My autocross FD SM2 build up
 

I thought I would share with the forums my conversion from running SCCA Solo ASP to SM2.

http://www.rotarycarclub.com/showthread.php?t=243


It is a work in progress that will be updated as I have time.

Thanks,
Dan

Very nice engine choices. ;)

Thanks, it is different than what most would build and I received a lot of "what the hell are you thinking" comments when I shared my thoughts. Only two people seemed to understand what I was really after, Ari from RP and Rob from Pineapple. Both were very supportive during my research phase of the build.

I should also thank Erik (streldoc) and Andy (Amrx7) for all the information they have shared with me on the setup of their cars. You won’t find two nicer people in the RX7 community.

Dan

Interesting engine work.

Regarding the porting, I had my engine rebuilt by Rob as well, with the exact same goals in mind - low end torque and spooling up the turbo as soon as possible.

Though my car is still 'under construction' and hasn't been raced yet with the new engine, the low end torque is surprisingly good. With 6-8 lbs of boost during break in I was seeing full boost on the turbo (TO4S .82 AR hotside) by 5k RPM.

I didn't go as far with the motor mods as you have though, it is still using all FD internals.

I did go for some other mods though, heavy duty coolant seals, and oil passage mods.

Can't wait to race it!

I guess I should have been clearer; I'm doing the porting and building of the motor. The only thing I didn't do is the balancing.

Rob was asking me for help finding a IDA down draft manifold and some how we got in a discussion about porting. That is when I bounced my build ideas off him and he offered his suggestions. I got a pretty good laugh when he told me to "Think like air" but I understood what he meant.

I'm with you, can't wait to get my car back together and hit the races.

Dan

Dan, I think you've made some very good choices and the car should be a rocket off the corner. It will be interesting to see a full torque turve all the way to redline with the 99 specs. However, I do love the simplicity of my single setup from a strictly maintenance point of view.

One note, you mentioned alot of use of 99 parts. I'd be careful that those are allowable mods covered by SM rules since you can't update/backdate to them legally. I think everything you listed was fine, but not sure about the bumper support.

-Andy

Hey Andy,
Thanks for kind words.

I think I could make an argument under section P that the rebar is to facilitate an allowed change as it is the lower attachment point of the bumper and does not weigh less than the stock rebar. Functionally it servers the same purpose and is not an intrinsic performance enhancement. What do you think?

One part I can't find a rule on is side skirts, are they allowed?

Thanks,
Dan

Updated the original link with pictures of the porting, tire fitment, gauges and carputer. Also wrote a little bit about the porting.

Thanks,
Dan

Looks good Dan.
SM2 should be fun. I am always up in the air about SM2 or ASP. I just jump back and forth at the moment since I am not even fully prepped to ASP rules. If I want to race more people and have fun=SM2 and if I want to chase pax=ASP.
I am with you on wanting to change some body parts but can't under SP rule set. I have always wanted to put the hood vents from a Jaguar XKR Supercharged into an FD hood but can't unless I want 2 hoods to still race in ASP.
Having the 4.77s should just dig you out of the corners (another reason to go SM2). I have been wanting to try and find some 15X10s or 10.5s with the 275/35 hoosiers that could fit over the FD suspension just to fix the gearing problem in ASP.
While the engine issue is being discussed and Andy is reading this... Are the Racing Beat aluminum engine plates an SM2 legal mod? My guess is no and there is no way I would spend the money but bench racing is always fun. With the season about to start again you can tell I have crazy ideas bouncing around my head.

I have and will be keeping an eye on your results. Hopefully I can race you at a GASS event or some other event between our regions. I am doing the baby thing at the moment so I have not hit as many events lately.

Also +1 on thanking Erik and Andy. They help out a lot. Without Andy I would have had a hard time getting through tech at my first Nationals at Forbes.

Jeff

Helpfull thread.

very cool

Dan,

The next paragraph of P gives you more examples of the modification of parts for the allowable mod. It doesn't suggest replacement of parts not already covered elsewhere in the rules. From a strict interpretation, I'd think you'd be better off modifying the stock reinforcement (we're talking about the big yellow fiberglass piece,right?) to work with your front end, even if it means hacking it up.

That said, if the weight is the same I don't think anyone will give you grief. We have enough issues with participation without driving people away over nit picky stuff.

-Andy

I love the fact that your using the 9.7 compression rotors for improved throttle response. Are you going to run the twins seq? I've always been curious as to how much faster the twins would spool with higher compression rotors.

Yes, 99 twins to start with, may move to a single if I don't meet my HP expectations.


Dan

Yes, mine is not yellow it is black but I have seen them yellow. Hacking up the stock one would make it lighter than the replacement. hmmm... maybe I can unbolt the lower loop and attach it to the oem and save a few pounds.

Dan

Updated write up to include links to parts used in build up.

Dan

fwiw, i just bought another used bumper reinforcement to replaced my original one that had been cut up to fit a FMIC. My original one was black/greyish. The other one is yellowish.

