7.5 lb class for GT
 

We would like to see NHRA make a 7.5 lb/hp class for Big Block combinations only.. Super Stock has the top 4 or 5 weight breaks for Big Block combos (A through E for the most part) but there are none in GT.

This would allow the top GT class to run close to the Classic Super Stock cars but not upstage them.

Re: 7.5 lb class for GT
 

Hey Bryan, you know I am all for a big block GT class, however the last thing SS needs is more classes. What they ought to do is combine GT and SS thus allowing GT cars to go all the way to 6.0 weight break. The big bonus in consolidation is more heads up runs as well. I know I am in the minority in encouraging heads up runs, but I actually like class racing more than bracket racing. Crazy, I know.

The 64 extra lbs all those 350's have to carry this year certainly does help the big block's cause though....

Re: 7.5 lb class for GT
 

I agree with both only more towards 6.0 so we can incorporate all the old Hypo motors that are locked out of competition like the Boss 429's, Tunnel Port 427's, Tunnel Port 428's, Buick Stage II's (Tom Rix's car is already ready), 421 SD's, AMC dual quad's. The 7.0 could be like the more street type big blocks only.

All with suitable after market parts to keep the cost down.

Lynn

Re: 7.5 lb class for GT
 

I go for the Combining GT and SS. Agree with reasoning. Remember Gt is already old motor/new body OR new motor /old chassis.
Dick

Re: 7.5 lb class for GT
 

You keep saying this, but how can you think that combining GT & SS would not be the end to Muscle car era race cars?

They would not be comptitive at all. Plus in SS you have to use the correct engine/tranny for the car/year. Lots of these combos are not optimal. Which leads to more $$$$ for the old cars to spend to be competitive, well at least sort of competitive.

Dick it has been what 2 years since they have opened up pre 81 cars to run GT. Has anybody been successful (ie ran fast) doing this?

Another thing to rember is that under GT rules a car uses its heaviest shipping weight +/- 250 lbs to figure class eligibilty. So lots of the old cars have to use Big Block shipping weights for GT. Which makes them run much lower heavier classes than the are currently using. Which rules would you use GT or SS? If you use SS would the cavaliers and Cobalts be legal because of moving the firewall back? If so would everyone now be allowed to move their firewall back?

Re: 7.5 lb class for GT
 

Yea, I agree that combining SS and GT is a lose lose situation for the SS cars. My Monte Carlo would have to run against the current GT/AA cars. Can you see a heads up between my 3650 lb Monte Carlo and Grossi's Sunfire or any number of Cobalts?
I know we have similar power in my car and my brothers (Firebird) and he runs 5 MPH faster, can you say aerodynamic drag! How are you going to factor that into the equation?

Re: 7.5 lb class for GT
 

I feel you guys might be correct about how to factor a BIG car small car deal being unreasonable. Even worse some underfactored motors might move up and Hit the over factored Vettes and even the Thunderbolts.
Question about SS cars? Have any regular SS cars been built in the past few years? any with the GT technology of low stance, Coil overs and LIGHT wt? I feel the Cuda AH stuff is advanced beyond any current SS cars running. GT is closer. If the GT rules were used you are right the big body would still be handicapped. Good points. With the AHFS factoring the GT cars differently than the SS or other body styles would it help? Look at the 71 vette 454, it is factored 475hp but the same motor in a GT is 440 with AL or 430 with steel heads I believe. Tough to correct this one in reverse..

