Dmod Project
Aren D. 27 Jan 2020
What can I say I love my little CRX, and at first it was supposed to be a prepared build but I may have overstepped a few rules so legally my car is a DM car, instead of going backwards and trying to repair the car to a state of XP or EP I am going forward with a bad ass DM CRX.
About this project,
This will not be a ground up build instead I will only be doing modifications or changes that can be accomplished between races, I will only start updates/projects after I have acquired all the supplies and/or parts required. I plan to attend every local event this year and possibly some pro-solo events.
Okay for now I will be a FWD with a sub 1.8l motor and a "stock TUB". Minimum weight for this class/configuration is 1245LBS with Driver, I weigh 190, So we are looking to get the CRX down to 1055LBS.
The good news is that for XP the car weight was supposed to be 1440lbs, and my car currently weights 1230.5 with out driver or a front bumper, but with 14"wheels and street tires that are 4.6lbs more weight than my 13" race wheels/tires.
Also bad news is that 1230.5 is without ballast... and without ballast my car corner weights without driver are as follows:
FL-416.1 FR-418.2
RL-195.1 RR-201.1
You can do the math on that F/R weight ratio, its poor.
For XP I was planning to ballast the car up... but I never did, and I drove it for 3 events pretty much like that it was extremely loosley goosey in the back.
Aren D. 27 Jan 2020
DSC_0004 by Aren D, on Flickr
DSC_0005 by Aren D, on Flickr
In order to install, I have to drop the sub-frame mostly our of the car. My under tray that wasn't doing me any favors because I never finished my front spliter project was in the way and had to be terminated.
DSC_0006 by Aren D, on Flickr
DSC_0007 by Aren D, on Flickr
I didn't get the rear out so that should probably make a racket on the race Saturday.
DSC_0008 by Aren D, on Flickr
You may notice a rear ARB, for now I am just doing some testing it wont be on for the next race, as a matter of fact I promised that bar to a member.
Old School REX 30 Jan 2020
I've followed your build up on this car since it was a true street car. That will not change with your new goal to switch to DM. Looking forward to watching the progress and definitely think it's a good idea to do small projects between races! That way you're still out enjoying the car as often as possible.
Not related to a real race build in any way.... but I installed a teg front sway bar when I went B swap to help with the extra weight of the motor. I very much liked the results. Currently my full weight streetcar handles very neutral.
Aren D. 04 Feb 2020
I've followed your build up on this car since it was a true street car. That will not change with your new goal to switch to DM. Looking forward to watching the progress and definitely think it's a good idea to do small projects between races! That way you're still out enjoying the car as often as possible.
Not related to a real race build in any way.... but I installed a teg front sway bar when I went B swap to help with the extra weight of the motor. I very much liked the results. Currently my full weight streetcar handles very neutral.
Thanks man, enjoy the show.
Here is the rear sway-bar set up I was testing with it, its still to soft I am going to lock the axle.
Beefy rodend right? lol about 1.5 lbs.
So the integra bar helped along with the ST rear bar, but the car still has excessive movement and I can just picture in my head, the pretty little picture I drew of my car in a turn rolling nicely to my static camber setting, going in to the trash can as I was scrambling about. Forcing the car to drive around the course is not what I remember at all when this was a street car, in SMF it was WAY faster.
VIDEO:
BTOD_Trim by Aren D, on Flickr
What I feel is going on is that I have simply lowered my car too much. The huge polar movement between the front RC and the front CG is just overwhelming my roll resistances up front. At the same time my camber curve is, well the worst ever.
I am now in the middle of the lovely task of re-indexing the torsion bars. I am going to jack this bitch up for the next race probably putting the outer lower ball joint 1" below the torsion bar center. Brand new alignment numbers all around as well TBD.
I'll report back! Ha the car is going to have some massive fender gap guys.
Aren D. 07 Feb 2020
Hi guys I have all new settings for the event Sunday!
Here are the numbers:
Front Camber: -2.5*
Front Caster: +6*
Front Toe: 1/16" total toe out
Rear all zero
I have adjusted the front LCA so that the outboard ball joint is 1 inch lower than the center of the torsion bar. This, according to my measurements gives me a new front Roll center of 3.71 above ground.
20200207 Settings by Aren D, on Flickr
This is with 13X10 wheels and 255/40/13 tires and the camber noted above.
I have reset the rear roll center to 5" above ground, this is more of a guess.
Set backs:
I had to remove my shock extension mounts/camber plates and put my old RPR base plates on to have enough drop travel... I Know, I am basically the only guy saying my shocks are too short! but they are for these settings.
For the rear I do not have enough drop travel with the RSX Konis so I am going to see if these Miata Koni front shocks will do the trick of the rear:
The same adapters needed for the RSX shocks will be required for the Miata shocks here is the adapter drawing:
Lower Bushing by Aren D, on Flickr
Front Pic:
Rear Pic W/ RSX koni:
Bonus pics to spice up Thread:
received_208160870362544 by Aren D, on Flickr
received_1562085167291115 by Aren D, on Flickr
received_1707125792745608 by Aren D, on Flickr
Anyway I am going to try to get the Miata shocks on tomorrow hopefully the drop will be there.
Aren D. 08 Feb 2020
Old School REX 10 Feb 2020
Hopefully the ride height change will give you the results you're after. Is it possible that you just changed the overall feel of the car by switching away from the rear panhard bar setup?
Aren D. 10 Feb 2020
I will keep updating my build with what not to do.