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Old 10-08-2009, 11:34 AM   #21
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Originally Posted by j_man View Post
IMO that is too soft
It is. I still want to drive this on the street, and to/from autocross and track days. I will rock the 550/350 next year.

I started a thread on mnet for folks to weigh in on streeting a serious autocross car. Hollis weighed in that a 750 front can still be street driven, with the right shock (very important) and a softer tire. If the 550/350 isn't heavy enough, and my kidneys are still intact (******** NE roads), next year I will send the billies back to Shaikh to revalve for a more manly spring, along with the DA can$, of course.

There has to be a diminishing return on a heavy spring, right? Especially considering all local sites I run on are bumpy, at best. At worst, pavement breakage, big heaves, nasty pavement transitions. A 1000 may be wrong for those conditions, right?
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Old 10-08-2009, 01:57 PM   #22
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Cool that you guys have such a deep ssm pool there in Tenn. Guys, what's the deal with the fd at nats? The one that Brian Johns is driving was not the only fast fd this year. Those were all n/a, right? I know with the right port work, the rotary can go mild to wild and everywhere in between. They also have less of an issue fitting large rubber, correct? And maybe they can be run lower than the miata? It may not be all about weight, as the fd Brian Johns will be in next year was not as light as it could be per the rules. I do know there were weather issues during the runs, though, could have effected the outcome.

Midtenn, I looked and didn't see anything on your build. Can you fill us in? FI or na? Turbo or blower? V6? 1.8? Judging from your target weight, it looks like a 1.8 turbo, but... Also, what for suspension, wheels, tires, diff?
SSM is going to be fast in TN! We have Dan Chadwick (2009 SSM National Champ), myself (2007 ES National Champ), Midtenn (Andrew Cowden, 2009 ASP trophy winner), Carter Thompson (Mulit time Pro Solo Champ) and his dad Jim (former National Champ) are in the process of building an FD for SSM too!

The FD's at Nats were all turbo but all different. Dan and I run a twin turbo 2 rotor, Andy McKee runs a single turbo 2 rotor, and Erik Strelnieks runs a single turbo 3 rotor. Erik has to add weight to his car to be legal, Andy is close to minimum, and Dan an I need to lose around 200 lbs over the winter.

Andrew is building turbo 1.8 but I don't know all the rest of the specifics of his build so I won't speculate.

Brian

Last edited by sbrian2; 10-08-2009 at 03:58 PM.
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Old 10-08-2009, 02:46 PM   #23
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Originally Posted by Midtenn View Post
...Get a 1.5way diff. A 2way diff will tend to create a push when it locks under decel. The 1.5way allow for more slip between the tires under decel which allows for a better turn in. As SBrian2 stated, a Torsen is useless at the high grip levels of SSM...
Those are just different flavors of Torsen-type diffs, along with the Type-1.
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Old 10-08-2009, 03:32 PM   #24
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I will disagree. We changed out the torsen in Dan's RX-7 for a Kaaz and made all the difference. Also, the torsen equiped CSP car I drove early in the year recently got an OS Giken and eliminated the wheel lift induced one wheel peel that you get with a torsen. Torsens will not lock in if a wheel is in the air, where a clutch diff is locked until a certain torque is applied to overcome the friction of the clutches.
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Old 10-08-2009, 03:53 PM   #25
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I will disagree. We changed out the torsen in Dan's RX-7 for a Kaaz and made all the difference. Also, the torsen equiped CSP car I drove early in the year recently got an OS Giken and eliminated the wheel lift induced one wheel peel that you get with a torsen. Torsens will not lock in if a wheel is in the air, where a clutch diff is locked until a certain torque is applied to overcome the friction of the clutches.
+1

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Dan an I need to lose around 200 lbs over the winter.
You guys are going to have fun with that car at class min!