Re: 7.5 lb class for GT
 

Dick brings up a good point about new cars being built. I can't remember seeing a newly built '69 Camaro come out for years, however I see a new Cobalt at almost every race.
The drag difference can be accomodated thru factoring. GT cars and SS cars have different factors for the same motor, so you simply continue this trend and have a separate factor for both styles.
I don't really think that NHRA will even consider combining classes just b/c they don't want to put up with all the whining, but it sure would be fun to actually have a heads up race or two in an eliminator for a change.
Getting back to the 7.5 lb class, Grossi's car is incredibly light and is carrying substantial removable ballast in addition to a driver who is just a touch over NHRA's allotted 170 lbs (sorry Frank). Why wouldn't Grossi just take the extra weight out and run in this new 7.5 lb class and go 8.90s? Although I love the idea of a big block class, the small blocks will just be built lighter and will always have an advantage since they will weigh 500+ lbs less.
Bryan, I think you should sell the Firebird, buy another Monte Carlo and have the two baddest SS/EA cars on the left coast.

Re: 7.5 lb class for GT
 

The minimum Wt for front wheel car is 2500 + driver. The only problem is BB are legal in them too. Will they fit? Dont know. One of the positive possibilities of Higher GT might be New Mustang , Camaro or Charger with early Motors.
There are two Thunderbolts coming out soon built to match or exceed the Hemi Cuda and Gt stuff. We will wait and see but I expect them to be awsome. People working at the intensity and dedication seen in SS/AH so far.
Unfortunately SS has seemed to be the place people moved out of so they could have the newest, slickest NEW cars. That has a lot to do with the index differences and records too. If SS classes were as heavily populated by more guys agressively developing them like GT could they be faster ?. Probably. If SS is allowed to come up to GT technology we know that will help also. The Vettes of Arts racers Kenny and Brandon are ALL moving up in technology.Eddie Smith too. Dave Thomas has been highly tech for several years. Thats why they go faster this year.
I feel if SS classes were given more ink and had a reason to upgrade more we would see the et improvement too. Not all of SS/AH is motor. The chassis upgrades allow the power to the pavement we see as et.

Re: 7.5 lb class for GT
 

Gary Merrick has a new "trick" lightweight 69 camaro built by MPR, he hasn't ran it yet though. Mcclanhan car is pretty trick and is a new PMR 1st gen camaro too. I am sure there are others.

Re: 7.5 lb class for GT
 

That is the "problem" witha lighter Gt class. You will not get any of the cool old hi-po stuff. People will take the small cavalier,cobalt cars and stuff a smog motor 454 in them and be lighter and faster. The yawn factor kicks in.

Also Dick if the GT cars ever get a 7lbs or lighter class they will run out every old muscle car from TOP SS, including the ultra trick, modern AH cars. The only way to keep any appeal is to keep Top SS old Muscle Cars entirely. No GT stuff in Top SS!!!!!

Re: 7.5 lb class for GT
 

Didn't Paquet just get his thunderbolt updated? He is still slower than Depillo ancient,outdated stuff though.

Re: 7.5 lb class for GT
 

Yeah tell this to Brian Mclanahan,Jim Weakland, Darren Smith, Brett Voges, Jeff Dona, Angelo Ditocco, Bob Harrison, Robin Brown, Larry Stewart, & the Worner Bros. Just to name a few. All these guys are ducking the real competition of the GT classes.

Dick you are drinking from the same Kool-Aid cup as Harry Holton was a couple years ago when he said in a article anyone with a SS/IA could run as fast as them(under the index) if they just worked as hard!

You continue to underestimate the talent,skills, and dedication of the Traditional SS'ers. Maybe this why you seek to force them out of NHRA drag racing by combining classes! I for one perfer watching the old traditional SS over the Gt cars.

Re: 7.5 lb class for GT
 

Agree should be 413 cubic inch rated or larger, with a minimum HP rating like 390HP at 6.0. GT/AH should be a separate class. One where all the old hypo engines with higher HP ratings be used. All reasonable aftermarket castings accepted. A Hemi Sebring, Buick Stage II Apollo, Tunnel Port Pontiac 428 Grand AM, Boss 429 Mustang LS7 Camaro, 440 6 PAC Daytona, AMC dual quad Jeep. It would make Super Stock more exciting other than watching cloned combos. I would also venture to say the 7 second barrier would be shattered! (without a turbo).

