Landracing Forum
Tech Information => Technical Discussion => Topic started by: SaltGTA on March 29, 2006, 05:49:36 AM
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Hi all,
I'm in the beginning stages of building my street car for Speed Week out in Wendover, but I'm learning that there are an awful lot of things that I don't know, & I'm hoping that I can make use of some of the experience here. I'm not trying to set any records, I'd just really like to get my name in the 130 Club.
My car is a 1989 Trans Am GTA (http://www.gtasourcepage.com/89PhotoGalleryPics/markusgta1b.jpg) with the L98 350 (hyd. roller cam, Tuned-Port Injection). My plan is to drop the current 4-speed auto for a 6-speed manual as soon as I'm able. I know that the stock long-runner intake isn't ideal for what I'm trying to do, so I've gotten a Holley StealthRam (http://stealthram.com/flowcomparison.html) intake, which I'm thinking should work reasonably well with the AFR 195 heads that I've also bought. My main problem right now seems to be that I don't have a precise idea of what's needed to get into the 130 Club. (Yes, I have read the rules for the event. :) )
A good example of this is my struggle to pick the right cam - there are a lot of factors that I do know (car's wt is ~ 3650, RPM range is 6k or less, & still has power brakes & the stock ECM, & has to pass emissions). I already have a pretty good exhaust setup on the car, and larger injectors which should be a better match for the increased airflow. (I'll also be getting a custom tune to take full advantage of the new hardware.)
There are also a lot of things that I'm not sure about:
* the biggest of these is rear gearing - do I want a fairly tall gear like a 3.08, or can I get by with something more "street-friendly" like a 3.42?
* Also, in order to put this car solidly into the 130s on salt, roughly how much HP will I need? (I'm fairly sure that the car's frontal area is about 24 sq. ft., & the car's Cd is about 0.31, maybe 0.30.)
* Is there a practical way for me to figure out the gearing I'd need to run 130 at the end of a standing mile? (I've just checked, & the rear tires I have are pretty close to 26" diameter, & 9.5" wide...)
As you can tell, it's a bit tough to pick a cam without having good answers to these questions. I also have a couple more questions that don't really "fit" with those above:
* Would it be worthwhile to lower the car by 1 or 1.5 inches?
* What kinds of other things can I do to increase my chances of a successful attempt?
I'm sorry that this got so long-winded, I figured that I'll be able to get better answers by including a reasonable amount of relevant data. Any constructive thoughts/feedback are much appreciated.
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Could be, that you are in the wrong meet :? :?
The 130 Club is during the World of Speed in September, this is the meet of the USFRA. If you go on there website - there is button on the cover page of the Landracing.com - you will find the missing link :wink:
Think fast.....always
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Could be, that you are in the wrong meet :? :?
The 130 Club is during the World of Speed in September, this is the meet of the USFRA. If you go on there website - there is button on the cover page of the Landracing.com - you will find the missing link :wink:
Think fast.....always
Thomas,
Great info and beat me to it.
Way too go.
J
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I'm not sure I understand the above responses. He was asking for advice on choosing proper gearing for the salt. As he mentioned in his post he has already found the rules for the 130 club, and knows the basic event information.
As I read his post, he is looking for some tech assistance in selecting proper gears the first time out, and nailing down the most likely engine rpm range he will need to target with his cam selection.
Larry
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Hotrod,
at first, SlowGTA (why slow, can this be slow :shock: ) wrote Speedweek - if comes in August to the salt and likes to go for the 130 Club, he would be very disappoint that they park him to September :P .
Second, I'm not sure if he really read all the 130 Club necessary rules, otherwise, some of the question could be answered by the rule...not allowed...may be :x .
Second, over this web site and information he can get the contact addresses from people who runs the 130 Club and they can give him the support he need. The 130 Club is not a club for records, the idea is more to prove if the car, with the necessary protction equipment installed, will go a speed of 130 mph, once you reach it you be out of the competition with this car. So everybody is a winner.
This was the reason why I spot the USFRA website.
See ya
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As I understand it the 130 club rules consist only of these provisions.
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Utah Salt Flats Racing Association
130 MPH Club Rules
Revised 01/06
? All drivers must be members of USFRA, hold a valid state drivers license, and sign a loss damage waiver to participate.
? A maximum of five (5) runs will be allowed per entry fee paid.
? The 130-mph format is specifically designed for street cars and motorcycles. To gain Membership in the 130 MPH Club, the vehicle must run the course twice in the same day at a speed no less than 130 mph the two runs are then averaged. A two run average over 130 MPH and under 140 MPH makes the driver a member of the 130 MPH Club. Once a driver has achieved 130 MPH Club Member status no more runs will be allowed.