Yeah, same color here, but I have seen the yellow one on some cars. The 99 is white ABS plastic with a black lower hoop.

Dan

If I raced with SCCA, I'd be in XP.
Do you know if at last nationals the SM2 guys (Andy and Erik) beat the XP times?

SM2 was the only heat that ran in the rain on the first day so overall they didn't beat XP times. If you look at just second day results, yes SM2 was faster than XP by close to 1 second.

Dan

Added a couple pictures of the rear wing being installed.


Dan

Posted some information on using RX8 internals in a 13b-rew here:

http://www.rotarycarclub.com/showthread.php?t=847

Dan

Updated the thread with pictures of the engine being built.

http://www.rotarycarclub.com/showthread.php?t=243

Dan

unfortunately it wont let me view your rotaryclub thread without having a membership :(

Updated the thread with pictures of the completed engine and a list of mods required to use the Xcessive LIM with stock or 99 twins.

Dan

Motor is installed in the car and is almost ready to fire up. Added quite a few pictures of the build up and misc parts installed.

Dan

The build has come along nicely. How soon until she's ready for SM2 action?

If we don't run into any issues at startup another week or so. Our next local event is 5/11 so that gives me about 2 weeks to get everything sorted out.

Dan

very nice car. good luck with it.

Yet another update with a bunch more pictures and a write up at the end about the first start.


Dan

Added pictures of the wing fabrication and inside wiring. Also a small right up at the end of the thread.

Build thread

Dan

Added pictures and specs of the alignment and corner balancing.

Dan

Saw the car in action this weekend, good job.

Thanks, she is still de-tuned right now and I need to install the Kaaz and 4.77 but I'm pretty happy overall with the way she is running.

Now I need to work on the biggest limiting factor.... driver :)

Dan

So... when will you have something to topple Erik's car? ;)

:D, Was nice meeting you Sunday.

Added a video and some action pictures from the Atlanta National tour.

Dan

Very nice and informative write-up! I autocross in SM2. My car is starting to show early signs of a bad coolant seal(s) and your build-up has got me interested. How is the low-end/boost response now with the higher compression rotors? I too have the 99 twins, however I feel as though the 93-95 twins had higher torque at lower boost pressures compared to the 99s. The 99s feel much better at 10-15psi.

I think it rude to ask people how much they pay for things, but could you perhaps PM me with how much I could *expect* to pay for a similar motor setup???

Thank-you!

Spool up is insane; I go from 60 ft lbs to 200 ft lbs in a 500rpm range, peaking at 225 ft lbs on the first turbo at 3200 rpm at 12 psi of boost. I estimate that I will be getting close to 260 ft lbs on the first turbo when we turn up the boost.

Dan

chadwick, i still can't see your build thread without logging in. :(


hopefully we'll see you at the next nashville autox :)

Dan,

I used to peak at about 250ft-lbs on my first turbo when it was bone stock. It would drop off to about 225 before the transition point, then spike to 300+ after the transition. This was at about 15psi.

I didn't figure out I had the sticking solenoid issue where it would blow off boost when going back down to just the primary turbo (I'm pretty sure you have the fixed). When it *didn't* have that issue, the car was a rocket off the corners with the 4.77 gears.

-Andy

I know exactly what you are talking about; I changed out the turbo control solenoid and still had the same problem. We added a Home Depot bleeder valve to the pressure tank to keep it below 10psi and problem solved. Max-Q is reporting anywhere from .75 to a high of .98 g’s of acceleration coming out of corners and that is still with the 4.10 ring and pinion. I can’t wait to install the 4.77. I had one log report 1.32 g’s but I’m sure it was wrong as I also think the .98 is suspect, but I do consistently get readings in the high .7’s to mid .8’s.

Dan

hey very nice car man! I'm just getting into autocross, i'm in SM2 also. I'm still getting used to the car as it is but its a lot of fun. im still on stock R1 suspension but after a few more events of getting used to the stock suspension i'm looking to get konis on my car and some new springs. just need to figure out what rates i'm gonna get. keep up the good work!:) :icon_tup:

Dan, you put the Kaaz and 4.77 in yet?

Nope, still sitting on the bench. Been out of town the last 3 weeks. Racing in Indiana this weekend and Ohio next so it will still be a few weeks before I have time to install it.

Dan

Been awhile since I posted an update on here. Added some action pictures after the the Kaaz and 4.77 were installed. What a great upgrade.

Build thread


Dan

URL doesn't work!

https://www.rx7club.com/************...read.php?t=243

Well I guess they are still blocking links to the Rotary Car Club . Com but if you click on the quote button you can copy and paste the link in your browser.

Dan

^^^

Catually you can't the asterisks show up there too... but I'll search for ya over at RCC.

/sigh...., they just changed that too, I did it to post the first link and now I also see my signature is broken.


Here is one of the pictures:

http://www.tweakit.com/rx7/rx7trscca1.jpg

Here is the in car video from the sameday that picture was shot:

http://www.youtube.com/watch?v=lVNW1l4e3P8&fmt=18


Dan