SCCA STR 370z Progress Thread.... It can be done!

[Chuck33079]

Sounds like a plan.

[synolimit]

Originally Posted by chknhawk

So what do you recommend for spring rates and would you recommend no sway in the back. I would lile to put a whiteline up front.

Sent from my SAMSUNG-SGH-I337 using Xparent Skyblue Tapatalk 2

Buy my WL

[MIKE_STR]

Ok, so I swapped out my 18k front springs for 14k and my 14k rear springs for 12k.

Re-installed my whiteline sway bar in the rear. Moved whiteline front bar to full stiff.

Now... I need to adjust the perches as this lowered my car about 2"! I also need to buy some new tires. Tried to order a set of federal RSR's... Cause they were ultra cheap. I received an email today saying they were out of stock...

Back to the drawing board!

[PharmDZ]

How did you like your RS3's Mike? I have a set of 275 square for the stock sport rims I need to put on soon (33k miles on the re050's is more than enough) that I'm debating autocrossing on. Other options are my r888's I use mainly for HPDE and a set of big ole Hoosier A6's I was hoping to save for when I have a bit more seat time. 18's are a tough size for tires for this car! My enkeis with the toyo r888's take a 275/40 to keep near stock diameter. Odd sizing

[03threefiftyz]

Once Sept hits, I'll probably have 10-12 sets of 315 and 335 A6's for sale, FWIW. Most will have 12-30 runs on them. They'll be for sale at substantially less than sticker tires cost.

[MIKE_STR]

Originally Posted by PharmDZ

How did you like your RS3's Mike? I have a set of 275 square for the stock sport rims I need to put on soon (33k miles on the re050's is more than enough) that I'm debating autocrossing on. Other options are my r888's I use mainly for HPDE and a set of big ole Hoosier A6's I was hoping to save for when I have a bit more seat time. 18's are a tough size for tires for this car! My enkeis with the toyo r888's take a 275/40 to keep near stock diameter. Odd sizing

I liked the RS3's just fine. Great tire that handles heat well.

I don't like the new price gouging of the RS3's... up $200 a set...

I remember the good ole days when RS3's were $500 a set.

[stuy486]

Originally Posted by MIKE_STR

I liked the RS3's just fine. Great tire that handles heat well.

I don't like the new price gouging of the RS3's... up $200 a set...

I remember the good ole days when RS3's were $500 a set.

Hey Mike, this is Jeff (Blue CS 370z, we talked at El Toro)

I just checked TireRack and noticed that they V2 RS3s seem to have gone down in price from when they originally went on sale a few months ago. My 275/35/19s went down about $44 a tire ($356->$312), so now they're priced about the same as the 200TW V1 RS3s (before they went on closeout). 255/35/18s are $227 a tire.

[MIKE_STR]

Originally Posted by stuy486

Hey Mike, this is Jeff (Blue CS 370z, we talked at El Toro)

I just checked TireRack and noticed that they V2 RS3s seem to have gone down in price from when they originally went on sale a few months ago. My 275/35/19s went down about $44 a tire ($356->$312), so now they're priced about the same as the 200TW V1 RS3s (before they went on closeout). 255/35/18s are $227 a tire.

Good to know. Hopefully, the car will just be moved to STU for next season and I can invest in some 285/35's.

Btw Jeff, do you ever run into ABS lock up with your Z? What pads are you using?

[stuy486]

Originally Posted by MIKE_STR

Good to know. Hopefully, the car will just be moved to STU for next season and I can invest in some 285/35's.

Btw Jeff, do you ever run into ABS lock up with your Z? What pads are you using?

Stock pads. I run into what I'm pretty sure is ice mode a lot on asphalt, and it's pretty miserable when it happens, but I haven't had problems with it on the concrete at el toro.

[j-rho]

Hi Mike,
How have things been going? Have to admit at the Farmington Pro in 2013 (was there in my '67 Camaro in STX) I remember seeing your car and thinking to myself "Hmm, a 370 would be fun in STR" - year and a half later, I have one, and am looking at STR prep.

Some questions I haven't seen clearly answered elsewhere, though there's still more research to do-

• Kinetix front upper arms can get enough camber with a little modification?
• Are any rear arms needed to get camber where we want it once lowered (something like -2 to -2.5)?
• Does the Uprev Osiris tuning capability close the throttles faster on lift? With the stock computer it seems to wait half a second to do so when you lift, which as a right-foot-braker, messes things up sometimes.
• What parts are needed to run 2.5" diameter rear springs with ride height adjustability in the rear? And what length spring assuming rates in the 700-850 range as a starting point?
• Is the 1.5-way OS Giken "the way to go" or has anyone found benefit to another option - either 2-way, 1-way, or another brand?
• Any "must do" bushings besides the rear diff?

Not trying to muck up your thread, just thinking we can keep this the place people go for 370Z-specific STR info.

Thanks!!!

