| z3coupe | 05-31-2002 12:28 AM |
STX Legal exhaust testing . . .
I am currently working with Ian at PDE to try and design an exhaust system legal for STX. For once WE have someone willing to listen to us cone-manglers instead of the show or drag crowds! Add to that, that he too is a tourque lover, and you'll see we are looking to IMPROVE the lack of lowned on our beasts.
We started phase 1, which was a complete cat-LESS car. The test at the last AutoX was a success! There IS now lowned grunt with the PDE cat-less system. Not perfect, but way more than stock and enough to keep you from wanting to jam it into 1st gear. I ran with the stock airbox on, and it was great. But afterwards (cause Ian wanted results with the stock airbox on), I reinstalled my MRT POD filter, and the car was even better!!!!! Throttle response and power are wonderful. And get this, . . . . . not one CEL!!!!!!!
Now, it has gotten a bit loud, so when back on the street I run about 18 discs on my Supertrapp. I only notice a slight high end loss, but the low end is still there, might even be a bit better with having some back pressure - which would be great for our next phase, installing a free flow cat (and in different locations), and perhaps making the rest of the system 3" as well. But at the moment, we are also trying to see how much of the stock parts we can keep on as well, to keep the costs down.
At the AutoX (was in SD at the "Q"), everyone who heard the car absolutely loved the sound of it. One i-Clubber remarked that it sounded exactly like the rally cars! Even pops a bit when up-shifting, and pops/gurgles on decel. And even with no discs, and no cats, I had no problems with the SD noise limits either.
So the setup at the moment, is the MRT POD filter, PDE U/P, PDE 3" D/P with bell mouth and no cats, with a reducer on the end to make it fit on the rest of the stock piping, and ending in a 4"X17" Supertrapp. I for once was very close to the STS 1st place guy, and IF I had gotten there early enough to have walked the course (it was an unusual one to say the least!), and got some of the understeer removed (working on that too), for once that car could have done great. Oh, but I was not running in STX (SD don't have it anyway), I ran in SM.
We started phase 1, which was a complete cat-LESS car. The test at the last AutoX was a success! There IS now lowned grunt with the PDE cat-less system. Not perfect, but way more than stock and enough to keep you from wanting to jam it into 1st gear. I ran with the stock airbox on, and it was great. But afterwards (cause Ian wanted results with the stock airbox on), I reinstalled my MRT POD filter, and the car was even better!!!!! Throttle response and power are wonderful. And get this, . . . . . not one CEL!!!!!!!
Now, it has gotten a bit loud, so when back on the street I run about 18 discs on my Supertrapp. I only notice a slight high end loss, but the low end is still there, might even be a bit better with having some back pressure - which would be great for our next phase, installing a free flow cat (and in different locations), and perhaps making the rest of the system 3" as well. But at the moment, we are also trying to see how much of the stock parts we can keep on as well, to keep the costs down.
At the AutoX (was in SD at the "Q"), everyone who heard the car absolutely loved the sound of it. One i-Clubber remarked that it sounded exactly like the rally cars! Even pops a bit when up-shifting, and pops/gurgles on decel. And even with no discs, and no cats, I had no problems with the SD noise limits either.
So the setup at the moment, is the MRT POD filter, PDE U/P, PDE 3" D/P with bell mouth and no cats, with a reducer on the end to make it fit on the rest of the stock piping, and ending in a 4"X17" Supertrapp. I for once was very close to the STS 1st place guy, and IF I had gotten there early enough to have walked the course (it was an unusual one to say the least!), and got some of the understeer removed (working on that too), for once that car could have done great. Oh, but I was not running in STX (SD don't have it anyway), I ran in SM.
| TheWRX | 05-31-2002 08:12 AM |
I'm curious why you believe you need a spcifically designed exhaust for STX. Do the commonly available options (I'm mainly thinking about TurboXS) not meet the rules about the placement of the high-flow cat? Or do you just think that they wouldn't give you the kind of performance you're looking for?
| Rebellion | 05-31-2002 09:06 AM |
he's griping because with most turbobacks you lose low end performance.
