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Seems to me that with all these obsolete corvettes around, now would be a good time to look at a rewrite of BP. Corvettes only, any rear gear, stripped interior, cage if you want it, any DOT tire wheel combo up to 13" wide and any camshaft. Any OEM small block up to 5.8 litres.SP rules for the short block to keep cost down. No dry sump. 2800 lbs min weight. No plastic for windows. Years C4-C5 only. What do ya think?

I don't own a Corvette but I do see a place for all the old cars to run.

Chris

The idea of a spec C4/C5 vette class is intriguing.  

But I'd force them to run stock wheels and stock engine internals.  

Stock body panels, flaring or cutting fenders is fine.  No aero.

No Z06's or ZR1's.  

 

How light can you get one if you strip it out?  How cheap could you build one?

Sounds like more fun than CP.  :) 

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Robert Puertas
www.EvoSchool.com

Sounds like the old BP.  That worked pretty well...

DaveW

Except for the SP short block, DOT tires, and C4/5 only.

Why only C4/C5s?

And why no slicks? 

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Steve Hudson
DP Miata

Those are the bulk of the BSP cars that are obsolete. Slicks cost a lot more in 18 inch sizes and the current DOT tires work really well. It would also open the doors to more contingencies. Look at how fast SM cars on DOT tires. I would suspect that the C6 could come play in a few years. I would also suggest that the C6 Z06 would only be allowed with a bone stock engine minus mamifolds and flywheel.

It is a concept for a totally NEW BP. I suspect there are a lot of those C4/5's out there that would love to play in this more modern, less prepared, less expensive class. I am considering proposing it to the PAC.

Like I said, " I don't own a Corvette" but I think it would be a nice way to revive BP. Does anyonw out there know what a stripped C4 would weigh?

Chris

Any reason not to go ahead and allow older 'vettes, then you'd have more potential cars for the class.

What about the Mustangs with IRS that are not in CP? 

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Steve Hudson
DP Miata

You could allow them but I don't think they stand a chance against the newer cars. Mustangs belong in CP IMO. I don't like the steel vs fiberglass thing.

Howdy,

Interesting...

C4 and older.  I think c5's will dominate and I don't think they're cheap enough to "destroy" yet.

Unlimited wheels / DOT tires only.

Not sure on motors... Potentially limit to SP + cam?  If you allow heads, you might as well allow any iron block chevy based motor, including racing blocks, that are wet sump.  Heads/compression/cam on smallblock is going to get you as much power as you can use anyway, so why not let folks play.  Certainly you at least want to allow someone to build a budget 383 vs. requiring them to spend real money on a 355.  No weight breaks based on displacement.  Motor can't be relocated.  No ZR1 motors.  Any induction/exhaust.

No dog ring gearboxes, any replacment trans must be at least a five speed plus reverse.

No cf driveshafts, otherwise free.

Any rear gear or diff in the stock housing.  Any axles.

Can't modify the chasis side suspension pickup points, must use stock spindles, and can't cut the frame rails for clearance (not sure if this is an issue...).  All other suspension/brake/etc. modification is free.  Specifically allow "mini-tubbing".

No wings, splitters, belly pans, or rear diffusers.  Spoiler is ok (i.e. existing CP rules for aero).

Allow fuel cells in the rear and keep the radiator in the front.

Must retain stock floor / trunk area, except allow for modification per SM's "you can do stuff up to a pound to get other legal things installed".

non-stock ABS & Traction control are prohibited.

Update and backdate allowed, and allowed to cross chassis lines for drivetrain components.

Maybe other stuff?  What was the recipie for a fast/cheap BP corvette?

Mark

I would say C4 C5 non Z06 only than. Try and keep it a little more modern. Let's not turn it into GP from the get go.I think the problem with the 383 is that a smart guy would build that motor to the limit making everyone have to do it. Stock crank rods keeps the budget down. You could allow one aftermarket cylinder head that is better than OEM bow tie for the aluminum blocks and one for the cast iron blocks. It would have to be an off the shelf complete cylinder head to keep the cost down. Keep camshaft lift to .625 lift max at the valve. Again to keep cost down and power in the 550 ish range. Can't use much more than that any way.

 I would say that the dog ring gear box is ok. Jerico is not that expensive and they are very tough. I would consider the Jerico an investment in reliability.

Fuel cell is ok but must be 15 gallons min.

SM brake rules.

CP rules for aero.

Stock floor/ trunk area except SM ok with me.

Update backdate within chassis line only.

Any rear gear and limited slip.

Stock uprights. Stock pickup points. Stock control arms. Heim joints allowed.

SP shock rules.

Removal of bumper struts and reinforcement allowed. Stock bumper covers must be used.

Chris

Howdy,

With the rules you're proposing, what's the difference between a c5 z06 and a '99 FRC?  What you're proposing is "spec c5" if you let them in...