I read the whole thread on the SCCA forum on the ultimate NA/NB ssm build. There was back and forth over SC vs turbo. Chris' is not the only SC ssm build I've seen. I like the buffered delivery of my small/mid size turbo setup. I feel it gives the rear end some hook time at the start, as well as corner exit, before launching the barrage. It is not good for balancing on throttle, and especially in a real transition environment like slalom, because of the stepped delivery. That is, if you use throttle to balance in a slalom, which I don't think you should need to (I am not a top driver, though). This opens up the can, right?
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Old 10-08-2009, 06:01 PM   #26
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If it helps any I run 700f 450r on my Mr2 on Koni Sports non revalved. It's not bad at all on the street. It would be better with some race valved shocks in the front and if it had the motor in the front like the Miata.
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Old 10-08-2009, 06:18 PM   #27
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Webby...why not valve the shocks for 650 springs to save time, effort and money later. They can handle springs 100lb/in in either direction which covers your 550s for now and your 750s for later.

I just got some HDs...and plan on doing the same eventually...but from 450-650ish.
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Old 10-08-2009, 07:33 PM   #28
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FYI- I'm running Ohlins DFV custom 12k/8k, work great for autoX but can be harsh on the street.

CrisS- Thanks for the correction. I accidentally bumped up a page to SM when looking up the weights for SSM.
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Old 10-08-2009, 08:05 PM   #29
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Beginning of this summer I was on track to come get beat by you guys out at TR. Was going to make an appearance for ETR, but my motor blew and I'm back quite a few steps.

I plan on running the 15x9 6uls with the 275s as well. Dave Disney got his to fit in his 99 fairly easy. He's car a pretty good example of a DD/autox SSM car. He trailers his hoo-hoo's in every event, runs an older FMII setup, probly around 220-230rwhp, Koni's with GC's. Probly the easiest/cheap way to get into SSM and be "quick".

East Tenn Region is pretty small (60 cars an event usually) but FTD is usually close between Disney, a BSP Z (really a BS Z with a diff :-\) and Gebbia. The ASP vettes have disappeared middle of this season :(. Was always fun to watch them run.

I was hoping to grab a consistant FTD in ETR with my car, or at least have my friend (driver of that BSP Z) put up FTD. But hey maybe I can get everything put together quick enough

Hopefully I can come watch some of the SSM battles over at TR before I head off to AF .

Mike, I'm not sure what kind of layouts Atlanta has but Chattanooga Region recently got the BIG auto auction parking lot. Suppose to be pretty fun, I'm planning on making a few of them in my dad's STS car. Would be cool to see you and your car run .
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Old 10-08-2009, 09:52 PM   #30
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Originally Posted by Doppelgänger View Post
FYI- I'm running Ohlins DFV custom 12k/8k, work great for autoX but can be harsh on the street.
12k=672#
8k=448#

Mine will be 550/350. Yours has a stiffer relative rear roll rate. Are you running rear bar? What front bar? How does yours behave in transition and in corner entry? Not too tail happy?

Doppel, with the Ohlins and the rest of your build, you have quality ****. It looks fantastic. Great pics, too. Your eye doesn't process junk. (PM pics of your woman)
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Old 10-08-2009, 10:12 PM   #31
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Originally Posted by MicaCeli View Post
If it helps any I run 700f 450r on my Mr2 on Koni Sports non revalved. It's not bad at all on the street. It would be better with some race valved shocks in the front and if it had the motor in the front like the Miata.
Wheel rate is what really matters, and they will not be the same on your MR2 and the miata given the same spring rate, especially with the mr2's strut style suspension. So, the comparison can't really be made. (See motion ratio).

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Originally Posted by gospeed81 View Post
Webby...why not valve the shocks for 650 springs to save time, effort and money later. They can handle springs 100lb/in in either direction which covers your 550s for now and your 750s for later.

I just got some HDs...and plan on doing the same eventually...but from 450-650ish.
I fail at planning ahead. This is a reasonable idea. I may call Shaikh and see if he can adjust, but it's probably too late as I think they are going to ship next week.
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Old 10-08-2009, 11:10 PM   #32
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Originally Posted by webby459 View Post
Your car is set up very similar to mine, except my soon to be FCM revalves and (maybe) my NT-01s.



Chris, thanks for weighing in. Don't think I haven't already checked out your build page thoroughly! The best of everything, maybe something I can shoot for in the future. Are you really running out of gear to the extent that the 3.90 isn't cutting it?

