The STX thread!
08-17-2009, 02:59 PM
#276
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So is Karl still taking his car to Nat'ls or is he pushing to dual drive yours?
So I've fallen a little bit behind with this thread but has anyone tried out the Exotic Speed mid pipe + highflow cat Brice is carrying? From the pictures it definitely looks STX legal and at $550 it's definitely cheaper than getting one fab'ed up.
Last edited by Anijo; 08-17-2009 at 03:06 PM.
08-17-2009, 03:09 PM
#277
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I can't remember what the Davesport cat cost, but it was under $150. The RX7store midpipe was $200. I think I paid a shop $100 to do a real shitty job welding the cat into the pipe.
That might be cheaper, I'm not sure. You said the other one was 'definitely' cheaper, and I'm easily swayed by conviction.
08-17-2009, 03:40 PM
#278
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I have not heard of this midpipe. Link, please.
I can't remember what the Davesport cat cost, but it was under $150. The RX7store midpipe was $200. I think I paid a shop $100 to do a real shitty job welding the cat into the pipe.
That might be cheaper, I'm not sure. You said the other one was 'definitely' cheaper, and I'm easily swayed by conviction.
I can't remember what the Davesport cat cost, but it was under $150. The RX7store midpipe was $200. I think I paid a shop $100 to do a real shitty job welding the cat into the pipe.
That might be cheaper, I'm not sure. You said the other one was 'definitely' cheaper, and I'm easily swayed by conviction.
It has a resonator, which I guess for a pure STX setup is adding unnecessary weight but for those of us who still daily drive our cars, it's a nice touch. Where is this $200 mid-pipe you speak of though? That's really intriguing
After I posted that, I was also pointed at this one from RP: http://rx7.com/store/rx8/rx8exhaust.html
08-17-2009, 04:06 PM
#279
Two Piece Rotors: STX Legal?
Just Wondering what you guys think about the Two Piece Rotors offered by Racing Brake? I know that rotors of the same size, or bigger are STX legal. But I have not been able to find if the two piece rotors are outlawed or not? They save about 4.4 lbs on the fronts and 2.4 lbs in the rear.
Think it's worth it?
-Mike
Think it's worth it?
-Mike
08-17-2009, 04:47 PM
#280
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http://www.fluidmotorsports.com/p-93-exhaust.aspx scroll down.
It has a resonator, which I guess for a pure STX setup is adding unnecessary weight but for those of us who still daily drive our cars, it's a nice touch. Where is this $200 mid-pipe you speak of though? That's really intriguing
After I posted that, I was also pointed at this one from RP: http://rx7.com/store/rx8/rx8exhaust.html
It has a resonator, which I guess for a pure STX setup is adding unnecessary weight but for those of us who still daily drive our cars, it's a nice touch. Where is this $200 mid-pipe you speak of though? That's really intriguing
After I posted that, I was also pointed at this one from RP: http://rx7.com/store/rx8/rx8exhaust.html
I have heard of people having problems with the RP supercats. I haven't used one myself.
My midpipe does not have a resonator. When I first had the pipe installed on my car, I decided right away it needed a resonator. I haven't gotten around to doing that, though, and in the meantime I've gotten used to it. Yeah, the car's loud, but it's not unbearable.
08-17-2009, 05:05 PM
#281
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Just Wondering what you guys think about the Two Piece Rotors offered by Racing Brake? I know that rotors of the same size, or bigger are STX legal. But I have not been able to find if the two piece rotors are outlawed or not? They save about 4.4 lbs on the fronts and 2.4 lbs in the rear.
STX and STU: Non-standard brake rotors may be used provided
they are of equal or larger dimensions (diameter and thickness)
and made of ferrous material (e.g. iron). Aluminum rotor hats
are allowed.
The fact they require iron rotors and allow aluminum rotor hats pretty much says 2 piece is allowed.
08-17-2009, 09:25 PM
#284
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Jason, did the laps on street tires at Auto Club Speedway, back when we did the test day (Shelby vs. 335i) for SportsCar have any influence on your decision to go to STX? I, for one, was amazed how good the RX8 felt on decent street tires, with just the BS set up...I can see why STX is so appealing to you and the other RX8 guys who have gone (or are going) in that direction. It almost makes me want to get another RX8 and give it a try...almost
08-17-2009, 09:35 PM
#285
Jason, did the laps on street tires at Auto Club Speedway, back when we did the test day (Shelby vs. 335i) for SportsCar have any influence on your decision to go to STX? I, for one, was amazed how good the RX8 felt on decent street tires, with just the BS set up...I can see why STX is so appealing to you and the other RX8 guys who have gone (or are going) in that direction. It almost makes me want to get another RX8 and give it a try...almost
The only appealing thing to me is I don't have to spend another weekend working on the car this year.
StreetTiresSuck.
p.s. if you thought the Pilot Sport PS2 were good, you need to get out more.
