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L98Terror

What are the changes going to be to STR1 & 2???

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L98Terror

Are the classes staying or going ? What's going to be different?

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Greg G.
Are the classes staying or going ? What's going to be different?

They are staying. Changes are still being worked out.

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Weed Wacker

Any hints or teasers yet? Waiting on the rules to order my pistons. Dont see what changes need to be made honestly. Its the same as ST only for tube-framed cars....

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Greg G.

Ok.....teaser. We are considering some changes to the modification factors for overall weight for the cars under 3200 lbs (less of a hit for being light). It is still being debated. Also, it is being debated whether to only change STR and use it as a test before matching the changes in ST/TT/Adjusted Wt/power ratio for PT/TT classes (which would have much broader implications). In either case, the net result will be that the smaller cars may be able to run a bit more hp or less weight than in the past and still stay in their respective STR class.

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Lemming

Greg,

 

When will the 2010 rules be announced? I may be building an ST2 car and I don't want to get caught out.

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kbrew8991

STR is different than ST (fyi)

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Lemming
STR is different than ST (fyi)

 

Yes, one has an R, the other doesn't

 

I could have started another thread but didn't, just want to make sure that there are no changes to ST before I finalize my build plans.

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claykos
Ok.....teaser. We are considering some changes to the modification factors for overall weight for the cars under 3200 lbs (less of a hit for being light). It is still being debated. Also, it is being debated whether to only change STR and use it as a test before matching the changes in ST/TT/Adjusted Wt/power ratio for PT/TT classes (which would have much broader implications). In either case, the net result will be that the smaller cars may be able to run a bit more hp or less weight than in the past and still stay in their respective STR class.

 

I am very much for this. Especially at big tracks (like Miller) it's really hard for a 2500 or 2600 lb car to compete with a 3200 lb viper or corvette. I am right on the limit for ST1. I am 2500 lb and 350 rwhp. When I have to race against cars that are 3200 lbs and 550+ rwhp there's only so much I can do in the turns....

 

The heavier and higher hp car will already have an acceleration advantage even if power to weight is the same between a lighter/lower hp car due to drag. More power to overcome the drag means quicker acceleration even for the same lbs/hp.

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Weed Wacker

Awesome thanks! Now i know i should wait on the rules to order my pistons. I think i wold agree with the idea especially in STR because its even less common to have tube-frame cars to be over 3200 lbs than production cars.

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midlife

Hello

Anxiously awaiting updated changes as well. I'm building a Factory 5 Coupe for road racing anticipating its completion by spring.

Does anybody run Hoosier VRL tires? Where do you rec purchasing? Any other suggestions?

Thanks!

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L98Terror
Hello

Anxiously awaiting updated changes as well. I'm building a Factory 5 Coupe for road racing anticipating its completion by spring.

Does anybody run Hoosier VRL tires? Where do you rec purchasing? Any other suggestions?

Thanks!

 

Another ST2 car in from MI would rock, let me know if I can help in any way

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erioshi

This is actually a pretty big deal when it comes to ultra-light sports racer type cars. I think the new rules will help, but I am concerned that a very light car might be untenable unless it's sporting a turbo diesel for power.

 

Power to weight is good but it doesn't stack up when a very light (bike engined) car might be limited to something like:

 

-0.2 = Transmission: Dog-ring/Straight-cut gears (non-synchromesh)

-0.2 = Sequential/Tiptronic-like/paddle shift/semi-automatic

+0.8 = Size 9.5” (241mm) or smaller non-DOT approved

-0.75 = Non-DOT approved tires

-0.9 = 1450 lbs

 

For a total adjustment factor of -1.25 on skinny tires. With that number a 1450 lb STR1 car is limited to 1450/(5.5 + 1.25) = 214 whp and an STR2 car is limited to 1450/(8.7 + 1.25) = 145 whp. Those numbers look OK until you start to compare how a heavier car with correspondingly more HP has a much greater potential for acceleration vs drag.

 

As someone building a new car to the STR rules, it would be nice to know I could build a reasonably light,but still competitive car. Building light is a great way to reduce the cost of consumables. And if the car isn't too light (i.e. lots of specialized or custom parts) even construction costs can be kept comparatively low.