| TheWRX | 05-31-2002 10:00 AM |
Looking at [URL=http://www.turboxs.com/turboxs_2002_wrx_stage_2_torque_.htm]this dyno plot[/URL] comparing TurboXS Stage 1 vs. Stage 2 (the difference between the two being the turbo-back and a reprogrammed Unichip), I don't see a loss anywhere in the powerband. Granted, the biggest gains start above 3000 rpm, but the torque is higher all the way.
| elgorey | 05-31-2002 10:14 AM |
[QUOTE]I for once was very close to the STS 1st place guy,[/QUOTE]
well assuming that your local STS guys are good then that is very impressive! At the national events STX is usually around 1, sometimes 2 seconds slower than STS.
I have to disagree about the current exhaust offerings robbing low end power though. Since our cars are turbocharged, anything that spools the turbo quicker is going to give us the most low end power.
[QUOTE]and got some of the understeer removed [/QUOTE]
youre having problems with understeer? I actually had to lower rear tire pressures to keep my backend in line last weekend at the pro. and all i have is cusco front and rear swaybars. (no coilovers...yet)
[QUOTE]Looking at this dyno plot comparing TurboXS Stage 1 vs. Stage 2 [/QUOTE]
thats not a very good comparison since in STX boost cannot be altered and therefore txs unichip is not legal
well assuming that your local STS guys are good then that is very impressive! At the national events STX is usually around 1, sometimes 2 seconds slower than STS.
I have to disagree about the current exhaust offerings robbing low end power though. Since our cars are turbocharged, anything that spools the turbo quicker is going to give us the most low end power.
[QUOTE]and got some of the understeer removed [/QUOTE]
youre having problems with understeer? I actually had to lower rear tire pressures to keep my backend in line last weekend at the pro. and all i have is cusco front and rear swaybars. (no coilovers...yet)
[QUOTE]Looking at this dyno plot comparing TurboXS Stage 1 vs. Stage 2 [/QUOTE]
thats not a very good comparison since in STX boost cannot be altered and therefore txs unichip is not legal
| MrBrian | 05-31-2002 12:16 PM |
will stx be at nationals?
i heard it wasnt.
i heard it wasnt.
| travmn | 05-31-2002 12:34 PM |
any chance of a dyno chart with your setup vs. your stock setup?
| 2QUICK4U | 05-31-2002 01:27 PM |
Yah what Brian said, is STX going to be run at Nationals? And if I ran in ESP at one of the Tour events, can I run STX at Nationals?
As far as I know other Turboback systems already on the market (like MRT which I have) are perfectly legal now for STX. Please correct me if I'm wrong.
As far as I know other Turboback systems already on the market (like MRT which I have) are perfectly legal now for STX. Please correct me if I'm wrong.
| elgorey | 05-31-2002 01:38 PM |
IIRC, STX will be a "provisional" class at nationals. There will be a class, but no trophies. (i think thats how it works)
any turbo back exhaust with a cat is legal for STX, Rocky is just working to develop an autoX tuned system that will maximize low end torque.
any turbo back exhaust with a cat is legal for STX, Rocky is just working to develop an autoX tuned system that will maximize low end torque.
| z3coupe | 05-31-2002 08:19 PM |
[QUOTE]any turbo back exhaust with a cat is legal for STX, Rocky is just working to develop an autoX tuned system that will maximize low end torque.[/QUOTE]
EXACTLY! Almost all the systems out there now is mainly for the show or drag guys. Folks with no rules restricting mods (except pocket book), running boost, FMIC, BOV's, etc . . . . and all looking for that magic 1/4 mile time. What we need in AutoX, and is killing us, is lowend torque! Going into 1st is not an option, unless you want to keep replacing syncros. Why do you think the RS is killing many of us? Cause its got the lowend grunt we DON'T.
So Ian and I are working on putting together a D/P system (the U/P is fine no matter who's) and placing as free a flowing cat as we can (and keeping the price affordable) in different locations to find that sweet spot. AND, we are also trying to make it where you either could get a complete package, or be able to make it modular so that you could bolt it to some of the stock parts. So, it will be STX legal when we get done with this.