Lynn

Re: 7.5 lb class for GT
 

Great points guys.The problem that keeps popping up is the factoring issue. Just look at the current 350 chevy motors being run. Smart people keep finding underfactored motors and NHRA keeps being slow to catch on or adjust because of the weak link of the AHFS. Just another 400 motor issue.
I know a lot of people are working hard in SS and I think you missed that I believe if "allowed" the same chassis changes, 4 links, lowering of chassis as GT they would go even faster. In no way do I minimize the hard work of the racers you listed.
An awful lot of ways to go wrong on S and SS racing if Factoring isnt efficient, quick and using a human factor.(FI motors) In other words we cannot ASSUME things will correct themselves by AHFS or tech if combining classes were to occur.
I also would hate to see classes become only one car or brand allowed though like AH. A great show, killer cars and major hard work being done but missing Brand rivalry. Maybe TOP/SS needs a single Motor for each brand to run or combination. T-Bolt, Belvedere or Corvette/Camaro Only one motor choice for each.Then factoring would be EASY.
Thanks for the great wake up on the factoring problems. It could work IF .....

Re: 7.5 lb class for GT
 

Dan,

The front wheel drive conversions like Grossi's won't fit into a 7.5 lb class because it would be more than the allowed 250 lbs above or below their factory shipping weight.

You can not factor a car for aero drag since it increases as the square of the speed. This means a 10 mph head wind will have twice the effect on a on a dirty car as it would on one of the new jelly bean shaped cars. On a calm day your factoring would be fine, but at tracks like Las Vegas, Sonoma, Tucson, Fontana, Fallon... Well you see what I mean, everywhere we race, it wouldn't work equally. At Vegas I have had to dial the Monte Carlo up 2.5 tenths for the head wind. How much have you had to add in your Camaro? See what I mean.

Maybe I should build a new Monte Carlo and take advantage of the new designs, Ah hell no. If I build anything it is going to be slippery!

Re: 7.5 lb class for GT
 

I agree with your thought process here Fish, but it isnt true. Most people have a very false impression of the affects of aerodynamics of a drag car. I used software and wind tunnel coefficients to compare my 90 TA which has a .35 drag coefficient from wind tunnel testing to my 69 Firebird that has a .45. We calculated them both on a 9.90 run at 135mph. There was only a .04 difference. While that number is significant, it is not nearly what most people think. Like many issues it gets exaggerated way out of proportion.

The differences are many things not just aerodynamics. My brother's car built by MPR is closer to a Pro Stock car than it is to my old Gen 3 Firebird. He has less rotating weight, more room for straight headers, more carb spacer, more hood. I guarantee he can support traction on a 12.2 radial way better than me. His rotating weight on suspension is way lighter to reduce parasitic losses.

My Gen 3 firebird is much better than old firebirds, but there are many items that are not. The old Firebirds can fit way more spacer. We show definite HP loses on the dyno without spacer. A 69 Bird has ram air of which our motors all were rated with, but in a GT car we dont get it. The 101 wheel base of a Gen 3 Firebird is much harder to control than with the new Grand Am or the old 69 bird. I did back to back testing for my 1980 Sunbird, and we lost an average of 40HP from a 4 inch spacer verses setting the carb flat on the intake. It was so bad we must scrap the Victor intake for the Sunbird. A short runner intake with a spacer is now done and ready for testing, but we definitely are losing power due to losses in cross sectional area.

My best 60 foot is 1.29 at 2500 feet corrected. It is very hard to maintain that without the monstrous wheel stand effecting ET. The Grand Am with MPR's design and the 69 Alf Weibe Firebird will be much better in that department (especially with 70 lb cranks, 800 gm rods, and counter balances that arent pendulum cut ;)).

