S197 BOSS 302 Race Car Build Thread Build Thread

[ArizonaBOSS]

Drew,

What spring rates did you go with? I plan on 800lbs in the front and 250lbs in the rear. BTW I have talk to AI guys and they all suggested the remote reservoirs because of heat. Did you and Jason talk about heat in the fluid of the shocks/struts? Thanks

800/275. Easy enough to swap rear springs if a different rate is desired, too.

I did talk to Jason about all that, we agreed that for 30-45 minute sprints that I run 99% of the time that damper fade shouldn't be an issue.
If it were 1.5-2 hour enduros, then yes that would come into play.
Since the MCSeseses are modular, I can upgrade to remote reservoirs later (during a rebuild, for example) if I desire. So this was a good way to get more damper performance and not (completely) shatter my bank account. Also at least I can see how the internal doubles work and THEN make a decision if I need something more after that, and not have to pay for it all up-front.

 

[twistedneck]

800/275. Easy enough to swap rear springs if a different rate is desired, too.

I did talk to Jason about all that, we agreed that for 30-45 minute sprints that I run 99% of the time that damper fade shouldn't be an issue.
If it were 1.5-2 hour enduros, then yes that would come into play.
Since the MCSeseses are modular, I can upgrade to remote reservoirs later (during a rebuild, for example) if I desire. So this was a good way to get more damper performance and not (completely) shatter my bank account. Also at least I can see how the internal doubles work and THEN make a decision if I need something more after that, and not have to pay for it all up-front.

i was seconds away from ordering the MCS setup from Vorshlag MCS but pulled trigger on Cortex / JRi. Both are top notich looking forward to seeing pics of yours installed. Also, i'm weighing the cortex setup front and rear (no reservoirs) so we can compare. i'll post the weights tonight.

 

[DGRacing]

Drew,
Awesome post a page back with the update, pics, videos, etc. Good stuff.

How do you like the 275lb rear spring (what damper setting too)? I'm about to put 800's on the front with 400 rears (@ 700/400 now). Currently at 4/10 clicks all around for compression/rebound.

 

[ArizonaBOSS]

CorteX/JRi was also on my list but I wanted to try something a little different. Also it seems the JRi adjustments both rebound adjustments instead of separate compression/rebound adjustments from what I've read here.
I will get some weights of the dampers when they arrive in 4-6 weeks! I am guessing the rears should be lighter since they are aluminum-bodied, but the fronts will probably be similar because they are steel. I guess we'll find out!

Darren: Thanks! Like I noted above in this post, the spring and damper package won't arrive for another 4-6 weeks so I have no performance feedback thus far on that specific package.
What I CAN tell you is currently I run a 515/230.
Originally the setup was 515/400 and that was not good for putting the power down on corner exit. The car would just blow the tires off even with relo brackets.
The 230 spring really had a positive effect for me compared to the 400. I think the 400 rear might be OK for a "no rear swaybar" application.

We decided on 800/275 based on the testing done on Vorshlag's TT car with aero. I think 275 will be as high as I go, if I need to go lower, that is an easy and inexpensive change.

FWIW, my BMW racer buddies say that MCS is the hot shiznit with their crowd right now.

 

[twistedneck]

CorteX/JRi was also on my list but I wanted to try something a little different. Also it seems the JRi adjustments both rebound adjustments instead of separate compression/rebound adjustments from what I've read here.
I will get some weights of the dampers when they arrive in 4-6 weeks! I am guessing the rears should be lighter since they are aluminum-bodied, but the fronts will probably be similar because they are steel. I guess we'll find out!

Darren: Thanks! Like I noted above in this post, the spring and damper package won't arrive for another 4-6 weeks so I have no performance feedback thus far on that specific package.
What I CAN tell you is currently I run a 515/230.
Originally the setup was 515/400 and that was not good for putting the power down on corner exit. The car would just blow the tires off even with relo brackets.
The 230 spring really had a positive effect for me compared to the 400. I think the 400 rear might be OK for a "no rear swaybar" application.

We decided on 800/275 based on the testing done on Vorshlag's TT car with aero. I think 275 will be as high as I go, if I need to go lower, that is an easy and inexpensive change.

FWIW, my BMW racer buddies say that MCS is the hot shiznit with their crowd right now.

Makes me wonder if the 500/300 setup will hook coming out of corners with my Cortex setup.

FYI - the Cortex / Jri rears are aluminum body, just the front one is steel.

 

[ArizonaBOSS]

Makes me wonder if the 500/300 setup will hook coming out of corners with my Cortex setup.

FYI - the Cortex / Jri rears are aluminum body, just the front one is steel.

I think you will be OK. It will depend on your driving style, as well. But you will have a higher quality damper than the KW/Roush stuff I'm running now so the motion may be much better controlled than what I've dealt with so far.

 

[VoodooBoss]

I thought the front JRi inserts were aluminum? They slide into the mount which is steel.

 

[twistedneck]

I thought the front JRi inserts were aluminum? They slide into the mount which is steel.

Hmm.. let me go look again i'll try a magnet after work.

 

[Grant 302]

Hmm.. let me go look again i'll try a magnet after work.

Rick is right. the magnet will stick to the (silver) painted parts that are steel.