As for dyno charts, . . . . we might get to that later. But also remember that a dyno is only static - sitting still, as well as in 4th or 5th gear. In an AutoX, we are taking a slow turn in 2nd gear under extremely stressfull conditions, with many other factors inviolved (as in LFB, blipping throttle to try to keep boost up, etc). So most of the testing will be butt dyno live out on the course.
[QUOTE]I have to disagree about the current exhaust offerings robbing low end power though. Since our cars are turbocharged, anything that spools the turbo quicker is going to give us the most low end power.[/QUOTE]
Again, as I stated above, most systems were never designed for AutoX and lowend. Its either for show, drags, or bragging rights. Nor was any of it designed to fit the rules of allowable mods in the STX class, or the ability to be added to some of the stock parts left on the car. So there is a difference. Many are more concerned with the looks (coffee can) or the sound (loud = faster?????) which also can be designed in to make it sound like any car out there. With the right harmonics, you could make a Miata sound like a V8. Take as an example, when Mazda was designing the Miata, their engineers went all over the world taping sports car exhausts. they designed their system to sound like the best one they heard.
[QUOTE]youre having problems with understeer? I actually had to lower rear tire pressures to keep my backend in line last weekend at the pro. and all i have is cusco front and rear swaybars. (no coilovers...yet)[/QUOTE]
I have a different setup. I have Cusco Zero2 coilovers, MRT rear bar, and a prototype RS*R adjustable front bar (has a box with a 12 adj dial on it). So things are not the same, and I am still tweaking it.
EXACTLY! Almost all the systems out there now is mainly for the show or drag guys. Folks with no rules restricting mods (except pocket book), running boost, FMIC, BOV's, etc . . . . and all looking for that magic 1/4 mile time. What we need in AutoX, and is killing us, is lowend torque! Going into 1st is not an option, unless you want to keep replacing syncros. Why do you think the RS is killing many of us? Cause its got the lowend grunt we DON'T.
So Ian and I are working on putting together a D/P system (the U/P is fine no matter who's) and placing as free a flowing cat as we can (and keeping the price affordable) in different locations to find that sweet spot. AND, we are also trying to make it where you either could get a complete package, or be able to make it modular so that you could bolt it to some of the stock parts. So, it will be STX legal when we get done with this.
As for dyno charts, . . . . we might get to that later. But also remember that a dyno is only static - sitting still, as well as in 4th or 5th gear. In an AutoX, we are taking a slow turn in 2nd gear under extremely stressfull conditions, with many other factors inviolved (as in LFB, blipping throttle to try to keep boost up, etc). So most of the testing will be butt dyno live out on the course.
[QUOTE]I have to disagree about the current exhaust offerings robbing low end power though. Since our cars are turbocharged, anything that spools the turbo quicker is going to give us the most low end power.[/QUOTE]
Again, as I stated above, most systems were never designed for AutoX and lowend. Its either for show, drags, or bragging rights. Nor was any of it designed to fit the rules of allowable mods in the STX class, or the ability to be added to some of the stock parts left on the car. So there is a difference. Many are more concerned with the looks (coffee can) or the sound (loud = faster?????) which also can be designed in to make it sound like any car out there. With the right harmonics, you could make a Miata sound like a V8. Take as an example, when Mazda was designing the Miata, their engineers went all over the world taping sports car exhausts. they designed their system to sound like the best one they heard.
[QUOTE]youre having problems with understeer? I actually had to lower rear tire pressures to keep my backend in line last weekend at the pro. and all i have is cusco front and rear swaybars. (no coilovers...yet)[/QUOTE]
I have a different setup. I have Cusco Zero2 coilovers, MRT rear bar, and a prototype RS*R adjustable front bar (has a box with a 12 adj dial on it). So things are not the same, and I am still tweaking it.
