The Official "RX8 in DSP" Thread
V8 Traitor
Joined: Oct 2011
Posts: 600
Likes: 5
From: Abingdon, Harford County, MD
I congratulated you off of the forums! 
So my S2000 recently sold (DSP funding: check!) and I'm about to dive into DSP with my 05 RX8. We will be DIYing aero, my coilovers are decided (So $$$), going to go catless. Tuning solution TBD. Spring rates TBD. Wheels TBD. Sticking with the OEM diff.
For wheels, I've been wavering between 17x10 and 18x10 options. I'm leaning toward 17x10 with 275/35/17, since it's not much narrower than the 285/30 option, is slightly shorter in overall diameter, and has a slightly taller sidewall (which I prefer the feeling of).
I can't find much info on the forums about the 17x10 949 6UL's but they are at the top of my list right now. I would love to try 315's in the future but for my initial sampling, this seems like an easy button. Opinions?
I'm also really excited - going to drive Marc's car at the Wilmington Tour.
So my S2000 recently sold (DSP funding: check!) and I'm about to dive into DSP with my 05 RX8. We will be DIYing aero, my coilovers are decided (So $$$), going to go catless. Tuning solution TBD. Spring rates TBD. Wheels TBD. Sticking with the OEM diff.
For wheels, I've been wavering between 17x10 and 18x10 options. I'm leaning toward 17x10 with 275/35/17, since it's not much narrower than the 285/30 option, is slightly shorter in overall diameter, and has a slightly taller sidewall (which I prefer the feeling of).
I can't find much info on the forums about the 17x10 949 6UL's but they are at the top of my list right now. I would love to try 315's in the future but for my initial sampling, this seems like an easy button. Opinions?
I'm also really excited - going to drive Marc's car at the Wilmington Tour.
Heh I know and thank you :-) I'm sort of aware of some of your progress and am anxious to see how it develops. Im interested particularly in the tire choice. I ended up going with the 18's just because I was advised Id end up on them eventually, and I think the cast offs will be easier to come across. IIRC Mike Kuhn was using the 17's at first also, maybe he can comment on that.
Hey Mike! what's the word, you coming to Nationals this year? Marc and I are registered and I may be dragging along a codriver too. Any development? The opposition has had a lot, particularly Vitamvas who's car is "significantly faster than last year"
V8 Traitor
Joined: Oct 2011
Posts: 600
Likes: 5
From: Abingdon, Harford County, MD
Congratulations to Mike for taking home final trophy at the Wilmington tour! Those BMW guys are going to be tough in Lincoln. Eric has a lot of pace this weekend! JV has been beating him pretty regularly but he must have found something special out there.
Thanks guys. One of the worst courses I have driven at a national event in 6 years. Nothing but sharp turns followed by 30-70mph acceleration zone where the cones were so far apart they didn't slow you down at all. So being under powered it didn't help my case. Time to start making some changes to the car before nationals
V8 Traitor
Joined: Oct 2011
Posts: 600
Likes: 5
From: Abingdon, Harford County, MD
I'll be going to nationals with a number of unproven changes too, hopefully they all work ok!
My Bilsteins are at Bilstein NC getting revalved to suit my springs, I'm currently on 10k/7k but I'm ordering 14k's for the front of the car and moving the 10's to the rear.
I'm going to install Whiteline eccentric bushings on my front UCA's, anyone know of a method to keep them from rotating? keying? stop bolt?
I'm trying to get a lighter, less obnoxious exhaust as well, I have the full catted Turbo XS setup currently, and the header to midpipe gasket is blown out. I had hopes to get a nice burns 3-1 and lengthen the header runners some but I don't think I have the time/budget to get it done in time.
I'll probably remove my 40 pound trailer hitch too :-)
My Bilsteins are at Bilstein NC getting revalved to suit my springs, I'm currently on 10k/7k but I'm ordering 14k's for the front of the car and moving the 10's to the rear.
I'm going to install Whiteline eccentric bushings on my front UCA's, anyone know of a method to keep them from rotating? keying? stop bolt?
I'm trying to get a lighter, less obnoxious exhaust as well, I have the full catted Turbo XS setup currently, and the header to midpipe gasket is blown out. I had hopes to get a nice burns 3-1 and lengthen the header runners some but I don't think I have the time/budget to get it done in time.
I'll probably remove my 40 pound trailer hitch too :-)
Eric is always fast in Wilmington. That place is an anomaly in terms of grip and requires a unique setup (we didn't have it) to eliminate the resulting push. The courses were pretty boring in a DSP car - floor it and ride the rev limiter. No transitions to speak of.
If I hadn't just blown up an oil pump I might have gotten more aggressive with the rev limiter setting and I should have tried to do something about the push we fought all weekend. It is what it is, Eric shellacked all of us and I'm not going to worry about it too much, neither should you.
I really wish I had found the time to get the taller rear gear in for this weekend. A 65MPH top speed in 2nd was not the fast way around that course.