Things I know: I will run the 275 hoosier next year. I will probably run the 9" 6UL. I will attempt to roll and pull the fenders to clear, but will use flares if I have to. I am running the fcm non adj revalves with 550/350 (light comparitively, but a start). I will be getting a diff, but it will probably be 4.1 whether it's my open filled with an os giken, or a torsen. I will have a freshened engine, whether it's my 1.6 built or a 1.8 lb, built a bit less to save a bit of ching.
It's not a matter necessarily of running out of gear. I have spent the last few years building and adjusting my car to mask my many deficiencies behind the wheel. At my current power levels, I tend to roll the throttle on too quickly and get some wheel spin on corner exit. Swapping to the 3.63 will not only give me a few more mph, but may help reduce the wheel spin on exit. The torque curve on my car is such that dropping the 300 rpm or so on any corner exit from 35 mph to 50 mph, I am still going to be in the 250 ft/lb area. I still have some tuning to do, and expect more power out of the motor. I need to get my knock sense dialed in, and possibly larger injectors. Once those things are in place, I think I have room for more timing, which is where the real power is.

I run the torsen diff in my car, but my spring rates are such that although I do transfer some weight off the inside tire, it is never enough to unlock the torsen. One idea I have been bouncing around in my head is to reduce the front caster to keep more weight on the inside rear wheel. I may play with that some in the off season but it really hasn't been an issue yet. You need a limited slip of some type. I haven't driven the OS Giken, but am tempted too. One benefit of the torsen over any of the clutch type diffs is maintenance. You don't have to adjust it and it will work the same until you break it. The down side is that you can't adjust it. It's a two edged sword.


My rates are probably at the upper edge of diminishing returns. I ran 750/400 last year and upped them to 1050/400 this year. Most of our lots are fairly smooth. On a rougher surface it might be too much. The old saying is "stiffer is faster, until it's not". I am not sure I am there yet but I think I am surely pretty close.


I have a picture somewhere of two stacks of 275s. One set on 10" wheels the other on 10.5". There is a noticeable difference in the height of the stacks. The 6ULs are great wheels, and a great value, but IMO they are not wide enough for 275s on a national level autocross car.
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Old 10-08-2009, 11:26 PM   #33
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Mike, I'm not sure what kind of layouts Atlanta has but Chattanooga Region recently got the BIG auto auction parking lot. Suppose to be pretty fun, I'm planning on making a few of them in my dad's STS car. Would be cool to see you and your car run .

We get some good ones at Turner Field and Atlanta Motor Speedway. I've managed to get into 3rd geat (6spd/3.9diff) at most events. We've had fast courses that the front runners are in the mid-60's to some that were down to high 40's.

I wouldn't mind coming up to an event in Chat. and checking it out Well see how next year pans out.


BTW in my region, only 3.47 points seperate the SSM leader and 2nd place......and i'm in second place with one event to go...talk about "down to the wire".
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Old 10-09-2009, 12:07 AM   #34
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Originally Posted by webby459 View Post
Midtenn, I looked and didn't see anything on your build. Can you fill us in? FI or na? Turbo or blower? V6? 1.8? Judging from your target weight, it looks like a 1.8 turbo, but... Also, what for suspension, wheels, tires, diff?
Everything is in flux with the car right now. I recently put a 96 motor with a FMII kit (T28) in the car. I don't have an ECU, so besides starting and warming up in the driveway, I'm waiting to start actually driving the car and really starting to sort the car out. Here is the plan as I see it right now (just the basics, no details b/c they may change):

Motor and driveline:
- Hopefully next winter (2010) I'll swap to a 99+ motor, clean up the ports on the head, maybe some rods and pistons. Nothing special really. Just need something to reliably run about 8-8.5k (yes I know there isn't power up there, just saves that extra upshift on some courses)
- GT2560
- 300whp / 250ft*lb goal
- E85
- KAAZ 1.5way or OS Giken LSD w/ a 4.1 rear.