| MrBrian | 05-31-2002 11:06 PM |
if stx wont be a national autox event why bother? just make a nice turboback(striaght pipe and high flow cat) in single tip and dual tip. most exhaust out right now supposedly only differentiate about 2-3awhp(shiv's scc article). thats nothing because cars arent exact. i will be at autox nationals and i have the m2 dual tip with high flow cat. i know and can tell this exhaust isnt the most effecient, but its my daily driver. also remember many of the scoobie owners like quiet cars :)
| 2QUICK4U | 06-01-2002 12:51 AM |
if it's any indication, the entry form for the National Championship doesn't even show STX in any of the run groups. I was hoping to change from ESP to STX, but so much for that idea.:(
| z3coupe | 06-01-2002 02:02 AM |
[QUOTE]if stx wont be a national autox event why bother?[/QUOTE]
Then why did anyone bother with STS or SM??? You seem to have doomed STX before it even had a chance! Well, STS and SM were not much in their first years either. But look at them now . . . sometimes the single largest class in many local events.
And as for STX not being listed, this was mentioned earlier
[QUOTE]IIRC, STX will be a "provisional" class at nationals. There will be a class, but no trophies. (i think thats how it works)[/QUOTE]
But if everyone keeps dooming it, or say [QUOTE]I was hoping to change from ESP to STX, but so much for that idea.[/QUOTE] then no one will enter it and thus kill it themselves.
Then why did anyone bother with STS or SM??? You seem to have doomed STX before it even had a chance! Well, STS and SM were not much in their first years either. But look at them now . . . sometimes the single largest class in many local events.
And as for STX not being listed, this was mentioned earlier
[QUOTE]IIRC, STX will be a "provisional" class at nationals. There will be a class, but no trophies. (i think thats how it works)[/QUOTE]
But if everyone keeps dooming it, or say [QUOTE]I was hoping to change from ESP to STX, but so much for that idea.[/QUOTE] then no one will enter it and thus kill it themselves.
| Orion | 06-01-2002 10:31 AM |
I'm still trying to com up with a plan to head to Nats. I'd be all over an "STX Tuned" Turboback.
Despite the consensus, I think STX has a great chance. If I do plan on going to Topeka, I will enter in STX whether it's provisional or not!
Despite the consensus, I think STX has a great chance. If I do plan on going to Topeka, I will enter in STX whether it's provisional or not!
| TampaWRX | 06-01-2002 12:40 PM |
I think a lot of people will be interested in this exhaust system, z3. Keep us posted! As for an STX class...how many classes does the SCCA run now!?!?! :eek: I guess one more wouldn't hurt. :D
| ChrisW | 06-01-2002 12:44 PM |
z3coupe,
you should try looking at the Stromung and Scoobysports exhaust systems first.
[URL=http://www.rallyperformance.com/engine.htm#ScoobySport%20Exhaust]scoobysport[/URL]
[URL=http://www.stromung.com/subaru/subaru1.htm]stromung[/URL]
you should try looking at the Stromung and Scoobysports exhaust systems first.
[URL=http://www.rallyperformance.com/engine.htm#ScoobySport%20Exhaust]scoobysport[/URL]
[URL=http://www.stromung.com/subaru/subaru1.htm]stromung[/URL]
| z3coupe | 06-01-2002 02:36 PM |
[QUOTE]you should try looking at the Stromung and Scoobysports exhaust systems first.[/QUOTE]
Well Chris, I did go to see Scott at Stromung awhile back when we still had to have all the cats on per the OLD rules, as he is local. He was going to work with me to develop a system. His current (at that time) D/P was cat-less and had the stock style mouth with the plate against the wastegate. I tried to convince him we needed a bell mouth or separate chambers. He was interested in working with me. Then THAT was the last I ever heard from him for months! Never answered his phone, never returned calls from VM I left, not even E-Mails. Sorry, but not interested in his stuff anymore.
ScoobySport looked interesting, but back when we still needed all the cats in place (but could be substituted with a free flow), SS was ungodly with their prices. Fair they might have been, but $600 - $700 (depending on free flow or race cat) for a D/P was more than I could afford!
