I'm talking about my '68...
Since the last time at the track - I did following mods:

Race seat (20 lbs weight saving)
Skinny front wheels & tires(25 lbs centrifugal weight saving)
ET Streets on lightweight wheels instead of Drag Radials on heavier rims (26 lbs centrifugal weight saving)

In addition - I will also get following mods:

Carbon Fiber Driveshaft and Half Shafts.. (1/2 the weight of the steel shafts)
Electric fuel pump

So - what can I realisticly expect from those mods??



[Modified by GrandSportC3, 8:46 AM 8/21/2003]

 

nobody??

 

Very little. Maybe .03 to .05 but thats will depend more on weather conditions.

 

I always thought that the centrifugal weight is worth 3 - 5 times tha actual weight saving... :confused: :confused: and the 100 lbs of effective weight saving should be a .1 better ET... Well - that theory might be wrong...

I also remember reading about people getting .1 better ET just by switching to skinnies front runners...


[Modified by GrandSportC3, 12:31 PM 8/21/2003]

 

I'am going to be alittle more optimistic. I predict a full .1 (one tenth) of a second.
Good Luck

 

I was actually expecting around .15 or so... Will see...

 

im sure you will do better then a tenth. you are getting better tires and skinnies. Just that should do a tenth. the weight savings are gonna help to. Im sure you will get your 11 second pass :yesnod:

 

Just 11's won't be good enough for me.. I should be in the 11's just by having a good pass with good traction... When I ran 12.06 - I had a 60' time that was over a tenth slower than what I get on a good track.. so I would have been already in the 11's.. I want to get AT LEAST to 11.80's... or maybe even into high 11.70's...

 

I think in cool weather you should be able to come close

 

I'm only going to race again with temps below 70 degrees...

 

same here

 

Don't you race the Corvette Challenge??

 

i do but im takin a little break. cash is low

 

Just win and cash in on the prize money :D :D :D

 

.05 to .10 in the 1/4. Probably closer to .05.

Regards,

Mark

 

Oliver, The only way you can tell how much better you do with those or any other minor changes is for you to keep records of your runs as far as weather, track conditions, etc. and log all that and run the car in very similar conditions and then you can compare. Also don't forget your running a 4-speed, there will be some inconsistancies no matter how good you are. You can be a tenth off just by the way you shift on a particular pass. You want to see a signifcant improvement? HORSEPOWER!!!! :D

 

I actually have a 5-speed and not a 4-speed :D :D
I understand that the conditions will affect my ET's.. I had my best ET so far in 65 degrees weather with low humidity (12.06)... I have decided not to increase the HP output of the engine because I don't want to break more things on the car.. Too much stuff broke already and cost me big $$.. so I don't want to risk breaking more stuff.. I try to get the best possible ET without actually touching the engine...

 

With the front skinnies only saving you 20 lbs, you are either running a heavy skinnie radial or your old front street tires were pretty light. On a C4, the stock rim and radial is typically right around 50 lbs, and a lightweight weld 15 x 4.5" rim with a MT front tire is going to be right around 20-22 lbs, thus a savings of just about 60 lbs, which is worth a solid tenth without a doubt. However, if you have a heavy MT Sportsman front radial.... then each front skinnie can weight 35-40 lbs, which of course you will only see maybe 1/2 tenth et improvement at best.

Your 20 lb racing seat should be worth .02 or so.

A 26 lb savings on those rear wheels is huge, you should see a solid 1/2 tenth from that and maybe even more....and you should be able to launch your car harder and more consistent with the ET streets, thus maybe even more et improvement. But also keep in mind, ET streets will cost you roughly 1/2 mile or so versus a radial due to the added resistance going down the track.... but I still think you should get at least 1/2 tenth on this modification.

Not sure on your driveshafts... could be a hundredths or two there I guess...

I think on average you'll be quicker by 1 to 1.5 tenths, but you may not see it initially.... weather can easily fool you into seeing no gain.

good luck
Beach Bum

 

I currently use Centerline Auto Drags 15 x 8.5 with 255/50R15 BFG Radial TA's in front. The rim weights 14.5 lbs and the tire 27 lbs which results in a total weight of 41.5 lbs per rim. The skinnies have 29 lbs each(rim + tire). I'm also using a wheel adapter which has 2 - 3 lbs... so my total weight savings is approx. 10 lbs/rim...


[Modified by GrandSportC3, 12:48 AM 8/23/2003]

 

i cant imagine a 41 pound wheel and tire :crazy: I think mine weigh half that