My SCCA National budget RTR build

[MTCRX]

Originally Posted by Sam Strano

I'm glad you liked the courses.

I should study these videos. Sam, I hear you are setting one course at Nationals, is that correct?

[Sam Strano]

The East Course is mine.

[SeanRTR]

Woke up early Saturday morning and drove three hours north to a divisional event.

Happy with the results, and the car is all ready for nationals.
I also went ahead and got myself a set of Enkei RPF-1 wheels, 14.8lbs each, compared to the stock wheels at 20+lbs..... I noticed how much heavier the BFG Rival tires are compared to the stock tires, so you almost need the wheels just to offset the weight of the non-OEM tires.





I had a BS event just before this one, and tried the shocks on full stiff in the back....yeah that doesn't work at all. The car doesn't feel stable AT ALL...

Oscoda showed my shock settings that I had in Wilmington seemed to be about right, as I ended up around 1/2 turn from full stiff in the front, and 1/2 from full soft in the rear.

Results:
http://www.svr-scca.com/e107/e107_fi...coda_class.pdf

11th or something on index, 120 cars....
Video soon.

[Biggins]

I installed my rear Konis upside down too! We fixed them in the paddock the night before the Dover Tour.

But wow, my shock settings are way off from all you fast guys since yours are flipped from mine. I have the biggest bar (Hotchkis), but I've had my Konis at nearly full stiff rear and maybe 0.5-1.0 from full soft front to compensate for the big bar. I'm convinced the big bar has hurt my performance mid-corner understeer and might go back to my stock bar for the rest of the season. Do you really think a sway bar is THAT important?

I've been midpack at the two national events I've done with a codriver trophying at one, but I should have gone to Wilmington.

Have you run on Dunlops or Hankooks, or only the BFGs? Good luck at Nationals!

[SeanRTR]

Biggins, I have not run on Hankooks, or Dunlops yet.

I think the Hankooks might be a bit faster on the right day, at the right site, with the right cycles/remaining tread, and the right amount (but not too much) heat in them.

I like the Rivals because I don't have to worry about all those factors....they're great new at full depth, don't need to be shaved, don't need a ton of heat, and don't need to be watered down, or cycled in. Dunlops seem slightly faster on asphalt than Rivals, but noticably off the pace of Rivals on concrete.

I think the front bar is imporant at national style courses, where speeds are high, and transitions are fast, and abundant. I'm interested that you're running so much rear rebound, the lot that I tried it was very bumpy, so maybe that was why my car felt so terrible with that much rear rebound is dialed in. At smaller courses with tight turns and less slaloms, I could imagine the stock bar being the hot setup. 22mm Whiteline/Perrin bar on soft, or a Strano is probably going to be the prefered setup on a nationals style course.


Runs from the weekend:
Morning
[ame="http://www.youtube.com/watch?v=OEWPxD8MM9M&feature=c4-overview&list=UUZcLwIZD4WvPIyX40KOF8QA"]SVR Oscoda Great Lakes Divisional Sean Grogan 8/17/13 Morning - YouTube[/ame]
Afternoon
[ame="http://www.youtube.com/watch?v=RV2CL13Tkdk&feature=c4-overview&list=UUZcLwIZD4WvPIyX40KOF8QA"]SVR divisional Oscoda MI 8/17/13 Sean Grogan RTR - YouTube[/ame]

[autoXracer]

Did the new wheels make you faster compared to factory wheels?

[SeanRTR]

The wheels are about 5-6lbs per wheel lighter than stock....I think that's a real difference that will effect the time...but not sure it's something you'll actually feel in the drivers seat. The car feels a bit more 'responsive' at mid/low RPM acceleration where Torque is low, but this could be in my head.

All in all, 22ish pounds of mass removed from the car is a big deal, but being rotating mass is much more important, should help the acceleration, braking, as well as handling...but all so very slighly...I'd be lying if I said I FELT the car going faster, but the results were definitely favorable.

[Wepeel]

Is 31 psi still working out for the Rivals?

I'm about to pull the trigger on some Rivals - debating 225 vs 215. Everything I've read on here indicates 225 is the way to go but I do see those various RT-threads elsewhere on the internet that suggest squaring the tire to the rim may be just as fast if not faster.

Thoughts?