Build the 383 to the limit and you'll get a ton of power, no question.  But can you use the power?  I don't think you can.  We don't need rules that promote hand grenade motors, and using displacement or block limits to try and limit power does just that.  If this wasn't just a pie in the sky deal, I'd say to do what I wrote above.  But if I can waive my magic wand, I'd spec a crate motor.  :-)

Good idea to limit the size of the fuel cell.

Aftermarket control arms should be legal... They are in SM already and you're allowing spherical bearings below.  Not allowing them isn't, to me, consistent with what I think the class should target or Prepared as a whole.

I'm not sure there's much of a difference between SP shock rules and "chassis side pickup points must remain in the stock location" in reality...

CHRISFP78:

I would say C4 C5 non Z06 only than. Try and keep it a little more modern. Let's not turn it into GP from the get go.I think the problem with the 383 is that a smart guy would build that motor to the limit making everyone have to do it. Stock crank rods keeps the budget down. You could allow one aftermarket cylinder head that is better than OEM bow tie for the aluminum blocks and one for the cast iron blocks. It would have to be an off the shelf complete cylinder head to keep the cost down. Keep camshaft lift to .625 lift max at the valve. Again to keep cost down and power in the 550 ish range. Can't use much more than that any way.

 I would say that the dog ring gear box is ok. Jerico is not that expensive and they are very tough. I would consider the Jerico an investment in reliability.

Fuel cell is ok but must be 15 gallons min.

SM brake rules.

CP rules for aero.

Stock floor/ trunk area except SM ok with me.

Update backdate within chassis line only.

Any rear gear and limited slip.

Stock uprights. Stock pickup points. Stock control arms. Heim joints allowed.

SP shock rules.

Removal of bumper struts and reinforcement allowed. Stock bumper covers must be used.

Chris

Hey, this is my new class not your 

 Someone would build the 383 so everyone would have to. That's why I say no to it. If the C5 is a deal breaker than I say no C5. I personally think that the C5's are old enough to play though. One thing you could do is say stock trans axle for the C5 vs Jerico for C4 to help equalize. Might need an extra 50 lbs on the C5.

Thinking about it, I say keep the engine OEM except for camshaft. Allow mix and mach of OEM engine components to keep cost down.

 

 

CHRISFP78:

Hey, this is my new class not your 

 Someone would build the 383 so everyone would have to. That's why I say no to it. If the C5 is a deal breaker than I say no C5. I personally think that the C5's are old enough to play though. One thing you could do is say stock trans axle for the C5 vs Jerico for C4 to help equalize. Might need an extra 50 lbs on the C5.

Thinking about it, I say keep the engine OEM except for camshaft. Allow mix and mach of OEM engine components to keep cost down.

 

Good luck policing that class.  BTW, SM is so damn fast because there are no limits on expenditures.  Traction control, big turbos/superchargers and only a few of them are that fast.  Cost effective but allow a Jericho, come on?  Like you said, it is your class 8-))  You might want to put on your armor shielding because the guys with the older vettes are going to come for you!

 

 

 

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turbotoddie
todd farris
CP96

I doubt it. They won't even go to nationals to save there own class. I think SM as fast for two reasons. First, we have two great drivers at the top of the class. Second, they are well set up cars.

Jerico's are cheap IMO. A magnesium dog gear 4 speed that weighs less than 65 lbs and can take 800 plus hp is cheap. Plus they sound cool as hell.

Chris 

What was BP like before the RX7's showed up?  I like some of these ideas, but you have to allow a set of heads with any cam.  Coil-Over shocks are available and affordable bolt-on option ($1,790.00 for the complete set), cheaper than 2x adjust Penske's! 

Dry sump is a popular mod for the C5.  I have personally blown a motor do to oil starvation in high G cornering at an auto-x!

LIKES 

Corvettes only 

2800 lbs min weight

No plastic for windows

stripped interior 

cage if you want it

No cf driveshafts, otherwise free.

Any rear gear or diff in the stock housing. 

Any axles.

any DOT tire wheel combo up to 13" wide 

Slicks (weight penalty) 

No wings, splitters, belly pans, or rear diffusers.  Spoiler is ok (i.e. existing CP rules for aero).

Allow fuel cells in the rear and keep the radiator in the front

Must retain stock floor / trunk area, except allow for modification per SM's

non-stock ABS & Traction control are prohibited

Update and backdate allowed, and allowed to cross chassis lines for drivetrain components

 

Don't Likes 

Years C4-C5 only.  - need to let C3's play if they want

stock wheels and stock engine internals

No Z06's or ZR1's.  Why not a C5Z?

I think c5's will dominate and I don't think they're cheap enough to "destroy" yet. - I believe they are, just harder to find

Not sure on motors... Potentially limit to SP + cam.  Gotta have a good set of heads with a nice cam

No dog ring gearboxes, any replacment trans must be at least a five speed plus reverse.  A built replacement will cost close to a dog ring gearbox (C4 and older). 