Then suddenly one day, from my posts, I get a mail from Ian at PDE. HE was interested in working with me, and he also loves torque! As I already had his U/P and like it, the rest is what you are reading now. Plus he too is local. Now again, all the other systems out there are "in general" systems. We are working on a specific goal - AutoX. Not drags, not show, not sound, but AutoX - and specifically towards the STX rules. So this is going to work with the stock boost, many of the stock parts, and even stock airbox if needed (or wanted still on). As I said, we will get it eventually on a dyno, but right now we prefer feeling it in actual use under those conditions. And so far it feels great! And I am even finding that maybe SOME backpressure might be good for lowned, cause as I run with 18 discs on my Supertrapp for street use, it seems to be quite peppy! Might be loosing a bit on the high side, but the bottom sure feels good!
Now, what might be something to try later, instead of a dyno, would be timing some rolling 25 (or 30) - 55mph runs. This would be the typical speeds coming out of a tight turn in 2nd gear, and get up to speed before the next turn. I used to do this years ago with a shop I worked with on my old 79 ASP RX7. Learned a lot that way! And that car was a legend in the MidWest back in the old days. Never got to the Nationals, but was region champ 4 years in a row, won every street GP we had (turned into a 3 city series), and never lost a time trial at Balckhawk Farms, Road America, or Grattan. :)
Well Chris, I did go to see Scott at Stromung awhile back when we still had to have all the cats on per the OLD rules, as he is local. He was going to work with me to develop a system. His current (at that time) D/P was cat-less and had the stock style mouth with the plate against the wastegate. I tried to convince him we needed a bell mouth or separate chambers. He was interested in working with me. Then THAT was the last I ever heard from him for months! Never answered his phone, never returned calls from VM I left, not even E-Mails. Sorry, but not interested in his stuff anymore.
ScoobySport looked interesting, but back when we still needed all the cats in place (but could be substituted with a free flow), SS was ungodly with their prices. Fair they might have been, but $600 - $700 (depending on free flow or race cat) for a D/P was more than I could afford!
Then suddenly one day, from my posts, I get a mail from Ian at PDE. HE was interested in working with me, and he also loves torque! As I already had his U/P and like it, the rest is what you are reading now. Plus he too is local. Now again, all the other systems out there are "in general" systems. We are working on a specific goal - AutoX. Not drags, not show, not sound, but AutoX - and specifically towards the STX rules. So this is going to work with the stock boost, many of the stock parts, and even stock airbox if needed (or wanted still on). As I said, we will get it eventually on a dyno, but right now we prefer feeling it in actual use under those conditions. And so far it feels great! And I am even finding that maybe SOME backpressure might be good for lowned, cause as I run with 18 discs on my Supertrapp for street use, it seems to be quite peppy! Might be loosing a bit on the high side, but the bottom sure feels good!
Now, what might be something to try later, instead of a dyno, would be timing some rolling 25 (or 30) - 55mph runs. This would be the typical speeds coming out of a tight turn in 2nd gear, and get up to speed before the next turn. I used to do this years ago with a shop I worked with on my old 79 ASP RX7. Learned a lot that way! And that car was a legend in the MidWest back in the old days. Never got to the Nationals, but was region champ 4 years in a row, won every street GP we had (turned into a 3 city series), and never lost a time trial at Balckhawk Farms, Road America, or Grattan. :)
| Orion | 06-03-2002 10:01 AM |
keepin' it alive.;)
if Ian needs a 2nd opinion on testing, make sure to drop me a line!
if Ian needs a 2nd opinion on testing, make sure to drop me a line!
| KC | 06-03-2002 10:58 AM |
Or a 3rd here. ;)
My problem isn't really with the power or torque that the car produces. Will they work with the solo auto-xer with something that will help the car pass THROUGH cones? That's my biggest downfall. :D
(I barely hit another cone... reported "By an inch or less" and because of that came in 2nd in STX at the Tour. Doh!)
--KC
My problem isn't really with the power or torque that the car produces. Will they work with the solo auto-xer with something that will help the car pass THROUGH cones? That's my biggest downfall. :D
(I barely hit another cone... reported "By an inch or less" and because of that came in 2nd in STX at the Tour. Doh!)
--KC
| Willman67 | 06-03-2002 11:37 AM |
I'm in too
I'm definately ready for a system that will be high flow and STX legal. any estimates on ready date? This also might fit the market niche of highest performance system while still being tailpipe test legal.