[autoXracer]

Originally Posted by SeanRTR

The wheels are about 5-6lbs per wheel lighter than stock....I think that's a real difference that will effect the time...but not sure it's something you'll actually feel in the drivers seat. The car feels a bit more 'responsive' at mid/low RPM acceleration where Torque is low, but this could be in my head.

All in all, 22ish pounds of mass removed from the car is a big deal, but being rotating mass is much more important, should help the acceleration, braking, as well as handling...but all so very slighly...I'd be lying if I said I FELT the car going faster, but the results were definitely favorable.

The reason I asked was because I'm still on stock wheels. I feel it's slow coming out of tight coners compared to other cars. Thanks for your input!

[SeanRTR]

Originally Posted by Wepeel

Is 31 psi still working out for the Rivals?

I'm about to pull the trigger on some Rivals - debating 225 vs 215. Everything I've read on here indicates 225 is the way to go but I do see those various RT-threads elsewhere on the internet that suggest squaring the tire to the rim may be just as fast if not faster.

Thoughts?

I'm running 32psi square, been working really well. I think the rival you can get away with 225s because the tire seems to be designed to roll a bit in the sidewall. The shoulders are beefy on the rivals, and I've never had an issue of them rolling over too much, even running just 32psi. Keep in mind the 225s will also give you 1 to 2 mph extra in second gear, very helpful for faster courses.

[mla163]

Re: pressure on Rivals.

I ran 35/34psi on mine the first time out and can't complain. I may try some lower pressures.

GRM did a test on the Rivals and found that they worked well under a range of pressures.

[SeanRTR]

Nearly ready to make the trip out to Nebraska on Monday morning.

Thanks to Gearheadhomes for help making my trip possible
www.gearheadhomes.com (search Gearhead Homes on facebook as well)

New decals applied, along with a new exhaust. I went with the HKS Legamax Spec-L due to its light weight construction. This exhaust should be somewhere around 10-15lbs lighter than stock. Low weight is this cars best attribute, so decided I might as well play to that strenght. Other competitors at the national level are using a muffler delete system, so this was the best option for me since I drive the car daily as the HKS Legamax Spec L exhaust delivers a good exhaust note, with no drone...and it looks fantastic with the carbon fiber tips.

I also went with a fresh oil change into the Joe Gibbs Driven FR20 synthetic 5w20 street oil. Driven oil uses a higher zinc content to extract every bit of horsepower possible, while maintaining all other required additives necessary for a street oil.




Stay tuned for more updates.....

[aCab]

Where are the updates?

[SeanRTR]

Originally Posted by aCab

Where are the updates?

Slacked on this, I appologize.

The car was very, very loose at nationals. Turns out the BFG Rivals were good all year long, but terrible at the grippy concrete in Lincoln. The problem seemed to be the additional rubber laid down on the surface, which seemed to make the other street tires a bit faster (Dunlops mainly) and somehow made the BFG's actually get slower.... I tried to do a few things to keep the rear end planted, lower rear tire pressure, etc etc...but all of this seemed to be a band aid at best, and was a compromise in other areas of the course. I managed to take one of the final trophy spots at nationals, which I'm semi happy with given being on the wrong tires. I think I was 13th of 57 cars in RTR. It's my first trophy at the big dance, after coming up 1 spot short last in my FSP Neon, and running mid pack my first ever trip in 2007 in the same Neon in STS (Knife to a gunfight).

Other than the tires, the car worked great....

The HKS Legamax Spec L exhaust was fantastic for the long drive (14 hours) to Lincoln. Sounding nearly as quiet as stock on cruising speeds, but a good tone when you got on it and hit the high RPM's. The brake pads worked fantastic at nationals, as I really didn't run into ICE mode like I have been locally, but I'm not sure this is a brake pad compound issue at all. The 22mm front Perrin bar on soft seems to be the perfect balance for the FR-S on street tires, as my car was very stable in the slaloms, and didn't seem to push on the slow speed tight corners on day 2's course. Can't say I feel any difference in the Joe Gibbs Oil, but I have no complaints, and the car seems to be pulling pretty well after 20k+ miles with the Cosworth air filter, and HKS exhaust. I've since done a second oil change with the Joe Gibbs FR20 oil, but the car is currently parked due to snow and BFG Rivals with 0 tread.

Next season I'm going to try a staggered tire setup (size and compound), and see how it does in the new C-Street class. I'll be at Both Wilmington national events, and if those go well, I'll make the trip to nationals. Even if our Pax sucks, I'm looking forward to competing against other twins within the class.