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The Official "RX8 in DSP" Thread

Old Aug 4, 2016 | 10:24 AM
  #376  
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Some have said that fuel starvation problems are indicative of a failing fuel pump. I have no idea why. I've never had fuel starve without the low fuel light on though and once even ran out of fuel on a test-n-tune course because I expected it to starve before actually dying, but it didn't. It does seem that fuel starvation stories vary a lot though, but I can't figure out why that would be the case.

As for oil, when you say you overfilled it, do you mean filling past the full mark? Or just higher than the lower mark that still means it's ok? I've never had the light come on (except once at Toledo when a cone must have broken the connector to the level sender) and I'm not as careful about my oil level as I probably should be.
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Old Aug 4, 2016 | 10:47 AM
  #377  
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Originally Posted by Kennetht638
Some have said that fuel starvation problems are indicative of a failing fuel pump. I have no idea why. I've never had fuel starve without the low fuel light on though and once even ran out of fuel on a test-n-tune course because I expected it to starve before actually dying, but it didn't. It does seem that fuel starvation stories vary a lot though, but I can't figure out why that would be the case.

As for oil, when you say you overfilled it, do you mean filling past the full mark? Or just higher than the lower mark that still means it's ok? I've never had the light come on (except once at Toledo when a cone must have broken the connector to the level sender) and I'm not as careful about my oil level as I probably should be.
I've had somewhat similar confusing experiences with the fuel pump...autocrossed with the fuel warning light on and no starvation issues, but had it die on my twice while driving on the street with almost 1/4 tank. The car has had the fuel pump replaced twice by the previous owner, already.

The most recent time it died, I added ~1.5 gallons from a jug and it still took maybe a good minute of priming, priming, attempted start, repeat. Considering that, I'm thinking the pump was overheated. So, running at low fuel levels is possible but maybe causes the pump to overheat, due to lack of cooling via fuel immersion. Probably time for another pump (OEM this time for sure). :P
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Old Aug 4, 2016 | 10:55 AM
  #378  
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Originally Posted by Nathan Atkins
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
Good to know. In my s2, I have not had my oil light come on despite running down to a quart below max in the dipstick (at which point I top it off). Could be the higher oil capacity on the s2 helps?

My fuel will cut out consistently once I am down to 1/3 of a tank (5 gallons left). Last time it seemed to do it sooner than that, perhaps close to 1/2 a tank. This is coming out of a fast and long left hander and then going uphill (T8 to T9 at Thunderhill). I pull about 1.2-1.3G through this turn and it is mostly taken full throttle. Given the two preceding left hand turns this might be pretty much a worst case scenario for the 8 :-)
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Old Aug 4, 2016 | 11:03 AM
  #379  
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Originally Posted by Kennetht638
Some have said that fuel starvation problems are indicative of a failing fuel pump. I have no idea why. I've never had fuel starve without the low fuel light on though and once even ran out of fuel on a test-n-tune course because I expected it to starve before actually dying, but it didn't. It does seem that fuel starvation stories vary a lot though, but I can't figure out why that would be the case.
I expect experience is going to vary quite a bit depending on the course and the way the car is driven. In an autocross, you're never going to be turning for that long, and you're also not using a lot of throttle in the turns. A freeway on ramp could be worse if you are on it for a few s, and happen to go full throttle most of the way around (full throttle means the pump is not able to return as much fuel to the LHS of the tank).

The worst case scenario for me (as mentioned above) is on a high speed section (so mostly full throttle) on an anticlockwise road coarse. It's basically hard left, then left at full throttle, then a long left with a little lift to get the car turned in, then full throttle up hill, and then the fuel cuts...
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Old Aug 4, 2016 | 11:44 AM
  #380  
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The far turnaround at Toledo was a sustained 5-10 seconds at full speed, like an exit ramp. By overfilled I mean it was above the full mark on the dipstick, I was actually became concerned about over pressure.
I once connected a fuel gauge and taped it to the windshield and did a number of aggressive maneuvers and was 58-62psi the whole time
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Old Aug 4, 2016 | 06:24 PM
  #381  
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I had pretty much discounted oil starvation as a potential problem, guess I might want to think about it now...


The changing fuel starvation is something we have experienced in the suby world. Many people have reported it getting worse and then at a later date having the pump fail. I think there is a relationship between being run low frequently and starvation on course. Probably having to do with the pump overheating. I generally run the suby full and 7 seasons later it will run out of fuel before starving. Proof? No not really, but I think it is indicative.
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Old Aug 5, 2016 | 11:30 AM
  #382  
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Originally Posted by Nathan Atkins
The far turnaround at Toledo was a sustained 5-10 seconds at full speed, like an exit ramp. By overfilled I mean it was above the full mark on the dipstick, I was actually became concerned about over pressure.
I once connected a fuel gauge and taped it to the windshield and did a number of aggressive maneuvers and was 58-62psi the whole time
We used to run the BS RX-8s (back in the Kumho V710 days) down to the fuel light at Nationals. Even at Forbes field we never got fuel starve in sustained turns. That's how we got those cars down to 2800 lbs crossing the scales.