Suspension:
- Koni Race Dampers (short term until I can bite the bullet for double adjustables)
- 600/350 spring rates
- RB 1.125" hollow front sway bar
- tubular upper control arms
- Delrin bushing equiped lower control arms (tubular later)
- 15x9 ULs w/ 275/35R15's to start with. Eventually I'll go with 15x10's.

Interior:
- Standard CSP job. Remove the rest of the AC, soft top, radio, seat belts ect. I have to check on a proposed rule that allows me to just remove the passenger side air bag without having to do the whole dash swap.
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Old 10-09-2009, 05:27 PM   #35
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Originally Posted by Chris Swearingen View Post
At my current power levels, I tend to roll the throttle on too quickly and get some wheel spin on corner exit. Swapping to the 3.63 will not only give me a few more mph, but may help reduce the wheel spin on exit.

I run the torsen diff in my car, but my spring rates are such that although I do transfer some weight off the inside tire, it is never enough to unlock the torsen.

I ran 750/400 last year and upped them to 1050/400 this year.

I have a picture somewhere of two stacks of 275s. One set on 10" wheels the other on 10.5". There is a noticeable difference in the height of the stacks. The 6ULs are great wheels, and a great value, but IMO they are not wide enough for 275s on a national level autocross car.
Chris, you want a strong turbo setup, lag is my friend and can be your's, too. What about tc? I was speaking with a guy last weekend that tunes AEM, he says they have a tc setup that works without wheel sensors, just from what the computer expects engine acceleration to be.

Dude, with that forward biased roll couple, I don't doubt that you don't lift inside rear tire. I am going to look at all your videos tonight to see if I can see if you can discern push with that setup. How does that behave on turn-in and mid corner? Have you tested a heavier rear spring? I'm not arguing with your choice, I'm just curious.

+1 on the wheels. I just don't want to afford a setup like yours. Any thoughts on the compromise: 10" diamond racing steels at about 22#, or 9" 6UL at about 12#?

Quote:
Originally Posted by Midtenn View Post
Just need something to reliably run about 8-8.5k (yes I know there isn't power up there, just saves that extra upshift on some courses)
- GT2560
- 300whp / 250ft*lb goal
- E85
- KAAZ 1.5way or OS Giken LSD w/ a 4.1 rear.

Suspension:
- Koni Race Dampers (short term until I can bite the bullet for double adjustables)
- 600/350 spring rates
- RB 1.125" hollow front sway bar
- tubular upper control arms
- Delrin bushing equiped lower control arms (tubular later)
- 15x9 ULs w/ 275/35R15's to start with. Eventually I'll go with 15x10's.

Interior:
- Standard CSP job. Remove the rest of the AC, soft top, radio, seat belts ect. I have to check on a proposed rule that allows me to just remove the passenger side air bag without having to do the whole dash swap.
What injector do you plan on with that E85 setup? That's going to need a ton of fuel. You are around the same spot as I will be in next year, but I won't be stripping the interior parts or soft top, and I'm keeping the roll bar for track days. I'm at around 2240 right now without my fat self in there. PS and AC delete, driver airbag delete, 1/2 tank.
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Old 10-10-2009, 08:45 AM   #36
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I'll probably end up with a 750cc or 800cc injector run E85.
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Old 10-10-2009, 10:59 PM   #37
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We had our last autcross events of the season today and tomorrow. It was 25 degrees this morning with ice on the roads. No way was I taking the '94 with bald RA1's to the event.

I wound up taking the '01 with the dunlops. Still no traction with cold and rock hard tires. The high for the day was 36 degrees (normal is 61 degrees) and we froze our *** off. I'm not sure if I'm going tomorrow, I hate to bail on the last event of the season, but it would be nice to get some fall **** done and get ready for installing the roll bar in the '01 next weekend.
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Old 10-11-2009, 01:14 PM   #38
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Originally Posted by webby459 View Post
Chris, you want a strong turbo setup, lag is my friend and can be your's, too. What about tc? I was speaking with a guy last weekend that tunes AEM, he says they have a tc setup that works without wheel sensors, just from what the computer expects engine acceleration to be.
I am not going to get into the turbo vs super debate, but I think I will stick with the belt drive for now