One more thing, if you could make sure that the downpipe has the same connection to the rear section as the factory downpipe than many aftermarket cat backs will work (I have the Borla).
Wm
One more thing, if you could make sure that the downpipe has the same connection to the rear section as the factory downpipe than many aftermarket cat backs will work (I have the Borla).
Wm
| z3coupe | 06-03-2002 12:24 PM |
The D/P is 3", but he has a reducer if needed to allow it to fit the stock pipes the rest of the way back.
As far as when? Can't say for sure. He is an extremely busy guy, and we have to do this when we both can get together at the same time (I got a job too ha ha). I am waiting now for him to get a cat back on my car for the AutoX this coming weekend.
As far as when? Can't say for sure. He is an extremely busy guy, and we have to do this when we both can get together at the same time (I got a job too ha ha). I am waiting now for him to get a cat back on my car for the AutoX this coming weekend.
| Orion | 06-03-2002 03:59 PM |
I think what everyone is trying to say is that ther WILL be a market for an AutoX tuned Turbo-back, although obviously it won't be as big as the normal market.
I'm still running stock everything except for my muffler because I have yet to see anything that really impresses me for AutoX type applications. If PDE could make one that caters to us, I'd be all over it!
I'm still running stock everything except for my muffler because I have yet to see anything that really impresses me for AutoX type applications. If PDE could make one that caters to us, I'd be all over it!
| Corey | 06-03-2002 04:12 PM |
[QUOTE][i]Originally posted by KC [/i]
[B]Or a 3rd here. ;)
(I barely hit another cone... reported "By an inch or less" and because of that came in 2nd in STX at the Tour. Doh!)
--KC [/B][/QUOTE]
No way KC! You Smashed that cone (and quite a few others...)
Corey (took 3rd in STX at Rome because of KC;))
[B]Or a 3rd here. ;)
(I barely hit another cone... reported "By an inch or less" and because of that came in 2nd in STX at the Tour. Doh!)
--KC [/B][/QUOTE]
No way KC! You Smashed that cone (and quite a few others...)
Corey (took 3rd in STX at Rome because of KC;))
| bullseye17 | 06-03-2002 05:37 PM |
ya! well i hit more than both of you!:lol: :lol: :devil: hehe
| AWMIII | 06-03-2002 06:08 PM |
What cones? I think the cones had PMS
| GoodFinder | 06-03-2002 06:54 PM |
It's great to see vendors respond to real needs and in such a quality manner. Kudos to Ian and PDE for their involvement here.
GoodFinder :)
GoodFinder :)
| z3coupe | 06-04-2002 01:17 AM |
[QUOTE]I'm still running stock everything except for my muffler because I have yet to see anything that really impresses me for AutoX type applications.[/QUOTE]
One word - SUPERTRAPP!!!!!!!
I have been using them for years, and on many cars. Nothing like it, and nothing else sounds like it. But oh, . . . . it works too! As a matter of fact, whith no cats at teh moment, on the street I run with 18 discs to keep it quieter a bit. And you know what? I may loose a bit on top end, but damn it feels better than wide open on the lowend!
One word - SUPERTRAPP!!!!!!!
I have been using them for years, and on many cars. Nothing like it, and nothing else sounds like it. But oh, . . . . it works too! As a matter of fact, whith no cats at teh moment, on the street I run with 18 discs to keep it quieter a bit. And you know what? I may loose a bit on top end, but damn it feels better than wide open on the lowend!
| z3coupe | 06-08-2002 02:47 AM |
UPDATE
Sadly, Ian was not able to get a free flow cat that he liked yet, to put on my car. So I will be running this Sunday cat-less again. But at least this time I'll have the MRT POD filter on, which seems to work quite well with his system so far. Driving it on the street is a dream! The response is excellent, and the lowend really seems to be much better. And even runnig with about 18 discs on my "Trapp", the backpressue is not hurting the power noticably. Oh, and that SOUND!!!!!! Damn I want to toss my radio out to never use it again (and save on weight too hahaha)!
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