08-17-2009, 10:04 PM
#286
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BTW, at the time, those were the only dry laps I had on any street tire other than the two on the oem RX8 Bridgestones, which did suck (I never ran the Z06 on street tires, other than a rain event). Since then, I've taken a few laps in a STS Miata on RE-11's and not only went really fast, but enjoyed it. I think you're wrong, street tires don't suck. They're better than the old Victoracers and RA-1's I ran in open track, these days, and make lots of sense for many autocross competitors.
08-17-2009, 11:06 PM
#289
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08-18-2009, 03:27 PM
#291
I installed a new O2 sensor, and my car is no longer throwing codes, so I can report this with confidence:
On Surgeline's Mustang dyno, in 4th gear, my car made 208 RWHP/145 TQ, with a K&N drop-in, Corksport catback, custom mid-pipe using Davesport cat & RB resonator, and of course a Cobb AP & custom tune by Surgeline.
Not huge numbers, but not bad. As a comparison, my car made 180 Hp on a Dynojet before I had the mid-pipe & AP. I'll post a dyno graph of the new setup in the dyno thread once I have a digital copy.
Tim at Surgeline richened the mixture, as compared to the Cobb Stage I map, which made a bit more power & torque across the range, and (apparently) cooled things off at the same time. He also tweaked the timing, etc. Made passes in 2nd, 3rd, and 4th gears. Tim is very thourough & takes his time to do it right.
Also, in addition to my comments earlier in this thread about the sound of my custom mid-pipe, I will say that while the car is louder with the windows down, it is quieter than the stock cat-pipe with the windows up. This is interesting - I think relocating the resonator up-stream helps somehow. It's as if there is less sound insulation in the back seat & trunk area, or the sheet metal is thinner. This is consistent with my observation that tossing a blanket in the trunk quiets things down as well.
Not that it matters for racing, but I get lots of comments about how good the car sounds when autocrossing. Tim said the car got into his head and rattled him a bit after all those pulls, but that he really liked how it sounded as well. It was great to sit in the waiting room and hear it howl.
So, now that I've got the codes excised from the system, I'm really liking the combination of the Davesport cat & RB resonator. I suspect it would make more power than some of the aftermarket solutions, given the cell count of the Davesport cat vs. others, but I don't know that for sure.
On Surgeline's Mustang dyno, in 4th gear, my car made 208 RWHP/145 TQ, with a K&N drop-in, Corksport catback, custom mid-pipe using Davesport cat & RB resonator, and of course a Cobb AP & custom tune by Surgeline.
Not huge numbers, but not bad. As a comparison, my car made 180 Hp on a Dynojet before I had the mid-pipe & AP. I'll post a dyno graph of the new setup in the dyno thread once I have a digital copy.
Tim at Surgeline richened the mixture, as compared to the Cobb Stage I map, which made a bit more power & torque across the range, and (apparently) cooled things off at the same time. He also tweaked the timing, etc. Made passes in 2nd, 3rd, and 4th gears. Tim is very thourough & takes his time to do it right.
Also, in addition to my comments earlier in this thread about the sound of my custom mid-pipe, I will say that while the car is louder with the windows down, it is quieter than the stock cat-pipe with the windows up. This is interesting - I think relocating the resonator up-stream helps somehow. It's as if there is less sound insulation in the back seat & trunk area, or the sheet metal is thinner. This is consistent with my observation that tossing a blanket in the trunk quiets things down as well.
Not that it matters for racing, but I get lots of comments about how good the car sounds when autocrossing. Tim said the car got into his head and rattled him a bit after all those pulls, but that he really liked how it sounded as well. It was great to sit in the waiting room and hear it howl.
So, now that I've got the codes excised from the system, I'm really liking the combination of the Davesport cat & RB resonator. I suspect it would make more power than some of the aftermarket solutions, given the cell count of the Davesport cat vs. others, but I don't know that for sure.
08-20-2009, 07:32 AM
#294
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I'm looking forward to meeting everybody in Lincoln, as well.
08-20-2009, 08:24 AM
#295
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08-20-2009, 09:43 AM
#296
The custom tune from Surgeline helped. I'm going back for some tweaks to bump the midrange next week, and I'll post the graph then. But for now, in the high end (above 6k), I'm seeing 2 to 5 ft-lbs more than the Cobb Stage I map, and the torque dips due to system resonances are less significant. Also, these numbers are from 3rd gear pulls (for some reason he did the baseline in 3rd). In fourth, the differences would be slightly greater (third gear made 130 ft-lbs, 4th made 145).
Unfortunately, the baseline pull was done using the Cobb Stage I map, so I don't know how much I',m getting over the stock map. I will say that the Cobb Stage I map is very lean, as others have said, and my new map is much safer, runs cooler, and makes more power & torque, so it's hard to argue with it.
Last edited by GeorgeH; 08-20-2009 at 09:50 AM.
08-27-2009, 07:27 PM
#300
Brought the car back to Surgeline today, to get a little more torque in the lower-midrange, which Tim found. Not only that, he found a little more top end too, for a nice even 210.
https://www.rx8club.com/showpost.php...&postcount=598
https://www.rx8club.com/showpost.php...&postcount=598