I have a program with several drag coefficients published by the Big 3 automakers. If anyone wants an estimate I will try to calculate it for you. However, if you analyze the numbers, a .35 verses a .45 drag coefficient represents a 28.6 increase. This calculates to .04 seconds and about 1 mph. We could easily calculate wind resistance correction within a reasonable margin for a GTAH class. Then, if someone wants to run 48 Packard refinement could be made. I would argue the Ram Air, carb spacer, wheel base advantage of a 69 Firebird equalizes or out does losses in aerodynamics if the suspension is the same level of technology.

Lynn
lmc3470@aol.com
317-839-8378

Re: 7.5 lb class for GT
 

Aerodynamics is in the picture but I agree with Lynn, probably less than people think.. All cars have some problem with head wind. Having raced at TOPEKA with an 89 camaro SS/AA and Beretta GT/GA and Sunbird GT/FA we ALL lost et and mph into the wind. I will not guess what it was but in the range of .1 to .15. I am checking with the kids for their memory.
With a rapid factoring system like the comp C.I.C. major differences might be corrected very early in the year if more class heads up racing were done.

Re: 7.5 lb class for GT
 

Lynn,

You left out part of the equation. Frontal Area.
The combination of frontal area and coefficient of drag are combined to yield total drag.

Re: 7.5 lb class for GT
 

Lynn,

Here is the equation for total drag.

Total Drag:

D=CDA p/2 V2

Where
CD= Coefficient of Drag

A= Frontal Area

p= density of ambient air

V2= vehicle speed squared

This is a big difference when you compare a Cobalt or somthing little to the Older Super Stockers with a big wide front and tall roof line.

I believe your calculations used cars with similar frontal areas.

Re: 7.5 lb class for GT
 

x2. I couldn't agree more.

Re: 7.5 lb class for GT
 

Fishlips
7.5 lbs x 322 hp = 2415 +170 for driver = 2585. Shipping weight on a Cavalier is 2617 and Sunfire is 2771. By my math they will fit in 7.5 lb class unless the 2500 lb minimum applies to car only without driver. I don't have a rulebook handy and I don't have the FWD Comp, oops I mean GT rules memorized.
Regardless, a quick phone call to Glendora by the right folks would probably allow those cars in anyway. It's not like they haven't ignored the rulebook in the past.

I'm wondering how much appeal this new class might have? I can count the number of big blocks in division 7 on one hand and the number of big block GT/AA cars on one finger. We are a dying breed my friend.

Also, in terms of new cars being built, there are at least several dozen new Cobalts running around and Chevrolet has only been making them for 2.5 years now. McClanahan's Camaro is at least 3 years old and the other car mentioned has never been run. I think this is Dick's point in that the new cars are GT cars, not old school muscle.

Re: 7.5 lb class for GT
 

Rulebook says minimum weight in GT with driver is 2670 pounds. The little teenie tiny small block cars won't measure up.

Doug

Re: 7.5 lb class for GT
 

Dan,

I guess I just hate to see the death of the big block GT car. You know there are fewer and fewer each year. Maybe the answer would be to make a big block only class in GT.

All of the really killer big block engine combinations won't factor into a GT car. GT has become the haven of the small block. Small blocks are great little engines, no doubt about it, but why can't we get some of the real factory high performance engines in GT. There is no good reason not to allow them. All of the cars these days are built to accomodate the increased speed, just look at the modified cars, so why not allow a lighter GT car with a big block?

Super Stock is all about the factory high performance cars and engines, Hemi's, LS-6's, L-88's Ford 427 side oiler, 440 Six Paks, SD455's, Tunnel ram dual quad AMC's and many others. Since GT is a modern extension of Super Stock why can't we run these engines????? Talk about Crowd pleasers!! Could you just see a new style Mustang with a 427 running a new Cuda with a 426 Hemi?

Somehow I just can't imagine a new style Cuda with a 318 in GT/HA.