? An acceptable speed indicator is required so the driver has an indication of the car's speed at any point on the course.
? An initial "licensing" pass at no more than 100 mph will be required to calibrate the on board speed gauge equipment. i.e.; tachometer, speedometer, etc.
? Maximum speed will be 140 mph - any vehicle exceeding 140 mph will be disqualified from making anymore passes and will not receive a timing slip.
? Drivers will be required to participate in a driver orientation meeting with an experienced salt flats driver prior to racing.
? The driver must wear a Snell 2000 or newer Snell approved, full-face helmet, long sleeve shirt or jacket, long pants and closed shoes.
? Motorcycle riders must wear full leathers, either one piece or zip together waist, including leather boots and leather gloves.
? Open Cars must have a 4-point or more roll bar. Vehicles with factory Glass T-Top inserts or any vehicles aftermarket roof modifications are consider to be ?Open Cars?. Vehicles with removable ?Hard Tops? (such as Miata, Boxter, ect.) are also considered to be ?Open Cars?. .
? Cars must be equipped with OEM (or better) lap and shoulder belts. If vehicle was manufactured prior to belts, they must be added. Properly installed 4 point or more seat belt harnesses are allowed and encouraged.
? Only gasoline, diesel, ethanol, bio-diesel, electric, propane, or natural gas fuels may be used - NO Nitrous Oxide, Methanol or Nitro-fueled vehicles will be allowed.
? Cars must have an adequate battery tie down installed.
? Drive line retention loops are required in the front 25% of each section of drive shaft on rear-wheel cars where adequate retention and control of a broken driveline is not assured by body/frame design.
? Dual throttle return springs are recommended. Proper operation of the throttle return mechanism will be checked during inspection.
? Vehicles must have H, W, Y, V, or Z rated tires which are rated for speeds in excess of 130 mph. Because the sidewall marking systems vary greatly among tire manufacturers, it is the responsibility of the driver/owner to provide objective evidence of the speed rating of tires.
? Tires & wheels for all vehicles will have metal valve caps (metal valve stems are highly recommended) & crack-free valve stems. No tires wider than 10" will be allowed, unless the tires are OEM to the vehicle. (Narrow tires provide better stability on the Salt).
? Wheel covers (hubcaps) will be positively attached or removed.
? All cars will have a small fire extinguisher securely mounted inside the vehicle.
? An impermeable ground cover that extends at least 3' past each side of the vehicle must be used under the vehicle in the pit area. Waste fluids will not be "dumped" they will be taken off the salt for disposal. Pit areas and general Salt will be kept neat and clean at all times
? Rental Cars will not be allowed.
? INSPECTION:
? -All vehicles must be currently licensed and street legal in their respective state.
? -Fees will NOT be charged for an inspection.
? -Inspection will verify the acceptable condition of the engine, drive train, wheels, tires, fuel system, steering, braking, and safety systems to an approved checklist.
? -Decisions of the inspector are final in the areas of safety assessment and requirements.
Course:
The Course will be a 1 mile long course with a 132 foot precision speed trap at the end of the mile.
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The bold entries are the only provisions that directly refer to the mechanical equipment in the cars, so there are apparently no limitations regarding gear selection or engine design (ie cams etc.) which was the primary question posted.
Frankly I'm puzzled that no one has even offered a tangible comment on his primary concerns --- specifically how do folks that run on the salt choose their gear ratios and what engine characteristics seem to be most desirable (ie how to cam the engine).
From every thing I've seen the main hurdle for drivers trying to get into the 130 or 150 club is the limited traction available and the short acceleration zone. Most any high performance car could easily get to 150 with a little longer starting zone, so the challenge is to get good acceleration with out over-powering the traction available.
This would imply you want a very flat torque curve and gearing that is designed to keep the engine pulling hard (ie close ratios with out too much low gear). The whole pass only lasts 35 -50 seconds so you don't have much time for the car to pull up to its aerodrag limited speed.
Larry
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Sorry for not checking in sooner.Ran maxton 135 at 5800 rpm.Eng 60 over 327.rpm performer intake 650 holley,cam (stock?)turbo 350 thans,3.42 10 bolt rear,28 in tire. I know the two surfaces are worlds apart,but 300hp308 gear good shocks tires and go low 130-140 should be no problem for you (i have a tall s-10) much luck. terry
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Hey Terry, thank you for the response, that does help a bit. :)
Frankly I'm puzzled that no one has even offered a tangible comment on his primary concerns --- specifically how do folks that run on the salt choose their gear ratios and what engine characteristics seem to be most desirable (ie how to cam the engine).
