I want to get started in Time Trials in my GT350. Thoughts on my particular setup and SCCA vs NASA?

[rhino5oh]

I've searched for and seen a few threads on Time Trials already, but hoping to get some input & advice on Time Trials while considering my specific car and experience.

My car: 2018 GT350. Stock powertrain, stock suspension, GT4 aero, Verus Engineering wing, Watson roll bar. Car profile here.

My experience so far: 7+ years of HPDE. Running 'advanced' group with pretty much every organization I run with nowadays.

So what are the thoughts of NASA vs SCCA? After looking through some of the rules, here's my initial thoughts:

NASA
- Messing with their Classification Form (and taking guesses on weight an rwhp), It looks like I can probably fit into TT3 depending on tires used.
- Rules seem complex given the mod factors and whatnot. A good bit to think about.
- A bit of a PITA since you need to get your car weighed and dyno'd to see exactly where you fit in.

SCCA
- Mostly because of my GT4 aero, it looks like I'd be put into M2
- Rules seem a bit easier to understand since they're more related to mods done to the car, rather than horsepower (I see that weight and displacement start playing a factor once you get into the Max category)
- My personal best at VIR is within 1 second of the track record for M2 (I ran a 2.04 at VIR, the M2 record at VIR is a 2:03). This makes me believe I can be competitive, at least in this class.

Thoughts on one organization vs the other? Any feedback from fellow GT350 owners who do/have done time trials?

 

[flyhalf]

I run NASA. You are between tt2 and tr3 depending mainly on weigh and tire. It is intimidating to begin with. But after you figure out 2 things is pretty straight forward and an objective way to measure performance.
Scca is more subjective IMO. And i dont like honestly.
Nasa you have freedom for aero and mods.

You have only few mod factors.
Mainly tires and if u have sequential or paddle shifting.

My advice : play with calculator.
Select tt2.
Input your weight with u. (3950?ish?)
It gives u the max average power u can have.
Then repeat with tt3 and see what happens with max power
Power is calculated : best 8 results in the dyno. /8 to have the average max power.

First time go there and do TTU. so you dont have to play with anything.
Most of nasa events have scale and dyno there.
So during your event you can do both to know where u belong.

What tires and what weight? I can help figure out

 

[steveespo]

Class in wherever the car fits and run either or both, they are both good organizations. One thing I will caution about TT, don't expect it to be like a regular track day. Sessions are short, most competitors do an out lap, to warm tires and breaks, one or maybe two hot laps and then an in lap. Sessions are only 15 minutes with a 20 minute warm up in the morning. If track time is what you seek, TT isn't it. And it isn't cheaper on entry fees. Consumables are a little better but most front line guys and gals run new tires every event. I would suggest a NASA TREC or SCCA Endurance program if more track time is desired. Our region runs TREC events on Fridays and are either 4, 6, or 8 hour events. Your car would be classed in TREC U which means you won't compete for overall win but it is relaxed competition. As a single driver you can run 1 hour then have to take a required half hour break, our cars can go 45 minutes on fuel, so come in, get a drink, refuel rest for 10 more minutes and head back out. Only requirements for TREC are a caged car and a TT license. If you don't want to cage the car then TT is for you, but running 2:04 at VIR you should be in a caged car anyway. And yes I know plenty of people who don't. Enjoy whatever you choose.

 

[rhino5oh]

Thank you for the info and insight @flyhalf and @steveespo!

As for what tires and what weight...I haven't had the car weighed yet, but I'm about 185lbs myself, so I think 3950 with me in it is a good guess. Messing with the calculator, it looks like I'd probably be stuck with 200tw tire or so in order to make it in TT3? Maybe Goodyear Supercar 3 (non-R)?

Appreciate the honesty on track time steveespo. I haven't looked into the TREC events yet, but not sure if endurance racing would be my thing - I'll read into it a bit more. I'm mostly looking to dip my toes into something beyond HPDE, with a bit of competitive-ness. It seems like Time Trial would be a good start & a good stepping stone before getting into wheel 2 wheel

 

[mavisky]

Thank you for the info and insight @flyhalf and @steveespo!

As for what tires and what weight...I haven't had the car weighed yet, but I'm about 185lbs myself, so I think 3950 with me in it is a good guess. Messing with the calculator, it looks like I'd probably be stuck with 200tw tire or so in order to make it in TT3? Maybe Goodyear Supercar 3 (non-R)?

I don't think those will be at the pointy end of the competition sphere. I'd be looking into Yokohama A052's, Kumho V730's, or Potenza RE-71RS's.

 

[rhino5oh]

I don't think those will be at the pointy end of the competition sphere. I'd be looking into Yokohama A052's, Kumho V730's, or Potenza RE-71RS's.

All of those tires give you the same 'mod factor' according to NASA. I figured they're all very very close to each other in terms of grip . I'm a big fan of the 3Rs, actually haven't tried the regular 3's yet.

 

[flyhalf]

Thank you for the info and insight @flyhalf and @steveespo!