There is a rate of acceleration based traction control in the MS-I code and supposedly some beta MS-II code that has it as well. I will be trying it sometime in the early spring.
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Originally Posted by webby459 View Post
Dude, with that forward biased roll couple, I don't doubt that you don't lift inside rear tire. I am going to look at all your videos tonight to see if I can see if you can discern push with that setup. How does that behave on turn-in and mid corner? Have you tested a heavier rear spring? I'm not arguing with your choice, I'm just curious.
You aren't going to find any video with the 1050# fronts. I only put them on for one local event before Nationals this year and the only video I have from Nationals is one run in the wet on day two. The car will push when the front tires heat cycle out even with just the 750#s on front. But with fresh tires, it seems to work pretty well at least in the limited testing I have so far. I will keep you guys posted when things warm up enough to consider any results valid.
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Originally Posted by webby459 View Post
+1 on the wheels. I just don't want to afford a setup like yours. Any thoughts on the compromise: 10" diamond racing steels at about 22#, or 9" 6UL at about 12#?
That's a power level / shock question. If you can control the heavier tire, wider is better, if you are on the edge of not enough power or shock, lighter is good.

Quote:
Originally Posted by webby459 View Post
What injector do you plan on with that E85 setup? That's going to need a ton of fuel.
I am on 750cc and 60 psi of fuel pressure and am getting close to the 80% range on race gas. I would think at least 1000cc for E-85 at national SSM power levels.

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Originally Posted by webby459 View Post
You are around the same spot as I will be in next year, but I won't be stripping the interior parts or soft top, and I'm keeping the roll bar for track days. I'm at around 2240 right now without my fat self in there. PS and AC delete, driver airbag delete, 1/2 tank.
There is some easy weight to take off in the right place for next year. Being able to replace the pop-up headlights and all the associated hardware with fixed will take 20- 30 lbs off the nose with not a lot of effort and be pretty easy to restore if you decide to.
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Old 10-11-2009, 01:43 PM   #39
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Here is an email conversation I had with Jeremy Schuster when I first started tossing around the idea of building a SSM Miata. Jeremy ran EM/SM2 for years before finally getting fed up with not having enough tire around 2005 (before the 275/35R15's A6's came out) and built the car for SPO (road racing). He's spent many years developing the car around undersized tires (245/16's and eventually ended up running 225/15's).

Quote:
Hey Jeremy,

Right now it looks like I'll be driving Jason Collet's Corvette next year. We are installed a DL1 this winter, so I'll use some data from it to determine a few of the parameters tp will base the build on. Right now my starting goals are to make the car as narrow as possible, 2150 weight, 275-300 whp, and a 70-75mph top speed in 2nd gear.

1) Turbo Choice: I've narrowed it down to the GT2560 or the GT2860. From some reading on Miataturbo.net some 99 motors with the GT2560 are putting down 300whp @ 15psi. That was with a BeGi intake manifold setup and 18x12x3 intercooler core. I know you said your old turbo was a "modified" T28 from a S15 Silvia, so how does the GT2560 compare to it?

Jeremy:
1. My turbo was (yeah, was, the compressor section got sandblasted when my air filter came off at Barber last year) a GT2560R with a T3 super60 compressor wheel and .64 A/R extrude-honed turbine. It always spooled exceptionally fast, but I attribute part of that to my intake. I tried a high-flow Garrett intercooler and lost power, so I ended up going back to the FMII intercooler. I’m now at 350 to the wheels on a dyno-dynamics, so more like 375 in dynojet terms. I’d say that the old FM IC is adequate.


2) Top Speed in 2nd: After looking at data from this years Nationals from Jason's ASP car, 70-75mph is my goal for the top of 2nd. Assuming a 8000rpm limit and a stock 5pd, a 3.9 final drive will go from 27.3mph (3000 rpm) to 72.9mph in 2nd gear. Brian and I have also tossed around the idea of using the 6spd transmission with a 4.3 read end and use 2nd and 3rd as the drive gears with about the same speeds. Is there something else I maybe missing in this equation?

