Street Mod.

[smoky]

Originally Posted by Suba_Roo

What is the 2020 pax number for SM on street tires for your club?
I'm very interested how much difference they think purple crack makes.

Locally we decided to keep a 0.98 factor for hoosier class that want to run street tires.

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[subydude]

Most are .98-.95 factor. Most street mod street tire local classes aren't populated by people running big street tires though, so compensation for cars that actually run big boy tires is hard to nail down until we get people actually doing it. Especially since the fast guys in SM are winning tires so buying a set of Yoko's or BFG's is an added expense. I know a few who've done it, but no ABA testing yet. Current "accepted" difference is roughly 1.5 seconds on a 60 second course between A7's and the top 200tw tires assuming the car is setup for both and it's dry.

[T-37]

A good gage is SS (.822)/SSR (.843) = .975

Not sure if this is real, or if I suck at google, since I couldn't find the numbers on the Rick Ruth site
https://www.site-watcher.com/tools/paxcalc.aspx

XSA .844
XSB .864

XSA .844 / SM .854 = .988

So it seems reasonable given the other allowances given in XS

[Gigs90]

Originally Posted by tsrapophis

So, how about that XS-A class... Our club already had a street tire PAX modifier that allowed SP and SM cars to run Street tires, so it doesn't affect our club much. But how about the guys who were already running hoosiers, are you tempted to move to a street tire?

I plan on being in this class in the Detroit / Toledo area next year just for seat time and fun. I will be no where competitive.

This class will be very interesting as there are dozens of Gridlife / GTA Street or Street Mod cars out there that could be extremely fast in the XS class.

I will mainly be doing it for fun but there are some very well sorted cars out there that could jump right in.

[Suba_Roo]

Originally Posted by smoky

Quick question, for those who have high caster and geometry correction with knuckles, how much camber are you running in front?

I have the wisefab and around 10 degrees of caster and looks like I'm eating the inside of the tire. I'm running 3.2 degrees of camber currently. On the hoosier it's not so bad, but on the RE71 I destroyed the inside of the tire in a few events only. I'll turn it down, but any pointer on how much would help save what's left on my RE71

Smoky,

Are you running both the front and rear wisefab knuckles? I just bought both and need to pick someone's brain about how the install went.

[Thorium06]

Originally Posted by Gigs90

I plan on being in this class in the Detroit / Toledo area next year just for seat time and fun. I will be no where competitive.

This class will be very interesting as there are dozens of Gridlife / GTA Street or Street Mod cars out there that could be extremely fast in the XS class.

I will mainly be doing it for fun but there are some very well sorted cars out there that could jump right in.

I think the majority of the Gridlife crowd would be eating humble pie at an SCCA autocross. Prep wise, most of those builds are far too laggy, not enough tire, too light, illegal rear wings ect. From an experience standpoint its easier to apply autocross to track instead of the other way

[Gigs90]

Originally Posted by Thorium06

I think the majority of the Gridlife crowd would be eating humble pie at an SCCA autocross. Prep wise, most of those builds are far too laggy, not enough tire, too light, illegal rear wings ect. From an experience standpoint its easier to apply autocross to track instead of the other way

Mostly correct , Many Autox cars would suffer cooling issues as well.

There are a handful of cars that could be competitive but the majority are making 500-700hp just to be competitive.

It still would be fun to go to an occasional autox but nothing will compete with some of the expensive SM builds.

[subydude]

I'd agree with both. Track and autocross generally don't cross over much when you get to the pointy ends. My car taps out around 425 whp and would have cooling issues pretty quickly on track in it's old form. New form I think it'd be fine on track at a bit lower boost. Next turbo I swap in it'd be 500 whp, no cooling issues on track, and no need to lower boost so it could cross over....with a cage.

Track cars do usually have elevated power bands, smaller tires, etc. Although sometimes I wonder about that because having thousands of laps under my belt across 7-8 tracks I'm often exiting corners around 4k rpm, even in ****boxes. In a turbo car I'd rather have a turbo that came alive at 3,500 and lived to 7k vs one that didn't come on boil until 4.5-5k.