Re: 7.5 lb class for GT
 

My software includes drag coefficient, frontal square area, ride height, it was all included. (cant get a number unless you enter all the numbers) You pick the vehicle from the data base for the frontal square area or you can do it yourself. Then you measure the height of the car off the ground. Yes we all know these are approximations,, and aerodynamics is a factor of many, but these big ET losses simply arent reality. (One guy told me 5 tenths)

On the other hand, how much is Ram Air, hood clearance, and wheel base worth? You gotta consider everything not cherry pick. If you want to try one I will run the software for you. I dont have all the body styles, but I have a pretty good list of the common ones.

Just think about it, you can scrub 5mph off at the end and it simply doesnt affect ET that much.

Lynn

Re: 7.5 lb class for GT
 

Lynn is this something you do commercially or just for your own edification? If you don't mind I am curious how an 85 Mustang would stack up against the Colbalts.

Re: 7.5 lb class for GT
 

I am wondering why GT starts at an 8 lb weight break in the first place. I wasn't around for the beginning of this class, so I wonder if anybody remembers the logic for this. SS starts at 6.0, so why wouldn't they just make it the same? There has to be a reason.
I agree WHOLE HEARTEDLY that a 2009 Camaro or Challenger should have a big block in it. I bet the marketing guys at GM and Chrysler would agree too.

Re: 7.5 lb class for GT
 

When asked about why the difference in wt breaks I was told it was the safety fears when the class started. As the chassis development has improved, use and speeds of Comp variety have progressed the safety has improved. Now a BBC is legal in a FWD if you chose. A new Mustang with the T-BOLT 2x4s and hemi challenger and Camaro with the L-88 heads up would be a recreation of the 60'S if supported. The factories are inquiring to get it to happen(not their motor ideas)
When asked about these lighter classes earlier the standard company answer has been "cant add classes". This area is one area progress can happen but will take time to populate with cars of any kind. If class numbers were decreased elsewhere then maybe the arguement would go away.

Re: 7.5 lb class for GT
 

Going through Indy qualifying and looked for any BB cars. Found 37,42,52,63,69 on ladder. Only 1 is a GT car. I'm sure there were others below what i guess the point is BB can't keep up. Sounds like a change would be helpful.
Jeff

Re: 7.5 lb class for GT
 

Good observation on the Indy qualifying. I know Boucher #104 has a big block in his gt/ba car and Perry #107 is also a big block. I would guess that Beechy has a big block in his gt/aa firebird (btw is he going to surprise some people that never saw him coming in gt/aa?), but cannot confirm. Regardless, 3 big block gt cars doesn't seem right.
However, would adding a 7.5lb class bring more big blocks in gt, or just isolate them from having to compete w/ the small blocks? I'm guessing the latter.

Re: 7.5 lb class for GT
 

I believe Mike Beachy is the 400 SBC. still. It was when he was in ca and da. But HP keeps getting added to it. I feel the point is valid about a change with BBC cars but not sure what it would be.
Jeff

Re: 7.5 lb class for GT
 

With a 400 in it, Beechy's car would have to weigh 2530 lbs w/o driver. I don't think you can get an '82 Firebird that light. My '85 Camaro can barely break 3000 with the big block in it. Perhaps they have the car wrong on the qualifying sheet.
GT/AA and BA class should be pretty fun to watch tomorrow. There are a lot of cars in both classes and a lot of guys sandbagging quite a bit.

Re: 7.5 lb class for GT
 

What is up with Stinnett's MPH on that 9.30 run? Seems too fast for the ET. Did he blow the tires off or something. On his earlier runs he was in the 143's. This seems more realistic for the ET.

I am stuck on the left coast and need an Indy update, anybody know?

Re: 7.5 lb class for GT
 

Beachy runs the 400. It is a new Cavalier. He put a For Sale sign on the window at Indy. Some of those 82 Firebirds with the alum hoods, I have seen very light in the 2900 lb range with driver.

Lynn

Re: 7.5 lb class for GT
 

Dont know about that, but in the final round he did a monstorous wheel stand, and headed towards the centerline, and it looked like he got out of it. Dont know what happened to the clocks. Will try to find out. That BB car is awesome.

Lynn