3) Motor Build: When it comes to building a motor, I'm still researching what I'd need to reach 8000rpm reliably. I know the oil pump gear needs to be swapped out. Rods are probably a good idea as well. Brian and I were tossing around the idea of stock pistons and just ceramic coating them. I was thinking about an aftermarket piston, but going with a higher cr (like 10:1) for off boost performance. I'll use a 99+ head, with the first version being a port match and clean up with stonger valve springs and stock cams.

Jeremy:
2/3. I ran an 8200 rpm rev limit on a totally stock internal engine for over 3 years. That includes long periods of rev limiter at autoxes. Then I ran as high at 9200 with the built motor for a couple years. I could hit 80+ in second with the 4.10s. The six speed and 4.3s may sound like a good idea, but the 6 speed shifter sucks. Bad. I have one in the blue car now and hate it. I’d stick with the 5 speed and 4.10s, and short shift to 3rd where necessary. With the 2560 you’ll have tons of torque… I also ran a stock oil pump until this year. IMO the oil pump issue is overblown, especially for a car that won’t see the track much. If you do decide to track it, just keep the revs down below say 7500 and you’ll be fine. Stock pistons will probably be fine. You’ll give up some on-boost torque by going with higher CR. Stronger valve springs will help. I have the el-cheapo volvo springs that Randy stocker recommends on his site. Not sure they’re still available though.


4) Power Steering: I also want to reinstall the power steering to deal with the 275's. No P/S on the street tires is nothing, but I can imagine with the 275s the steering effort is going to much larger, especially in slaloms. I know you retained your power steering with an over the radiator intercooler pipe routing. This is the same way I want go with my intercooler piping to keep it as short as possible. What issues will I run into there?

Jeremy:
4. PS is highly recommended. Redline fluid helped a lot here as I used to have issues with it ‘locking’ in slaloms. Never ran a cooler until this year, so save the weight…



If there are any critical points I've missed so far, please let me know. At some point I'll start playing with the aero side of things, so that should be fun (and odd looking at the same time).

Jeremy:
7. Diff – The torsen sucks once you get into serious lateral grip. No matter how low I made the car, it still totally unloaded the inside wheel. My kaaz is holding up well, although I need to open it up and turn down the lockup ratio a bit. I’ve got it at 100%, which means my car pushes like a pig if I’m not steering with the throttle. Fun, but not as fast as it could be.
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Old 10-12-2009, 10:37 PM   #40
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Quote:
Originally Posted by Chris Swearingen View Post
There is a rate of acceleration based traction control in the MS-I code and supposedly some beta MS-II code that has it as well. I will be trying it sometime in the early spring.

That's a power level / shock question. If you can control the heavier tire, wider is better, if you are on the edge of not enough power or shock, lighter is good.

I am on 750cc and 60 psi of fuel pressure and am getting close to the 80% range on race gas. I would think at least 1000cc for E-85 at national SSM power levels.
Chris, have you messed around at all with the anti-rev in MS? I may try it out at next spring's test and tune, but it seems a little limited and the cut comes in hard. Have you found anything online on it in any forums? I looked pretty hard yesterday, but didn't find much. I wanted to find some data and feedback from people who were using it.

On the wheel question, I will consult with Shaikh and my checkbook, and see what setup makes the most ultimate sense.

What fpr and fuel pump are you using? I may work these upgrades in during my winter downtime.



Quote:
Originally Posted by Midtenn View Post
Here is an email conversation I had with Jeremy Schuster when I first started tossing around the idea of building a SSM Miata.
Midtenn, that is a ton of fantastic info from Jeremy Schuster! Thanks for sharing. That is unreal power he was getting out of these miata engines and the 2560, makes me feel like I have a setup that may be able to scale well.

Like everyone, I have a finite budget for this off-season build, and it will inevitably be a balance of compromises. My goal is to move up the pax and shoot for regional top times, and not looking like any more of a dork than I need to at the tour and div events. I'm going to give up some power for reliability and strength, and I'm going to STREET DRIVE the car and drive to events. Should be fun.

What are others doing in car prep during the off-season (if you have one!)?
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