And Chris is right, autocrossers often make good road racers, but road racers rarely make good autocrossers, at least until they get used to way faster inputs and reaction times.

[Gigs90]

Yeah you build the entire chassis around the intended use

You rarely see Hoosiers on TA cars as they are only for the Unlimited class which has maybe a half dozen Subaru's in the country.

Every SM car seems to be running them and some lunatics even stuff 315s under them.

[Homemade WRX]

Time attack street mod has me capped at 255 200 utqc tires....but the cars are chasing 600-800 whp to be competitive.

Those two statements rule it out as a competitive autox car in my mind.

Of course tire swap, suspension adjustment, turbo swap, and then you'd have a decent set up but carrying a lot of cooling weight now. If you're dialing in diffs, you'll be way off too.

[speedyHAM]

Originally Posted by Homemade WRX

Time attack street mod has me capped at 255 200 utqc tires....but the cars are chasing 600-800 whp to be competitive.

Those two statements rule it out as a competitive autox car in my mind.

Of course tire swap, suspension adjustment, turbo swap, and then you'd have a decent set up but carrying a lot of cooling weight now. If you're dialing in diffs, you'll be way off too.

+1. This could not be better stated. The two venues are too far apart to have a single car that is competitive in both.

[Homemade WRX]

Oh and the wings allowed in SM time attack classes will be terrible at autox. Limited in size and to a single element.

[subydude]

Originally Posted by Gigs90

Yeah you build the entire chassis around the intended use

You rarely see Hoosiers on TA cars as they are only for the Unlimited class which has maybe a half dozen Subaru's in the country.

Every SM car seems to be running them and some lunatics even stuff 315s under them.

I run 335 A7's under my 2000 Impreza We run them because they're the fastest tire AND have great contingency. Winning 18 tires in 2017 really helped develop the car since I didn't have to worry about buying tires and could actually sell some too.

Originally Posted by Homemade WRX

Time attack street mod has me capped at 255 200 utqc tires....but the cars are chasing 600-800 whp to be competitive.

Those two statements rule it out as a competitive autox car in my mind.

Of course tire swap, suspension adjustment, turbo swap, and then you'd have a decent set up but carrying a lot of cooling weight now. If you're dialing in diffs, you'll be way off too.

I've seen 600 whp autox cars, but most AWD (outside of the GT-R's) usually tops out around 550 whp to stay competitive on spool.

The suspension/diff/etc could be fixed, but I agree that I wouldn't want my autox alignment out on track, and I would probably set the rear diff up to have more stability.

Originally Posted by speedyHAM

+1. This could not be better stated. The two venues are too far apart to have a single car that is competitive in both.

I think you could swap between, but it'd be a lot of work, and honestly for most of us we only have the budget to pursue one thing, and autox is a LOT cheaper than TA in street mod classes (from what I've seen).

Originally Posted by Homemade WRX

Oh and the wings allowed in SM time attack classes will be terrible at autox. Limited in size and to a single element.

That's easy to fix. Just take the upper element off the autox wing! Or swap the whole shebang. It's 4 bolts that hold the wing onto the up rights so it'd be relatively easy to swap another wing on, and if it's a single limited in size it wouldn't be hard to fab something up that would work for "cheap".

It'd be the under body and splitter aero that I bet would take a lot more work to figure out.

[speedyHAM]

Originally Posted by subydude

I think you could swap between, but it'd be a lot of work, and honestly for most of us we only have the budget to pursue one thing, and autox is a LOT cheaper than TA in street mod classes (from what I've seen).

If you had that kind of time and money on your hands I don't think you'd be looking at AutoX. I envision diff setup changes and alignment changes needed between each event, and that gets costly and time consuming fast. I think we agree on this point.

[Gigs90]

With the money people drop on street mod or Track mod it would honestly not surprise me

I am not sure if you guys have heard of UMI King of the Mountain but it has a pretty nasty lineup. Gridlife Track Mod champion Jeremy Swenson won the entire event last year and $10,000. Jeremy and Mr Fleming are insanely fast Corvettes then you have people like Ravenek who is a seasoned One Lap of America driver.