Still in for all the updates and racecar goodness. 8)

 

[DGRacing]

What I CAN tell you is currently I run a 515/230.
Originally the setup was 515/400 and that was not good for putting the power down on corner exit. The car would just blow the tires off even with relo brackets.

That is actionable intelligence right there. I'm gonna try a spring swap in the rear. Thanks!!

 

[twistedneck]

I thought the front JRi inserts were aluminum? They slide into the mount which is steel.

Got out the strong mini magnets and determined the body is indeed aluminum on the Cortex JRi rear SA coilover.

Weights using fish scale (assume +/- 1.5lbs)
Front: 18lbs
Rear: 6.75lbs

That does not include all mounting hardware like bolts and brackets.

 

[twistedneck]

CorteX/JRi was also on my list but I wanted to try something a little different. Also it seems the JRi adjustments both rebound adjustments instead of separate compression/rebound adjustments from what I've read here.
I will get some weights of the dampers when they arrive in 4-6 weeks! I am guessing the rears should be lighter since they are aluminum-bodied, but the fronts will probably be similar because they are steel. I guess we'll find out!

Darren: Thanks! Like I noted above in this post, the spring and damper package won't arrive for another 4-6 weeks so I have no performance feedback thus far on that specific package.
What I CAN tell you is currently I run a 515/230.
Originally the setup was 515/400 and that was not good for putting the power down on corner exit. The car would just blow the tires off even with relo brackets.
The 230 spring really had a positive effect for me compared to the 400. I think the 400 rear might be OK for a "no rear swaybar" application.

We decided on 800/275 based on the testing done on Vorshlag's TT car with aero. I think 275 will be as high as I go, if I need to go lower, that is an easy and inexpensive change.

FWIW, my BMW racer buddies say that MCS is the hot shiznit with their crowd right now.

Are you using the 18mm rear sway bar or smaller still?

 

[ArizonaBOSS]

I have a 22mm adjustable rear bar.

 

[ArizonaBOSS]

Got my latest set of wheels in. Enkei PF01s in 18x10.5 38mm offset.

I have heard that these wheels eventually get cracks in the spokes after a few years of use but considering these are brand new I should be fine for a few seasons and then retire them. Tough to beat the quality, width, and weight for the price. I plan on getting a second set in April/May to ensure I have two sets of 10.5 wheels for NASA Nationals.

Weighed in at 21.6lbs (subtractive method) on my scale.

Anyways, they look great and I can't wait to get some 315mm R7s mounted on them later this month!

 

[Berol]

Love the color in that second shot.

 

[Flyboygsxr]

Are you running the 18x10.5 front and rear? I have the same wheels but I run staggered…18x9.5 front and 10.5 rear. I was always curious if they made a larger offset that could fit on the front

Got my latest set of wheels in. Enkei PF01s in 18x10.5 38mm offset.

I have heard that these wheels eventually get cracks in the spokes after a few years of use but considering these are brand new I should be fine for a few seasons and then retire them. Tough to beat the quality, width, and weight for the price. I plan on getting a second set in April/May to ensure I have two sets of 10.5 wheels for NASA Nationals.

Weighed in at 21.6lbs (subtractive method) on my scale.

Anyways, they look great and I can't wait to get some 315mm R7s mounted on them later this month!

 

[ArizonaBOSS]

Yes, will be both front and rear. For more info search "315s on all four corners" here on BMO.

 

[13Boss#3328]

Are you running the 18x10.5 front and rear? I have the same wheels but I run staggered…18x9.5 front and 10.5 rear. I was always curious if they made a larger offset that could fit on the front

I run the same exact wheels (silver) all four corners

 

[ArizonaBOSS]

I run the same exact wheels (silver) all four corners

 

[ArizonaBOSS]

OK so update!

This weekend a friend and I went out to Willow Springs International Raceway to mix it up with some of the guys from NASA SoCal. This was our first time to the track and it is FAST! Very intimidating if you think about going off track at the speeds you can carry here.

With the R7 Hoosiers on the car, my best time was a 1:31 flat. The Vette guys in my race group (on Hoosier A6s) were running 1:25s and 1:26s mostly. So my job for the weekend was just to survive, not have any contact, and book two races towards my 5-race minimum to qualify for NASA nationals. Mission accomplished.
We spent the weekend getting our asses handed to us, but it was a good learning experience and shows we still have a lot to learn about how to drive fast This was a track that rewards bravery but I don't think we had enough.
The 315 Hoosiers definitely helped, however. The car felt very stable and the turn-in was sharper than ever before.

This weekend I'll be racing some familiar competitors at a familiar track, so I hope to be at the top of the heap this time. But there are some big steps to be made before we get to Laguna Seca for Nationals in July. A7s and the MCS dampers I have on the way should help with that. Also I have poly bushings for the FLCAs as well as Howe ball joint upgrades for the FLCAs from Watson sitting in my garage right now. Other than that, just need to drive better!

Here are a couple pictures and a video from Willow Springs.








Here is a video from Qualifying, where I put down my best lap. I spent the first couple laps just warming up the tires gradually since they were brand new and I didn't want to shock them. I didn't take care to heat cycle them properly, however. We'll see how long they last this way.

https://www.youtube.com/watch?v=SAfA-0IFUBs

Also we rolled the fenders when I got back to Phoenix to help with the very slight tire rubs w/ the 315 setup and these wheels. Should be good to go now!