaust - since what we have flows very well now - if you want to keep your car N/A the next best mod would be higher flowing heads and then start upgrading headers, cats and etc. Someone posted awhile back and did a dyno run after some very expensive exhaust mods and the gain was something like 12HP. IMO, $1000 to $1200 spent is not worth 12HP. For ~$2000 a set of heads can add right at ~30 HP and the additional upgrades wold be better utilized. Problem is not all of us can afford a big, high cost upgrade all at once, so these little crumbs we get like cats or CAI's are very meaningful! Anyway, these hi-flow heads are not emissions-legal, are they? Everything I've seen says that the ROI on exhaust is pretty weak maybe 6 hp. Something I don't fully understand is that if you free up your exhaust flow enough it affects boost levels negatively. They say you may have to change pully size to maintain boost. Boost? I don't got no boost! Link to comment Share on other sites More sharing options...
SGT2666 Posted January 8, 2008 Report Share Posted January 8, 2008 Problem is not all of us can afford a big, high cost upgrade all at once, so these little crumbs we get like cats or CAI's are very meaningful! Anyway, these hi-flow heads are not emissions-legal, are they? Boost? I don't got no boost! You don't need boost to go the speed limit :rolleyes: Link to comment Share on other sites More sharing options...
DreamRide Posted January 8, 2008 Report Share Posted January 8, 2008 You don't need boost to go the speed limit :rolleyes: I dont think he even does the speed limit...... Link to comment Share on other sites More sharing options...
LuLu Posted January 8, 2008 Author Report Share Posted January 8, 2008 Though there are no moving parts, the exhaust system is a very dynamic component of building power, which is to say it's an active component. A few years back, I replaced the OEM exhaust manifolds on my 4V Marauder with OEM manifolds from the '03-'04 4V Cobra. They are port-matched to the D shaped 4V exhaust ports, while the OEM Marauder manifold is not. Using 2.50 OD exhaust pipe, I added Magnaflow high flow cats, (two replacing the four in the OEM setup) followed by a Magnaflow X pipe replacing the OEM H pipe. More 2.50 OD exhaust pipe into Magnaflow turbo mufflers. Out of the muffler, I retained the OEM 2.25 OD tailpipes because they were mandrel bent, and I was concerned about clearance issues. Besides, by the time exhaust gases hit the smaller OD tailpipes, they have cooled and won't choke up from the smaller OD. The Marauder also had "resonator" tips, a last minute design change to lower NVH, so, I removed the resonatior tip and replaced them with wide open 3.5" OD polished tips. I loved the sound, so did many others. We did back to back before/after dyno testing which showed 30 RWHP and 30 RWTQ gains. We didn't even unstrap the car from the above ground DynoJet, so, it was as legit and carefully planned as we could get. Cost of parts: 1000.00 Labor: DIY = free? Dyno charges: 200.00 Very reasonable bang for the buck. Some time later, Kook's came out with a mid-length header and other Marauder owners reported higher gains, as much as 50 RWHP, and 35 RWTQ. All dyno supported. I wouldn't expect these results from an SGT, simply due to what comes with the car. Stoock Mustang GT? Maybe? IMHO, the right set of headers and high flow cats will add some power, but changing anything else in the SGT system is prolly not worth it. Just my .02C gents, carry on... Link to comment Share on other sites More sharing options...
SGT2666 Posted January 8, 2008 Report Share Posted January 8, 2008 We've got the mufflers and X pipe, do we have high flow cats? I would think modern exhaust manifold design is pretty good these days but you never know. My bikes respond pretty dramatically to letting them breath. Link to comment Share on other sites More sharing options...
LuLu Posted January 8, 2008 Author Report Share Posted January 8, 2008 We've got the mufflers and X pipe, do we have high flow cats? I would think modern exhaust manifold design is pretty good these days but you never know. My bikes respond pretty dramatically to letting them breath. I have looked over the SGT exhaust system on my SGT several times, and while I can't say for sure, the cats appear to be standard FMC fare. Moreover, I haven't found anything in print anywhere that describes a change/upgrade from the SGT treatment. Honestly, this is a question for SAI, maybe someone will drop by? Headers will always improve over manifolds, but you have to find the right design. Primary and collector diameters are important, too large and too long can cost power. But, they usually weigh 1/2 of the cast iron manifold, and this is good. And, they carry away heat from the engine/combustion chamber, this is a second good. I agree with you, improved exhaust flow is the goal, but there is a lot of junk out there too. Bigger is not always better. Link to comment Share on other sites More sharing options...
ilmor Posted January 9, 2008 Report Share Posted January 9, 2008 I dont think he even does the speed limit...... Hey!! I do the speed limit!! I do, really!! Link to comment Share on other sites More sharing options...
