Removed material from the bumpers before chrome plating???? I assume you used the new light weight chrome and those must have been some very heavy bumpers to begin with. 2600 lbs. ????

 

racervette, i'm interested in the lightweight body you've got...i'm following the same path as you, i've got little left too but the body is still stock...thanks for your indications

 

following your calculator i should be at 2.00 sec from standing to 60 mph...not a bad light to light challenger at all

 

An automatic is easier to get off the line without wheel spin. Maybe install a 200R4.

You could move the battery to the rear of the storage compartment on the passenger side for better weight distribution and balance.

Remove the front sway bar and make the front control arm bushings slightly oversize to get the maximum amount of lift.

Go to the tallest front springs you can find.

Drop the inner strut rod mount on the rear suspension to make the half shaft and the strut rod parallel. There will be no camber change when the rear suspension squats.

BigBlockk

Later.....

 

ok took the conversion program out - my car weights 1270KG that is 2799lb sorry for the confusion, i was under the impression that lb was roughly kgx2

No need to be a smart hat Alan i metioned the bumbers to illustrate that i shaved off lots of weight all the small things combined.
and i took excatly 4kg = 8.8lb off the bumpers


Thank you Bigblockk thats some solid advice.

 

PNK,
I was making a little joke referring to the fact that you seem to have
tried to think of EVERY weight saving possibilty.
Regards,
Alan

 

If your considering all the work and expense of changing frames
buy something or just modify your frame that allows you to
in set bigger tires. Probably cause problems if you want to
keep the convertible top frame in the car.

 

That calculator is way off on good hooking cars.. 1/8 mile ET and mph is not really a good indication of 0 - 60 mph..

I know cars that run mid 6's in the 1/8 mile at about 105 mph and their 60' time is 1.35.. That means that they hit 60 mph after 1.35 seconds.. However, their 1/8 mile ET+ mph only shows 2.12 seconds.. That's a huge difference.. I 60' at 1.39 - 1.40 and I'm at 58.8 mph at the 60' mark based on the calculation.. It's not taking me another second to 60 mph... Therefore, my 0 - 60 mph estmation is about 1.5 - 1.6 seconds with my old setup..

 

another thing.. The semi-coilovers are great for road racing and handling but THEY WILL HURT YOUR 0 - 60 time! At your power level and tires size, YOU WILL NEED ALL THE WEIGHT TRANSFER IN FRONT THAT YOU CAN GET!! Coilovers or semi-coilovers will not get you that weight transfer.. Also, any front spring ratio of 300 lbs/inch or higher will also hurt your acceleration. Softer springs release the engergy slower and also expand more and that brings the front up highter.

I've been through all that to make my car hook and I know what I'm talking about. I have one of the hardest hooking C3's out there.. Soft front with 90/10's and stiff rear with QA1's (which you already have). I'd set the rear QA1's to about 10 clicks!



Here's my suspension setup:

213 lbs/inch Moroso Trick front springs (with 2 coils cut off = 250 lbs/inch final ratio)
Competition Engineering adjustable 90/10 shocks - set to 90/10
550 lbs/inch composite rear spring
QA1 rear shocks set to 10 - 11 clicks
All my launches are within 2 hundreds of a second.

My car is also about 2800 lbs (maybe slightly under without the nitrous bottle and slightly over with the full nitrous bottle)

There are some super cars that run 3.2 - 3.7 seconds 0 - 60 mph on street tires BUT most of them have the engine in the rear which really helps traction. Those times are also usually achieved at the drag strip where they have VHT on the track.. I HIGHLY doubt that you can actually get anywhere close to those times on the street in ANY car with street tires on the street..

 

I am not sure what you are trying to say. Are you saying that what ever your 60' time that is how long it takes you car to go from 0-60? if so you are incorrect.

I tried, but could not figure out the rest of what you are trying to explain with 2.12 seconds and your car at 58.8 and taking another second to go to 60 mph ????

60' times are only that.........0-60 feet, there is no correlation to a mph matching (on a linear scale) the time it takes your car to go to from 0-60 feet.

 

That's not what I'm trying to say.. I'm just trying to say that the 0 - 60 mph calculation on that site is inaccurate.

I just ESTIMATED my 0 - 60 mph time to be about 1.5 - 1.6 seconds as my best 60' time was 1.39. The mph calculator from the 60' time shows that I'm at 58.6 mph at the 60' mark in 1.39 seconds.. I should be able to pick up the additional 1.4 mph in less than 2 tenths which would put me in the 1.5 - 1.6 second range for 0 - 60 mph.
It's commonly known that a 1.35 60' time puts you at 60 mph at the 60' mark and I know someone that hits 1.35 60' times but only runs about 6.50 @105 mph in the 1/8 mile. Based on the 60' calculation, his 60' time puts him at 60 mph at the 60' mark after 1.35 seconds. The 0 - 60 mph calculation from his 1/8 mile stats calculates his 0 - 60 mph time to be 2.12 seconds. The 1/8 mile / 0 - 60 mph calculation is inaccurate for hard hooking vehicles! That's what I was trying to say..

 

Ok, I have never heard that a 1.35 60' is 60 mph at the 60' beams. As for the rest I think I get your point.

 

Fair enough Alan there should always be room for a joke, i just took it the wrong way

LittleMouse - i agree, the frames i have been looking at are all setup for C4 or C5 suspension with much wider tirewalls.

Grandsport - thank you for the detailed setup description i can see that one of my first improvements have to be to loosen up that front end as you and others have pointed out, i think ill do 1 thing at a time and see where it takes me.

Here is my plan with runs in bewteen each modification.
take off the semicoilovers and put in some 250 lb springs
and change front shocks to some 9/10s

change rearend to 3.08 and up my revlimiter to 7k preferrably hitting 60 in first.

Get some stickier tyres, have to look up what my options are for 20" rims.

try some runs with near empty tank and some with full tank, if the full tank works better then i prolly have to put on some meat in the back.

If there is no change with this combined, then my winter project is probably gonna be a new frame with a C5 setup.

Thank you for the help everyone i will keep you posted on my progress or failures it will be a month or so before i have the time, im off to Disneyland in Paris with the family for the next couple of weeks.

 

That's also what the 60' mph calculator comes up with and I've been talking about that with other racers and it seems to be commonly known/assumed that you are at 60 mph at the 60' mark with a 1.35 60' time.. I don't know if it's true but I've heared that from several sources..

 

One thing that you have to be VERY careful about is the 90/10 front shocks.. Unless you make a acceleration run, set the adjustable 90/10s to 60/40. Street driving (curves) can be very tricky with the shocks set to 90/10.

However, if you want the best possible acceleration, you will need them set to 90/10 but your handling in corners will suffer.
Another option are the QA1 front shocks.. The expansion on those shocks has to be set to the lowest resistence (1 click) for best results. However, the QA1's are about 2 - 3 times more than the Competition Engineering 90/10's..
BTW - taller rims = less traction. What gives you traction is taller sidewall and if you have tall rims, you have less sidewall.
For example, I have had 1.80 60' times at the track with 28 inch tall street tires with 15 inch rims (tall sidewall) but I've never been below 1.95 60' times with 26 inch tall street tires on 17 inch tall wheels.. The reduced sidewall definetely hurts traction but helps handling..

I doubt that there are any sticky tires available for 20' tall rims.. If you REALLY want to hit the 3 seconds, I'd recommend to get a inexpensive set of 15' wheels with Mickey Thompson Drag Radials 275/60R15

BTW, the C5 frame and suspension is actually a disadvantage for acceleration as the composite front spring doesn't allow the front to lift too much.. C5 suspension is much better suited for road racing..