Thanks HotRod, I am too. Puzzled & more than a bit surprised. Fortunately, I've gotten a PM from someone who is willing to help (which I'm very appreciative of), & I'll be following up on that. Thanks again.
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I think the cam grinder can best answer your question about gearing. You need to tell him the engine modifications and let him select a cam grind most appropriate for the most power. He can also tell you where the peak horsepower is most likely to be. I don't know about the 6-speed you're planning to use, but if 4th gear is direct (1:1), then you won't lose any power in using an overdrive 5th or 6th. Using a Dream Wheel or Landracing's Gear Spitter program, enter the tire size, the cam grinder's peak power RPM and 130+ miles per hour and the gear ratio can be selected to obtain that result. Now I can't tell if that's going to be enough power or too much air drag, but if you got that motor with that power and that gear, it's your best chance to go 130+. Best of luck!
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My car is a 1989 Trans Am GTA (http://www.gtasourcepage.com/89PhotoGalleryPics/markusgta1b.jpg) with the L98 350 (hyd. roller cam, Tuned-Port Injection). My plan is to drop the current 4-speed auto for a 6-speed manual as soon as I'm able. I know that the stock long-runner intake isn't ideal for what I'm trying to do, so I've gotten a Holley StealthRam (http://stealthram.com/flowcomparison.html) intake, which I'm thinking should work reasonably well with the AFR 195 heads that I've also bought. My main problem right now seems to be that I don't have a precise idea of what's needed to get into the 130 Club. (Yes, I have read the rules for the event. :) )
A good example of this is my struggle to pick the right cam - there are a lot of factors that I do know (car's wt is ~ 3650, RPM range is 6k or less, & still has power brakes & the stock ECM, & has to pass emissions). I already have a pretty good exhaust setup on the car, and larger injectors which should be a better match for the increased airflow. (I'll also be getting a custom tune to take full advantage of the new hardware.)
There are also a lot of things that I'm not sure about:
* the biggest of these is rear gearing - do I want a fairly tall gear like a 3.08, or can I get by with something more "street-friendly" like a 3.42?
* Also, in order to put this car solidly into the 130s on salt, roughly how much HP will I need? (I'm fairly sure that the car's frontal area is about 24 sq. ft., & the car's Cd is about 0.31, maybe 0.30.)
* Is there a practical way for me to figure out the gearing I'd need to run 130 at the end of a standing mile? (I've just checked, & the rear tires I have are pretty close to 26" diameter, & 9.5" wide...)
If you just want to run the 130-140 mph at the Sept. World of Speed and you still want to keep the car as a street car I would look at trying to get it in the 425-450 hp range and that isn't hard with the AFR heads and a mild roller cam. With a 5500 rpm limit and the 26 inch tires you could get there with a rear gear of around 3.00 in 3rd with the OD 4 speed or in 4th with the standard. I would try and gear to stay out of overdrive with either transmission. Now if you picked up some 28 inch tires to run there with you could go with 3.43 gears and the car would be much more drive-able on the street in overdrive and still keep good acceleration on the street in the lower gears with the 3.40's.
Call comp cam or one of the other cam manufactures and give them the hp range you are looking to run at say 5500 rpm and get a recommendation for the cam. You are going to have to have a different chip burned for the ECU or do something there to handle the cam, heads and exh..
Here is a good place to figure rear gears:
http://www.csgnetwork.com/gearratcalc.html
And go to their main menu for other calculators:
http://www.csgnetwork.com/automotiveconverters.html
Good luck and c ya,
Sum
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Stan, Sumner, thank you for taking the time to reply. Based on your responses (as well as a couple of others I've gotten), I think that I will try to find a 28" tire to use - the SZ50s I have now have great wet traction, but I suspect that they'd be sub-optimal on the salt.
I'd be really happy to get 400 HP with the new heads/cam/intake combo, & absolutely blown away if I got anywhere near 425... (Keep in mind that I still have to pass emissions, which I suspect will limit my cam choices a bit...) I was thinking that 340 HP was a reasonable goal, & anything much over that would be gravy. Also, the more research I've been doing, it seems as though I need to worry about traction at least as much as power, so I've been trying to learn the best ways to apply the power without getting too squirrely...