Some of you should enter it looks like one hell of an event

[Homemade WRX]

Originally Posted by speedyHAM

If you had that kind of time and money on your hands I don't think you'd be looking at AutoX. I envision diff setup changes and alignment changes needed between each event, and that gets costly and time consuming fast. I think we agree on this point.

This is my bigger point. It's not that it can't be done but it would be a massive time suck to swap and adjust everything. So much so, a second car would probably start looking like a pretty good idea

Originally Posted by Gigs90

I am not sure if you guys have heard of UMI King of the Mountain but it has a pretty nasty lineup.

Hmm, only a little over 500 miles away.

[smoky]

I just switched to a link G4X. I was pretty excited to test the antilag feature on the track, but my tuner warned me that I might have brake booster issue, since it will impact the intake vacuum condition. Anybody here using antilag? Worth it? Issue with brake booster? Turn around?

[Homemade WRX]

Running a fresh air system or traditional ALS?

[subydude]

Originally Posted by smoky

I just switched to a link G4X. I was pretty excited to test the antilag feature on the track, but my tuner warned me that I might have brake booster issue, since it will impact the intake vacuum condition. Anybody here using antilag? Worth it? Issue with brake booster? Turn around?

You'll either need a vacuum pump, or a big canister to add capacity.

What header are you running? ALS puts a LOT of heat into the header, exhaust valve seals/valves, and turbine. Short bursts is fine for a while, but a lot of it will cook a lot of stuff quickly.

[Homemade WRX]

Originally Posted by subydude

You'll either need a vacuum pump, or a big canister to add capacity.

What header are you running? ALS puts a LOT of heat into the header, exhaust valve seals/valves, and turbine. Short bursts is fine for a while, but a lot of it will cook a lot of stuff quickly.

Or run a fresh air system that completely bypasses the engine.

[T-37]

Wouldn't that fresh air als still be making at least zero manifold pressure with the fresh air valve open? If it was operating under vacuum it would be DEI wouldn't it?

Edit: I've heard of people using the group n booster delete, but it requires a different pedal rod.

[smoky]

Originally Posted by T-37

Wouldn't that fresh air als still be making at least zero manifold pressure with the fresh air valve open? If it was operating under vacuum it would be DEI wouldn't it?
Edit: I've heard of people using the group n booster delete, but it requires a different pedal rod.

I thought about brake booster removal a while back, it's a good weight saving option, but apparently the ABS stop working properly when you do so...

[smoky]

Originally Posted by Homemade WRX

Running a fresh air system or traditional ALS?

ALS only, was just curious to test it out and see how it works. Still need to dig into this ECU and the software to understand it better.

[smoky]

Originally Posted by subydude

You'll either need a vacuum pump, or a big canister to add capacity.

What header are you running? ALS puts a LOT of heat into the header, exhaust valve seals/valves, and turbine. Short bursts is fine for a while, but a lot of it will cook a lot of stuff quickly.

I use the Tomei with a cheap ceramic coating and heat wrap. Not sure they would survive long...

[subydude]

Originally Posted by T-37

Wouldn't that fresh air als still be making at least zero manifold pressure with the fresh air valve open? If it was operating under vacuum it would be DEI wouldn't it?

Edit: I've heard of people using the group n booster delete, but it requires a different pedal rod.

A fresh air system just focuses on turbine wheel speed so the throttle plate would still close and create vacuum.

Originally Posted by smoky

I use the Tomei with a cheap ceramic coating and heat wrap. Not sure they would survive long...

It would be very short lived. I’ve used ALS before to launch my car and if I held it down for more than 3ish seconds I saw the egt gauge go past 1,800 degrees. Granted, I had made it pretty aggressive, but it was making 25 psi sitting still.

If you did a more mild setup it “might” live longer, but it’s a lot of heat.

The fresh air setup is a lot more complex in terms of ECU setup, and you have to fabricate some fun bits, but is considerably nicer to your equipment.