Star79

Last year I ran 14.23 @ 96.6

I'm gonna try next month with the following changes:

Skinnier front tires (225 instead of 245) with 45+ lbs of air in them.
At least 75 pounds less weight in the car (spare-delete, no tools/jack/etc in the car this time, me on a diet)
Unhook the exhaust from the headers (2 1/2" true duals with turbo mufflers, so not much restriction anyway...)
Fresh synthetic oil.

Think I'll drop into the 13s, even barely? Any other tips I might try that don't require spending any money?

Specs:

100,000+ mile L-48, stock bottom end cam and heads
Headers 2 1/2" duals MidAmerica turbo mufflers
RPM intake with 3/4" spacer and q-jet
Lars' recurve 8MM wires Accel supercoil on stock HEI
700r4 stock converter 3.55 gears 255/60-15 BFG T/As

Thanks!

The3

Remove the front sway bar?

ajrothm

1) Remove front sway bar
2) Run a single short belt around only the fan/water pump and alternator bypassing everything else
3) Remove air cleaner
4) Stock converter---get up on the converter as much as possible that will allow WOT out of the hole without spinning.
5) Run as much air pressure that will still allow it to hook.
6) Allow engine to cool as much as possible before runs and push through the lanes.


A stall converter would work WONDERS in that car. Best $500-600 you could spend. It would give you .5 tenths reduction EASILY, probably more like 7-8 tenths.


Your car is running pretty good though for no more mods then what you have. My 71 with a stock low comp smog motor has only gone 15.0s@91 with headers, 2.5" exhaust and stock th400/3.08s. I am hoping for 14.90s next time out with my change to the Performer intake(from iron stock) and new summit mech fuel pump.

Z-man

Lose the fan and the passenger seat too. Keep the lower plate of the air cleaner after removing the air filter.

jdunne

try it with half a tank or less of fuel....that will save another 50+llbs...john

Star79

Last time at the track I had around 1/4 tank.

Thanks I'll try all that stuff, except the NEW converter, I know it would make a big difference but I can't spend any money at the moment. I already load up the converter as much as possible (maybe 1300-1400 rpms). I'll have to see how hot the car gets idling without the fan.

Thanks, I'll get back with times when the track opens and the car is ready

Glensgages

I don't think the different front tires will help you much 'weight-wise', but I believe they'll be about an inch taller, providing you w/ more roll-out if you stage as shallow as possible, and this may 'trick' the clocks into giving you a quicker ET-card.


After removing the air-cleaner, if you can fabricate an air-pan/box, sealing the carb to either the under-side of the cowl-induction hood (to get fresh-air from the base of the windshield ), or the pair of ducts in your hood (if they are functional ), that little bit of fresh-air may help push you into the 13s.


Do you run at Sanair?

ajrothm

Star 79, your fan will still be operational. Just run the belt around the crank/water pump/alternator. That way you still have the charging system working getting voltage strong for the ignition and the fan still works. Its the PS and AC that really soaks up the power. BUT you could gain more power if you took the fan off and just put nuts on the pulley and just power the water pump and alternator. Not sure how much a clutch fan kills, maybe 8-10 crank HP but when you are looking for everything you can get...its an idea but probably not worth the hassle.

Also that is a good idea about leaving the air cleaner base on but removing just the lid. I never thought about that but it would help keep it from sucking in heat right off the intake etc.

What I would do if I were you, if ENTIRELY possible....get a Hughes GM25 stall converter. Its a 2500 stall and is only around $160.. Its a good quality converter for the money and I bet would give you .3 tenths if not more. Just a little work to jerk out your tranny and stick it in there. Not sure if that converter works on a 700R tranny though..

You can try uncapping the exhaust but I doubt you will get anything out of it...in reality it might hurt your launch some because you will lose some bottom end tq and with no converter to make it up, it might hurt more then it helps.

oregonsharkman

Try packing some ice/blue ice bags around the manifold while in the stagging lanes. Take them off right before your burnout. I have seen many racers do this down at woodburn dragstrip.

good luck and keep us posted on your results.

lars

If you uncork the headers, bump your primary jet size up 2 sizes. That'll probably get you the 2 tenths right there.

C3 4ME

I have always heard that evey 100 lbs lost equals about 1 tenth, so you might be close just with the weight savings.

hugie82

It doesn't sound like you have a traction problem so I'm going to say a electric fan set up is worth at least 15hp+ and for $250 you can have a dual flex a lite that fits right in. Also a set of ultralite center line rims off ebay couldn't hurt either. and if you have a mild or stock cam a set of 1.6 rocker arm will work but check the valve stem for build up. If you have carbon build up you have to remove the valve spring and clean it so you don't ruin your valve guide and seals.

toddalin

Do all of that stuff AND run in the dead of winter on the coldest day of the year. That could do it.

GrandSportC3

He could take the mechanical fan off just for the run.... No need to buy electric fans.. The engine will not overheat during the run as it's cooled from the higher speed.. He just will have to put the fan back on when driving back home..
The mechanical fan is worth at least a tenth if you are running in the 14's..
100 lbs weight savings is worth another tenth.. Open exhaust can be worth as much as 3 tenths but will be more likely about 1 tenth. However, the A/F might have to be tuned for open exhaust to get the best possible result..

gkull

Junk that mech big clutch fan and install a 17.5 inch 10,000 rpm Stainless steel. Get rid of all the weight you can. You did not say what kind of heads. But with Vacuum advance off ensure that you have a max timing of say 38 degrees when you have the motor turning 3500 rpm. That is enough rpm to make sure that it is all in.

IMO - air pressure tips. Run the front at max. If it says 35 max run 35# additional is minimal gains. Rear - Don't listen to the bench racers about super low pressure giving your rears more bite. You use the pressure that maintians equal pressure accross the tire face of the tread. It is usually achived within 4-7 pounds under max pressure.

figure out how high of rpm that you can power brake before your motor overcomes the rear brakes. this might only be 1500 or so rpm.

Play with the shift points. try up near your red line and then in 200 rpm increments lower to find your best ET. If you just want the best time, shallow stage so you can already be moving when you break the start time light beam

MotorHead

"100,000+ mile L-48, stock bottom end cam and heads"

Does that mean stock cam and heads ?

If so I am amazed it got up to 96MPH period, let alone in the 1/4 mile

Artsvette73

Work on you reaction time

GrandSportC3

The reaction time has nothing to do with ET... It's a separate number and not part of your time..

Star79

yup, stock cam and heads. In fact when I put a new timing chain and gears on last summer the original plastic gear was still there (along with about 2 inches of slack in the chain...)

I'll try every tip in here that doesn't cost anything, I'm going to see how fast I can go before major expenses (cam/heads/converter are in the plans).

And I don't have traction problems at all, especially on a sticky 1/4 mile track.

Glen, yes it was Sanair where I ran last October, and that's where I'll try to do 13s next month. It'll probably still be pretty cold out.

SpyderD

Suprised no one came up with the obvious answer to drastically improving 1/4 mile time - improve 60 foot time. Get drag radials and you will probably be there.

Now we don't know what you have or haven't done, we can only speculate - but I would say, not counting drag radials, experiment with leaving at a higher RPM or shifting at a higher or lower RPM to shift at your exact power points.