 

At this point I can go either turbo diesel or bike engine, but would prefer to use a 1 liter bike engine. Building around a bike engine really reduces both cost and complexity by a significant amount.

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Weed Wacker

These rules help out light cars a TON! In the midwest/great lakes we have ST2/STR2 champ (L98terror) and the TTS national champ Geff Sawtelle (GAS). Their track records looked almost doable with laboratory conditions at some tracks with our lighter (1380 lbs & 1550 lbs) STR-2 cars. Now with the new rules we have and amazing shot at similar times. Which obviously means the potential for close racing.

 

These comparisons are with the polar opposite - aero wise - to a sports racer, a Legends car and a Thunder Roadster. Not to mention that don't you think even with the more potential of the power:drag ratio of the heavier car, a sports racer moves through the air MUCH nicer than a street car would?

 

Both your -2 and -1 power figures can be made with bike power. Why screw with trying to fit and engine and trans separate when you can bolt in one piece and call it a day?

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erioshi

While the HP numbers are attainable, bike engines have very little torque, period. It's that part of the equation that has me worried with these really low HP numbers. It's not like a v6, v8 or v10 where the torque numbers can rescue a low HP build. Most bike engines have torque equal to 50% of their HP. So with a bike engine I'm slow out of the corners and I can't make it up down the straights, that just leaves braking & corners. Both good places to pass, but not if you get re-passed as soon as you leave the corner.

 

I guess I'm most concerned about the open tracks like Road America or VIR. There are not that many tracks left that favor momentum cars and if I'm going to play, I'd at least like to know I'll get to have some fun. I think part of my hesitation is that I haven't seen any good data for how STR will shake out yet.

 

At this point I'm still building, but I'm honestly kind of afraid to commit the back half of the car's design to a bike engine. If it's not competitive enough to be fun I will have wasted alot of time & money. And if I go turbo diesel and my build gets torque balanced then I'm out as well.

 

I feel like I may end up back trying to hit a moving target. That is a big part of what chased me out of considering a PTx build. Well, that and I do like driving sports racers... I'll still build, but I'm hoping to avoid the need to re-build.

 

Since I don't have any real data to back up my thoughts I guess I'll will to bow to your opinion for an STR2 build. Hopefully the same holds true for STR1. Oh, thanks for your input, too.

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L98Terror

Wasn't some of the closest racing this year between Matt and his torque monster L98 C4 Corvette and Richard and is little bike powered race car.

 

Also if you watch my Nationals Video those 7's only rotary powered things were hanging right with me down the straight actually I believe that on the starts some of them were pull right past me I only regained the lead by braking much, much later. I may be mistaken but rotary engines are not known for there torque.

 

IMO the only cars running to the edge of the rules are the Corvettes and we are getting punished for it.

 

 

If anyone would like to sit down and compare data I would bet a night of beers that I am not only beating the slower STR2 cars on the straight but in the corners as well and if that is the case the lighter cars shouldn't keep getting more HP.

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erioshi

I guess we may get a chance to see this plays out first hand. I was tweaking my eBay sniping software and one of my test auctions was a Yamaha R1 engine that was at a very attractive price. I ended up sniping it despite a very low bid cap.

 

So next step is building the car, lol. That will start after the holidays.

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Weed Wacker

 

 

If anyone would like to sit down and compare data I would bet a night of beers that I am not only beating the slower STR2 cars on the straight but in the corners as well and if that is the case the lighter cars shouldn't keep getting more HP.

 

Do you use traqmate? I'm planning on buying one this coming year and would be more than happy to do so with you after a few races.

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L98Terror

 

 

If anyone would like to sit down and compare data I would bet a night of beers that I am not only beating the slower STR2 cars on the straight but in the corners as well and if that is the case the lighter cars shouldn't keep getting more HP.

 

Do you use traqmate? I'm planning on buying one this coming year and would be more than happy to do so with you after a few races.

 

 

I run a GX2 so does Matt in his PTA car

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Bryancohnracing
There are not that many tracks left that favor momentum cars .

 

Just a quick point: All cars and all tracks are momentum based. Don't be fooled.

 

You gotta go 'round the corners fast in order to get down those straights fast. HP won't make up for going 30mph around T1 at Mid Ohio!

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