If I hadn't just blown up an oil pump I might have gotten more aggressive with the rev limiter setting and I should have tried to do something about the push we fought all weekend. It is what it is, Eric shellacked all of us and I'm not going to worry about it too much, neither should you.
I really wish I had found the time to get the taller rear gear in for this weekend. A 65MPH top speed in 2nd was not the fast way around that course.
Last edited by John V; Jul 25, 2016 at 09:00 AM.
Congrats to Mike and John V for the trophies! I would have come by the DSP grid to say hi, but it was way too damn hot to be outside when I didn't have to. Eric was crazy fast out there. I can only imagine what it was like sitting through those loooong straightaways in the RX-8 thinking about how much time you're losing to the BMW's. I've never had so much time to look ahead (and around at the scenery) on an autocross course before.
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Thanks guys. One of the worst courses I have driven at a national event in 6 years. Nothing but sharp turns followed by 30-70mph acceleration zone where the cones were so far apart they didn't slow you down at all. So being under powered it didn't help my case. Time to start making some changes to the car before nationals
This seems typical of the wilmington courses lately... I remember last years tour was like this as well. I will be looking forward to see what the RX-8's in DSP do at nationals.. If mine doesnt sell DSP may be an option.
Congrats to Mike and John V for the trophies! I would have come by the DSP grid to say hi, but it was way too damn hot to be outside when I didn't have to. Eric was crazy fast out there. I can only imagine what it was like sitting through those loooong straightaways in the RX-8 thinking about how much time you're losing to the BMW's. I've never had so much time to look ahead (and around at the scenery) on an autocross course before.
There were only two corners I'd consider a dig (around 35MPH), everything else my corner entry speed was above 45MPH. I have to imagine in an RX-8 they were even faster.
Also, thanks Kenneth... but being two seconds off the pace I don't feel particularly happy about that "trophy." Congrats on the win.
Last edited by John V; Jul 25, 2016 at 11:50 AM.
John i'm also topping out at about 65 in second gear. Running a 275/35/17 doesn't help my gearing at the top end.
And i'm not sure my cornering speed would be faster on a 275 vs your 315s.
And i'm not sure my cornering speed would be faster on a 275 vs your 315s.
V8 Traitor
Joined: Oct 2011
Posts: 600
Likes: 5
From: Abingdon, Harford County, MD
sounds like third gear was the play on those long parts.
long gearing is fine if you have the torque to spread out, and anything over a second or two on the limiter and it would have been worth going to third.
A 35mph corner is 5krpm in my car which is the fattest part of the torque curve, RX8's are generally underpowered compared to the BMW but I don't think this was an Achilles heel, we just need to take advantage of superior cornering grip to have higher exit speed to make up the deficit.
Kenneth what do we need to do to fit 315's? :-)
long gearing is fine if you have the torque to spread out, and anything over a second or two on the limiter and it would have been worth going to third.
A 35mph corner is 5krpm in my car which is the fattest part of the torque curve, RX8's are generally underpowered compared to the BMW but I don't think this was an Achilles heel, we just need to take advantage of superior cornering grip to have higher exit speed to make up the deficit.
Kenneth what do we need to do to fit 315's? :-)
sounds like third gear was the play on those long parts.
long gearing is fine if you have the torque to spread out, and anything over a second or two on the limiter and it would have been worth going to third.
A 35mph corner is 5krpm in my car which is the fattest part of the torque curve, RX8's are generally underpowered compared to the BMW but I don't think this was an Achilles heel, we just need to take advantage of superior cornering grip to have higher exit speed to make up the deficit.
long gearing is fine if you have the torque to spread out, and anything over a second or two on the limiter and it would have been worth going to third.
A 35mph corner is 5krpm in my car which is the fattest part of the torque curve, RX8's are generally underpowered compared to the BMW but I don't think this was an Achilles heel, we just need to take advantage of superior cornering grip to have higher exit speed to make up the deficit.
Former Sponsor
Joined: Apr 2015
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From: RX8Performance.com
High Capacity Oil Pan by RX-8 Performance | RX8Performance.com
Scott
Not sure if you are aware of this option Nathan:
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Scott
High Capacity Oil Pan by RX-8 Performance | RX8Performance.com
Scott
As far as fuel starvation, the Holley Hydramat would require some messing around with the stock pump/sump can assembly AND is $149 for the cheapest one, but the demonstrations I have seen showed it being soaked in fuel, and a car taking a few laps around a track after the tank was otherwise drained.
I most definitely have fuel starvation issues.
V8 Traitor
Joined: Oct 2011
Posts: 600
Likes: 5
From: Abingdon, Harford County, MD
I never had the fake oil gauge on the dash drop, and no official instrumentation on it, but the oil light came on mid run in Toledo on the big sweeper at the far end a few times, I just overfilled and that seemed to help. Likewise with gas, I was getting fuel cut out until I filled it about 5/8 tank