As for what tires and what weight...I haven't had the car weighed yet, but I'm about 185lbs myself, so I think 3950 with me in it is a good guess. Messing with the calculator, it looks like I'd probably be stuck with 200tw tire or so in order to make it in TT3? Maybe Goodyear Supercar 3 (non-R)?

Appreciate the honesty on track time steveespo. I haven't looked into the TREC events yet, but not sure if endurance racing would be my thing - I'll read into it a bit more. I'm mostly looking to dip my toes into something beyond HPDE, with a bit of competitive-ness. It seems like Time Trial would be a good start & a good stepping stone before getting into wheel 2 wheel

Supercar3 is slightly slower than cup2 but at a fraction of the cost.
3R same mod factor than hoosier so not worth it and also kind of not ideal in heavy traffic time trials. (Take long time to warm up)

Plenty plof choices for 200tw
Yoko only with 18"wheels
CRS great option.
Rival 1.5
Falken 660 (little behind)
New re71rs superfast but i think max 295.

 

[mavisky]

Supercar3 is slightly slower than cup2 but at a fraction of the cost.
3R same mod factor than hoosier so not worth it and also kind of not ideal in heavy traffic time trials. (Take long time to warm up)

Plenty plof choices for 200tw
Yoko only with 18"wheels
CRS great option.
Rival 1.5
Falken 660 (little behind)
New re71rs superfast but i think max 295.

View attachment 94817
All of those tires give you the same 'mod factor' according to NASA. I figured they're all very very close to each other in terms of grip . I'm a big fan of the 3Rs, actually haven't tried the regular 3's yet.

Yok's come in a 19, but only a 295/35-19 sizing.

Supercar 3R is a great tire, but agreed not even worth discussing when they cost you as many "points" as a Hoosier. The Supercar 3 is a great tire, just not quite at the pointy end of the performance spectrum.

I'd probably rank those tires as follows for time trials. After all you're not trying to run a competitive 20 minute session. You're basically looking for the same kind of quick to temp and then sticky for a minute or two type of performance that we're looking for in autocross.
Yok A052
RE-71RS
CR-S
V730
RT660
Cup2
Supercar 3
and then everyone else is kind of older tech or just a few tenths off of anything up above.

 

[Tonymustang302]

Im at ncm shaking the 500 down and the nankangs are fantastic

 

[67GTA]

Supercar3 is slightly slower than cup2 but at a fraction of the cost.
3R same mod factor than hoosier so not worth it and also kind of not ideal in heavy traffic time trials. (Take long time to warm up)

Plenty plof choices for 200tw
Yoko only with 18"wheels
CRS great option.
Rival 1.5
Falken 660 (little behind)
New re71rs superfast but i think max 295.

Re71RS is finally available in 305/30-19

 

[mavisky]

Im at ncm shaking the 500 down and the nankangs are fantastic

On the 350 or the 500? I know of one user who's had issues with the AR1's on a 500.

 

[mavisky]

Re71RS is finally available in 305/30-19

Yes, they are, but at like $470 from Tire Rack they're some of the most expensive options in that sizing.

 

[steveespo]

I will say this, Hoosier R7s are a whole lot different now than even 4 years ago. A set of Hoo Hoos will last 25 heat cycles (If rotated and have proper -3.0+ camber up front) and hold lap time. This is 15 cycles better than the old compound. They can be had in 315/30-18, 315/30-19 or 295/30-19 sizes for around $500 each from trackdaytire.com. That is 6-7 days of much grippier than any other DOT tire. If you want to step up to slick type tires these are for you. For trailered cars only as driving them over the road is sketchy if even a drizzle happens.

 

[rhino5oh]

Looks like I got a lot of tires to try! I'll likely be making the switch from 3Rs to R7s for a track event in June at VIR. But as for time trials, I'll be looking at everything suggested in here so far. Appreciate the feeback so far everyone.

Because of the much easier entry requirements, I'm thinking I may give an SCCA event a go first later this summer/fall to see how I like it. If I end up liking it, perhaps I'll get the car weighed, dynoed, and take it to the very edge of TT3 with NASA for next season. That's what I'm thinking for now anyways, unless someone chimes in with reason(s) to stay away from SCCA time trial events

 

[Stan Whitney]

On the 350 or the 500? I know of one user who's had issues with the AR1's on a 500.

The nankangs are underrated for a 200tw. They are very good and come in big car sizes. Only thing that outruns them are yokohama AO52. Good wear, fast to the cord, and can hook up a gt500 in 2nd gear.

For SCCA which is 200tw focused it is a solid choice. For NASA hoosier buys you more speed per mod points.

 

[JDee]

I ran AR1s for the last 3-4 years, they are a very good dry tire though pretty much a slick in the wet (which means deadly bad). They wore really well IF you have your car set up properly, they like camber. Also possibly only quasi legal on the road, depending on the mood of the LEO who pulled you over, at least up here in the land of the nanny state anyway.