[03threefiftyz]

Different Mike, but I'll take an initial stab....fWIW, I've been pretty happy with the Cusco RS 1.5 I have in the BSP car, but it took some finangling to get right. At least with the 350z, we have all had to modify the Kinetix arms (thinner jam nuts and grinding down the thread portion of the A-arm to get enough camber). Even at my ride height, I got more camber out of offset bushings than the Kinetix arms as they were shipped. You can get the rear spring perches from BC, Stance, Megan, etc for not much money. I have used the Megan for 3-4 years now without issue (and so has Peters in STR/STU). You can tune throttle latency and saturation with UPREV. Can't comment on the bushings for a 370, but the compression rod and front lower control arm bushings are a once a year replacement if you use stock on a 350z.

[MIKE_STR]

Originally Posted by j-rho

Hi Mike,
How have things been going? Have to admit at the Farmington Pro in 2013 (was there in my '67 Camaro in STX) I remember seeing your car and thinking to myself "Hmm, a 370 would be fun in STR" - year and a half later, I have one, and am looking at STR prep.

Some questions I haven't seen clearly answered elsewhere, though there's still more research to do-

• Kinetix front upper arms can get enough camber with a little modification?
• Are any rear arms needed to get camber where we want it once lowered (something like -2 to -2.5)?
• Does the Uprev Osiris tuning capability close the throttles faster on lift? With the stock computer it seems to wait half a second to do so when you lift, which as a right-foot-braker, messes things up sometimes.
• What parts are needed to run 2.5" diameter rear springs with ride height adjustability in the rear? And what length spring assuming rates in the 700-850 range as a starting point?
• Is the 1.5-way OS Giken "the way to go" or has anyone found benefit to another option - either 2-way, 1-way, or another brand?
• Any "must do" bushings besides the rear diff?

Not trying to muck up your thread, just thinking we can keep this the place people go for 370Z-specific STR info.

Thanks!!!

Very cool. Wish I would have known someone was looking to build one... As mine is now for sale mostly prepped. (Baby on the way...)

Anyway, race today... But I've learned a lot this year and can certainly save you some time. I'll try and get on tonight to answer all your questions.

[MIKE_STR]

Originally Posted by j-rho

Hi Mike,
How have things been going? Have to admit at the Farmington Pro in 2013 (was there in my '67 Camaro in STX) I remember seeing your car and thinking to myself "Hmm, a 370 would be fun in STR" - year and a half later, I have one, and am looking at STR prep.

Some questions I haven't seen clearly answered elsewhere, though there's still more research to do-

• Kinetix front upper arms can get enough camber with a little modification? Yes. I modified mine (cut them) to get a little over -3 camber in the front.
• Are any rear arms needed to get camber where we want it once lowered (something like -2 to -2.5)? maybe not. Just an FYI, I started with about -2.5 rear camber and have reduced that dramatically. The car just can't put power down with that much rear camber.
• Does the Uprev Osiris tuning capability close the throttles faster on lift? With the stock computer it seems to wait half a second to do so when you lift, which as a right-foot-braker, messes things up sometimes. it's funny you mention this... I just noticed it the other day. I had my car tuned already down at specialty Z. I didn't even think to ask him about it when he adjusted the throttle mapping. It just occurred to me literally a week ago that the car would keep the throttle bodies onen for nearly a second after lifting throttle. Definitely doesn't help rotation on lift like I like.
• What parts are needed to run 2.5" diameter rear springs with ride height adjustability in the rear? And what length spring assuming rates in the 700-850 range as a starting point?BC racing supplied the adapters / collars needed to run the 2.5 inch springs that I have. I've been very impressed with the ER series that they custom Valved for me.
• Is the 1.5-way OS Giken "the way to go" or has anyone found benefit to another option - either 2-way, 1-way, or another brand?i use a Cusco RS and like it. It's currently set at 60%
• Any "must do" bushings besides the rear diff? not really. Sure, I'd like to do the front lower control arm / rear bushings... But no one makes any that aren't spherical.

Not trying to muck up your thread, just thinking we can keep this the place people go for 370Z-specific STR info


Thanks!!!

Maybe just sell your stocker and buy mine.. I'd cut you a hell of a deal.

[j-rho]

Thanks for the info Mike and Mike! Could either of you post a link to the rear spring stuff you got? The Megan and other parts I find for the 370 all seem to want to work with their own wacky springs, not the normal 2.5" stuff.

For the Uprev, do I have to buy a copy? Or if I take my car to a tuner who already has the software, can he just use it on my car?

Since we have to run cats, is there much gain in catted longtube headers vs. stock manifolds + berk HFC? What's the best dynos you guys have seen of ~ST prep 370's?

For those not familiar with the ST rules, we are allowed to do:
Headers (but must maintain cats in roughly the stock location - cats can be aftermarket)
Cat-back exhaust
Cold air intake (up to throttle body, have to keep stock MAF sensors)
ECU tune (up to 100 octane fuel, no e85)
Crank and accessory pulleys

[03threefiftyz]

You have to call Megan, BC, Stance, etc....they don't list them separately. At least for the 350z....they use 2.5" springs. The popularity of "true" coilovers has left all of those guys with all sorts of rear spring perches on the shelf. You will want to find an UPREV tuner (there are a bunch), but you can also buy the tuner version for more money.