And yeah, I figured I'd need to stay out of the OD gears, as I figured that the loss of "mechanical leverage" (for lack of a better term) would make it harder for me to push through the air... A friend of mine & I have been working the numbers, & based on our best calculations, after rolling resistance & aero drag, we're guessing that I should be able to manage an acceleration rate of about 5.28 ft/second - but that was based on making 330 HP (we had to guesstimate the rolling resistance of the tires, but we used two different methods to calculate aero drag converted to HP, & both methods were within 3 HP, so we think that part of it's reasonably close).
So far, I haven't been able to get any response at all from Comp Cams, despite twice sending them detailed info about my setup & what I hope/intend to do with it - but I'll post a query on one of the bigger F-body boards that I'm on, & someone will probably be able to give me the name of someone to contact who "knows their stuff" (I got bad info the one time I called in for advice). Is anyone here willing to suggest a good cam company to contact? My machine shop suggested Howard's cams, but I'd also like to hear what you guys think.
Anyway, once I get the cam narrowed down a bit, it would be nice if I could use the 3.42 gears, as then I could just bolt up a different rear end from another car, as that ratio came stock in a lot of the later cars, & would also save me some money on labor to set up the diff gears.
*THANKS AGAIN* for the help & the links guys!
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400 HP should not be a problem at all with those heads. I plugged some numbers into Desktop Dyno (not the best program, but it gets kind of close) and got the following.
With the AFR heads and the Tuned-port and a 12-412-8 comp cam that they recommend as a retro fit hyd. roller with a recommended 1200 to 5200 rpm range:
450 lb/ft at 4000 and 407 HP at 5500 (peak) still making 396 HP and 347 lb/ft at 6000. They say the cam is mild performance applications, very good mid-range, 3.23-3.73 gears. It is 212/218 duration at .050.
The next smaller cam, a 12-408-8, 206/212 at .050, 1000 to 5000 rpm makes 454 lb/ft at 4000 and 397 HP (peak) at 5500 with 379 lb/ft at the 5500. It is still making 377 HP and 330 lb/ft at 6000. This cam as sold as "strong torque, good mileage, and stock to mildly modified combinations.
Those good AFR heads will push the rpm limits a little above the advertised cam limits. I would love to have those heads on my truck. I think either of those cams would get the job done, but I got those out of their catalog that is a few years old. Try calling them or try Crane or Howard is good.
You might also want to try the "performance" board on Chevy talk. Some people on there a lot more knowledgeable than me:
http://www.chevytalk.org/threads/postlist.php?Cat=&Board=UBB64
c ya, Sum
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I may be wrong but, my 135 at maxton was reached 135 before 1/2 mile.
Just stayed on it to see if it would pull any more. How about going with 308 gears or more cam.
Howards cams are good cams for what your trying to do.
I would take a good look at the last cam Sumner listed.
Many years ago I read an aritical 86 camero ran 176 ,with 370hp aroun Daytona took 2 laps ,usad gta spoiler on back(89) not much more Ican rember C.R.S. Much luck Terry
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Wow - that's pretty encouraging guys! It's starting to sound like I'll have plenty of power to run the number (in fact, I'm actually starting to think in terms of "de-tuning" it a bit :shock: ) so I'll probably start to really work on the aero & chassis/tire part of the equation.
Terry, can you give any more details about your setup? I'd like to see how comparable yours is to mine...
Sumner, thanks *again* for the help. I'll hit the "Chevytalk" board when I have a bit more time to spare, thanks for the link. BTW, I love the page you've put together - I've had an interest lately in doing my own fabrication, & I've always had a weak spot for streamlined Studes! :D
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Try Dave's gearsplit program to help get your gearing right (shameless plug for his stuff follows):
http://www.enginemanagementsystems.com/gearsplit.html
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GTA drop the slow. Your car is a good start areo wise.
My truck is not much more than a 1st. gen camero. 327, the cam? 342 rear, turbo 350, stock converter,650 carb,accel hei dis. rpm (duel plain) intake, cool can for fuel line, electric moter for water pump 160-190 temps so far.tires 28 tall. 130 @ 5500 at 1/2 mile would not pull above 5800 135 mph.
My changes will be single plain intake 2" spacer,700 carb, 308 rear, msd 6a,these are for May , The cam is probley stock , what I told the builder475 to 490 lift 288-290 dur thats not there.
Much luck Terry
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Thanks Terry, I appreciate the reply. And since there seems to be a consensus about my nickname, I suppose I will change it - maybe to "SaltGTA"! :wink:
(The reason for the "slow" part of the name was because until recently, I didn't have the $$$ for the parts to make it quick, AND, even after my mods, I'm sure that I'll be slower than most of you guys! :lol: )
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Don't be so sure.