 

 



What's the deal with No ZO6's?  do you mean C5Z's or C6Z's because the C5Z is such a great platform to start with and not far off from a regular C5.  Many C5Z owners with heads and cam only participate in open track events now because there's no realistic place to play in auto-x.  Can't stay in ASP, but aren't nearly as built as a SM2 car!  Just my perspective with the open trackers

-Joel Villarreal 

 

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joel villarreal
39 CP
126 ASP
www.americanauto-x.com

I think a lot of those things could be added over time, but not right away. Slicks, no way. Cost to much for to little return. Not to mention you would need another set of wheels. The other big problem is the heat cycling of slicks. To be competative it cost 2x wat DOT's do.

No C6 for at least 10 years. No C5 Z for 5 years. You could put that in the rule so people could plan for it's arrival. No C3's. Don't want a GP problem in the first 5 years of the class.

Late

CHRISFP78:

I think a lot of those things could be added over time, but not right away. Slicks, no way. Cost to much for to little return. Not to mention you would need another set of wheels. The other big problem is the heat cycling of slicks. To be competative it cost 2x wat DOT's do.

No C6 for at least 10 years. No C5 Z for 5 years. You could put that in the rule so people could plan for it's arrival. No C3's. Don't want a GP problem in the first 5 years of the class.

Late

I will agree with the Slicks being to expensive, but excluding C5 Z06 does not make complete sense.  There isn't much difference between a Fixed Roof Coupe (FRC '99-'00) corvette and a Z06. 

1. The most obvious is the LS1 motor vs the LS6 motor.  The heads, cam & Intake are the only True performance differences and the proposed open Cam and "Off the shelf" GM heads rule would override that.  Valve springs are different (Z06 rated up to a mere .560 lift), pushrods are the same.  An aggressive cam requires changing both.  Intake is certainly proven to produce more horsepower, but after 2002 all Corvettes came with the LS6 intake.  There are some structural differences in the block but minor in my opinion.

2. Suspension is identical except shocks and Swaybars.  Shocks rule is open.  Rear Sway bars (23.6 mm) are the same.  Front sway bars are Different but if we are borrowing SP rules that is open. 

3.  Transmissions do have different gearing, but over-rided with the proposed Update/Backdate rule (maybe/ maybe not).  There has been discussion of running a "stock" Z51 transmission in a Z06 with a lower Rear-End gear that gives you nearly identical ratios to the stock Z06 transmission in 1st & 2nd but with a higher mph in 2nd.  Clutch, flywheel and pressure plate are different, but open in SP.

4.  The Z06 is about 130 lbs lighter do to a few things.  No interior sound deadening,  thinner front windshield & TI Exhaust.  Can't do anything about the Windshield but can put TI Exhaust on that gutted Z06. (Exhaust is open)   Other things are, Power Antenna, Telescopic wheel, 6 disc CD Changer and a few other odds and ends.  Most if not all will be removed.

5.  Brakes calipers are different.  Rotors are the same.  under SP rules, brakes are open. 

6.  Z06 has brake ducts.  Fronts ducts can be added without any cutting.  Rears will require a hole in the rocker, but it's debatable if they actually do anything!   Rears will need modifications if you mini-tub to run wider tires. 

 
Besides a more expensive starting point, I can't see a overwhelming reason to prohibit the Z06.   Chime in if I have missed something.  A base C6 (2005-2007) are nearly identical to the C5 Z06.  I can see no C6's for 5 years, not 10.  And where are the C3's going to go play?  Sam Platt and his C3 could certainly win BP? 

-joel

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joel villarreal
39 CP
126 ASP
www.americanauto-x.com

I still say no C3. The old cars are over prepared for the new class any way. Can you say E-Mod.

If the Z06 is that good, it will dominate the class. Might have to put 100 lbs on the Z06 so the C4's can compete.

If the stock trans are ok than let's go with update backdate on transmission but allow any rear gear.

LS6 or equivelent for cylinder head to keep cost down. Valve springs are open to accommidate larger cam shafts.

 

 

Hey guys, I need to check in more often, it's been a few weeks.

  Anyways, looks like something similar to the BSPV class we have in the American Autox Series, I think it's a very good idea, getting people to run it will be a challenge. Joel has some good points, the C5 Z06 should not be a factor given the mods that are being proposed/allowed. To me it seems as though the C5 FRC will be the best choice whether the Z06 is allowed or not, if you guys want a class for the the C4, then don't allow the C5.

 

Jesus

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Jesus Villarreal
D mod Europa

All good ideas.  I'd keep the C5Z's in, given the heads/cam swap options - in P trim you negate the other weight saving items anyway.  Add weight to the C5's to get parity with the C4's, or mandate a rear weight %.  The C4 could be the better car at similar weight/power - shorter wheelbase, and narrow.

Take a look at some of the limted prep wording being proposed in this months fastrack for the new GP.  It could be recycled to fit (bodywork, suspension prep, engine prep).  A 'limited prep' model for future P classes may be good thing to start. 

Weight wise, a C5 can get down to 2500lbs with a cage without exotic lightening.  Subtract 100lbs for a no-cage weight.