A failing fuel pump shouldn't cause fuel starve, but the pre-filter can get clogged with silt at the bottom requiring the fuel level to be higher (so it draws from the top of the filter) before fuel starvation. Something to consider.
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Old Aug 5, 2016 | 11:53 AM
  #383  
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Originally Posted by ion_four
Actually, that's the pan I was thinking of, since I've seen them for sale on eBay.
Great! They have/are becoming very popular with the AutoX, Rally and track day guys over the last few years. Not sure if they will be on Ebay again however, doing so will drive the cost up further so they likely will be available on the website exclusively.

Please contact me directly @ Scott@RX8Performance.com if you have any questions!

Thank you,
Scott
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Old Aug 13, 2016 | 11:36 PM
  #384  
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Didn't seems to have any problems tonight, but of course this was a FedEx which has less grip than Toledo. The revalved dampers work much better than the off the shelf valving. There are some significant bumps at this lot that have given me trouble that were really a non issue tonight. They're not the perfect solution, but it's what I've got for now. I'm going to take some action on weight reduction, with exhaust and trailer hitch removal, probably could get 5# just by vacuuming the inside.

Fun night, looking forward to more :-)

Last edited by Nathan Atkins; Aug 15, 2016 at 08:11 AM.
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Old Aug 15, 2016 | 11:50 PM
  #385  
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My Buddy AJ got some cool shots, more on my fb page :-)



WDCR 8/14/16 night Autocross, sunset runs
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Old Aug 17, 2016 | 04:16 PM
  #386  
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The more seat time I get on the Hoosiers the more I understand how they work and how youre supposed to drive on them. I'm looking at having right about 50 runs experience on them when I get to Nationals, lets hope it's enough!
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Old Aug 17, 2016 | 05:07 PM
  #387  
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When your new to purple crack, every time you think you've found the limits, you mess up and realize you haven't.
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Old Aug 25, 2016 | 08:51 AM
  #388  
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From SCCAforums you pick the winners poll heheh I have a fan!
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Old Aug 25, 2016 | 09:04 AM
  #389  
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Hey guys, I officially joined DSP. So far the car only has coilovers, wheels, tires, front sway (new Mazda speedway style bar), and a catless midpipe. First outing the car took top pax against some good cars and drivers. Car was pretty good, and mindblowingly fun.

Just as a heads up I went with the 17x10+52 949 6UL wheels with 275/35/17 A7s. The rear required 5mm spacers and limited camber in order to avoid hitting inboard on the sheet metal surrounding the shock. The fronts fit without even rolling, but the tire does rub inboard just a tiny bit too. Not enough to require spacers in our opinion. Just wanted to share that info in case anyone is thinking of going with the same wheels.
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Old Aug 25, 2016 | 11:51 AM
  #390  
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If anyone is in need of tires. I've got 2 sets of A7's for sale and 1 set of A6's.

275/35/17 A6's from last year. 40 runs. $700
275/35/17 A7's from this year. 60 runs $650
275/35/17 A7's from 1 month ago. 10 runs. $1000

I can transport to nationals if anyone is interested!
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Old Aug 29, 2016 | 12:55 PM
  #391  
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ooooo any one of those is a pretty good deal Mike! I ended up going with 18's though so I'm out.


Big congrats to Tamra for the car getting top pax on it's debut! I cant wait to see more of her!


I got a chance to see Amy and Marc at NNJR yesterday, serenity is looking ready for Nats! I'm getting pretty excited now haha one more work week left to get through!
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Old Sep 7, 2016 | 11:22 PM
  #392  
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I know Marc and I are stoked! I saw Mike's car but haven't seen him around yet.

Wish us luck folks!
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Old Sep 8, 2016 | 05:08 AM
  #393  
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Good luck today!
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Old Sep 8, 2016 | 12:43 PM
  #394  
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Wow! Very nice first day Mike. Strength-strength how does tomorrow's course look for the 8vsbmw?

Glad to see a decent turn out of rx8
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Old Sep 8, 2016 | 07:42 PM
  #395  
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Tomorrow's course looks pretty fun to me, so i'm gonna go out and have some fun!
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Old Sep 8, 2016 | 09:17 PM
  #396  
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Great!
Stay loose
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Old Sep 9, 2016 | 11:45 AM
  #397  
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Congrats Mike! Nice friggin' driving!
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Old Sep 9, 2016 | 04:33 PM
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Yes indeed! Congratulations Mike! And Marc was only .4 out of trophies.


Hope everyone had fun.
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Old Sep 11, 2016 | 03:39 PM
  #399  
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Big Congratulations to Mike for the superb performance! Nice to meet you out there finally

Marc good to see you as always, I think you and I both were able to identify what happened and where we need to go from here, and we'll come back stronger next year!

My buddy Marcus is pretty quick so I think our times were representative of where the car is at, I'm trying to decide now on a serious prep for DSP for just half-*** prepping my own car(which is my practical budgetary limit) and doing co-drives for big stuff :-)

Still, I had fun, no regrets!
Until next year!
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Old Sep 12, 2016 | 10:50 AM
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Great job in DSP Mike! That day one gap to first was pretty incredible, and I was excited to see you hanging on to 2nd place through day 2.

I did a fly and drive this year, so not a lot of time to hang out. I got to chat with Marc a bit at the practice course, but didn't end up getting to see the rest of you guys. Maybe when I actually have my RX-8 back out, I'll see RX-8 people more.
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