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-   -   I need better from a 17x33!!!!! (https://www.racingjunk.com/forums/showthread.php?t=22421)

supergass 12-02-2008 06:37 PM

I need better from a 17x33!!!!!
 
I have a 69 Camaro backhalf footbrake car. It weighs 3450 with me in it at 208. It has 1900lbs on the front and the balance on the rear for a wonderful weight dist. of 54.5 on the front with a 540 BBC. It is a ladderbar car set at 0degrees or level. I have afco double adjustable shocks up front (BNC) shocks (big nose compression) to controll the landing. I run the moroso front springs with great stored energy. I am just not so thrilled with my consistency. It runs 630s at 111mph. The 60ft is 1.42 with a 1.76 glide. I have M/T 17x33 with a huge 23 inch cross section and a super soft sidewall. I tried them after the 16x32 goodyears with a stiff sidewall. NOW the rub is my friends run 10.5 tires with close to the same ets and there cars are deadly consistent. THE only thing I can think of is my car seems to rev up a little at the shift point (not real firm) which might be why my mph is 5mph more at the same 60s and et. I wonder has anyone every seem such a thing?? The engine has tremendous torque, has anyone had clutch pack problems from the glide??

Thanks for any responses!!

dparker 12-02-2008 08:58 PM

Your engine on dragmath shows about 700 hp. I don't know where you think it should be. For a 3450 lb car I don't think I'd run soft sidewall tires. They're made for a dragster or light car. I think you need stiff sidewall tires on your application. Weight is the key. You have a heavy racecar its takes alot to get it going. I would need to know more to help you tune. Gear,stall,cam,heads,compression.

supergass 12-03-2008 05:54 AM

Great......the rear gear is a 4:56. The stall speed is 5000. The compression is10:1 and the heads are Brodix 320 CNC. When you say "I dont know where you think it should be" do you mean the ET? The reason I was concerned is that the mph is 4-5mph higher than most cars I run with for the same ET and same 60ft. Thought I may have a converter a little to tight or loosing et through transmission slippage. Thanks for your input

Chris

johnracer 12-04-2008 02:31 AM

I'd say you need more gear and more stall to get that heavy thing moving with a tire that big. Also, what tire pressure do run?

itsabird 12-04-2008 04:44 AM

60' times need to be better, soft-sidewall slicks and that kind of car weight is not a good match. i,m thinking the slick is wading up, and loseing traction, you can try more air, and stiffening rebound if you have double adj. shocks on the rear. pic or video would help, good luck.

dparker 12-04-2008 01:18 PM

No SG, a heavier car always has more mph than 60ft times. My truck runs 9.0s at at almost 150mph with a 1.29 60ft. When I run a comparable ET dragster. Their 60ft is around 1.19. A light car that runs a 10.00 will mph less than a heavy car running a 10.00. Your 10:1 540 putting out 700 hp is real good. I think everything you have is working properly. You probably can fine tune your car and pick up your times alot. I think a 1.80 straight cut plants would definatly help.
If you run any 1/4 mile I'd go with a 4:88 gear and if you race just 1/8 mile Id put a 5:14 gear in to get it moving. Those soft sidewall tires are killing your 3400 lb car. A set a stiff sidewall slicks wll help those 60ft times.

supergass 12-04-2008 02:18 PM

Thanks everybody, I used to run the Goodyear 16x32 before I went to the big mickeys. Mickey Thompson also makes a 16x32 stiff sidewall. I may go to it next. I also have a 5800 stall speed converter trans specialties spragless. The shorter tire and higher stall may come together in the right direction. BTW I ran about 7.5 to 8 lbs in the Big MTs to help them not cup in the center at launch.

RonOwensRacing 12-09-2008 03:30 PM

this car is 3563 lbs 540 engine power glide trans 1.80 straight cut gear set 6000 stahl converter 5.14 gear 33X16.5 X15 tires 1.28 60"s and runs 5.80"s in the 1/8 mile.

last 1/4 mile pass on the car it went 8.84

http://s76.photobucket.com/albums/j4...acing_0001.flv

flight71 12-20-2008 06:04 AM

Is that a vega that weighs 3500 lbs that seems heavy, does he have the truck filled with concrete???


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