mickey mustang Posted January 9, 2008 Report Share Posted January 9, 2008 I cannot disagree with your thoughts, Hyper, the SGT exhaust is very refined, and there is little to collect together after an SGT upgrade. But like I said, it's all "nickles and dimes", and every nickle counts in some situations. I've seen comments here where owners have opened up the exhaust to 3.0 ID, and I've wondered how that has any effect/improvement on performance. In my experience, it won't offer any improvements, may cost some power in some situations. Likewise, the SPP catalogue offers JBA headers for the 3V on a Mustang frame, as well as X-pipe upgrades and while I think we have the best possible combination for a stock 3V going on already, I wonder. But, as some of have shown, it's all about chasing the HP and TQ, and I would hate to see anyone spend any unnecessary money without knowing where they are going. You should know, once you're pumping 14-16 PSI of boost, the exhaust has got to go somewhere, right? But, where? How? Let's talk about this? Especially this week when our major power posters will be out of town? Got to have something to chat about, eh? I'm not a mechanic here, but I try to read as much as possible regarding upgrades to the Mustang platform, and one thing that always seems to play a part in an upgrade is safety....safety regarding detonation in our stock 4.6 3v's Seems as though detonation can make scrap our of our engines real fast if we're not careful with engine mods. That being said, and in the essence of safely creating hp, I see no mention of a simple upgrade without all the hassels..........install a one piece aluminum driveshaft.....lower rotating mass relates to nice hp gains. I did this with a brenspeed tune on a s.c. sgt and I couldn't be happier. Don't think I would ever use more hp than I getting from this mod. Link to comment Share on other sites More sharing options...
SGT2666 Posted January 9, 2008 Report Share Posted January 9, 2008 I'm not a mechanic here, but I try to read as much as possible regarding upgrades to the Mustang platform, and one thing that always seems to play a part in an upgrade is safety....safety regarding detonation in our stock 4.6 3v's Seems as though detonation can make scrap our of our engines real fast if we're not careful with engine mods. That being said, and in the essence of safely creating hp, I see no mention of a simple upgrade without all the hassels..........install a one piece aluminum driveshaft.....lower rotating mass relates to nice hp gains. I did this with a brenspeed tune on a s.c. sgt and I couldn't be happier. Don't think I would ever use more hp than I getting from this mod. I'm looking at the Steeda aluminum shaft, they taper the 4" down to 3.5" and eliminate the clearance issues. Link to comment Share on other sites More sharing options...
DreamRide Posted January 9, 2008 Report Share Posted January 9, 2008 Hey!! I do the speed limit!! I do, really!! i know you do ilmor................. Link to comment Share on other sites More sharing options...
LuLu Posted January 9, 2008 Author Report Share Posted January 9, 2008 I'm not a mechanic here, but I try to read as much as possible regarding upgrades to the Mustang platform, and one thing that always seems to play a part in an upgrade is safety....safety regarding detonation in our stock 4.6 3v's Seems as though detonation can make scrap our of our engines real fast if we're not careful with engine mods. That being said, and in the essence of safely creating hp, I see no mention of a simple upgrade without all the hassels..........install a one piece aluminum driveshaft.....lower rotating mass relates to nice hp gains. I did this with a brenspeed tune on a s.c. sgt and I couldn't be happier. Don't think I would ever use more hp than I getting from this mod. I agree with the one-piece driveshaft being more durable and the better way to go, but it's cost causes me to deliberte the need. If you are not into some type of high performance driving on a regular basis, the cost is not justified. If you're hitting the track (1/4 mile or road course) twice a month, get one. If you are just enjoying on-ramp pulls through the gears, don't spend the money. There's nothing wrong with the factory setup, other than it's two piece design, which doubles your potential weak spots, the U-joints. Oh, and it's a tad lighter, yes, but nominal power gains at best. I've been speaking in terms of "nickles and dimes" in power adding up, and this would be a "penny" power upgrade. If you decide you want one anyway, don't forget the driveshaft loop at the forward U-joint. May be required by the rules of some race associations under 12.00 ET. But, so is a firesuit and helmet. Link to comment Share on other sites More sharing options...
fatboy_merged Posted January 10, 2008 Report Share Posted January 10, 2008 whats inside cat converters anyway? is it a filter? or is it some kind of a nest of hairy steel wool or what? or is it simply just a glorified muffler dubbed by EPA as "a smog reducer"? :huh: Link to comment Share on other sites More sharing options...
LuLu Posted January 10, 2008 Author Report Share Posted January 10, 2008 whats inside cat converters anyway? is it a filter? or is it some kind of a nest of hairy steel wool or what? or is it simply just a glorified muffler dubbed by EPA as "a smog reducer"? :huh: Well...There have been a few changes over the years. In the late '70, GM was using a catalyst content that swelled up after X number of miles from cheap fuels still on the market, and this totally blocked the exhaust system and required replacement. Things are better today, peek here for more 411? http://en.wikipedia.org/wiki/Catalytic_converter Link to comment Share on other sites More sharing options...
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