Hit a corner scale Sunday

[My_Coyote]

Carbon fiber drive shaft and GT350 rims is where you can remove some fat

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[Norm Peterson]

Remember rotational weight is also worth a lot more then dead weight. I have heard some say that every pound of rotational weight is worth 10 pounds of dead weight.

It's not a fixed ratio like that for all rotating weight, and for wheels, tires, and brake rotors it's usually quite a bit less, maybe more like 2 to 1. Maybe for a flywheel on a car with deep overall gearing instead???


Norm

 

[bluebeastsrt]

2 to 1 sounds reasonable. Changing out the stock wheels and tires for skinnies and light weight wheels. nets about a 1/10 improvement at the drag strip.

 

[Bartly]

So here is one since we are talking weight. So most of the FI kits seem to add somewhere around 100lbs (the procharger kit was 131 shipping weight) to the engine compartment. Wondering what does to the GTs front/rear weight distribution. Cant be helping out with wheel spin. How does one combat that? Does it start with pouring a little cement in the spare tire well, lol.

 

[Lonmon]

I will agree that I doubt it is actually a 1:10 but flywheel, drive shaft and rear wheel and tires can allow more power to the wheels as well as actual weight reduction. I did say "I have heard some people say", not it is a known fact. That being said if wheels and tires can knock off a tenth, that should at least amount to 100lbs or so for a 30-50lb actual weight reduction. So 1:2 is probably a pretty safe assumption. I think we can all agree that double is pretty good.

As far as adding weight with FI, adding 100lbs is nothing compared to adding 200+whp. The car will probably be better balanced for track racing without the extra 100lbs up front but for a drag car the suspension setup can help with weight distribution for launch. Just look at the results, most FI guys are killing it with these cars. If a drag monster is what your after FI is certainly the way to go. I just don't want a roll cage in my car so low 11's with a potential for high 10's is good for me at this point.

 

[Norm Peterson]

So here is one since we are talking weight. So most of the FI kits seem to add somewhere around 100lbs (the procharger kit was 131 shipping weight) to the engine compartment. Wondering what does to the GTs front/rear weight distribution. Cant be helping out with wheel spin. How does one combat that? Does it start with pouring a little cement in the spare tire well, lol.

Front weight goes up by 1% or a bit more (something like 54.0/46.0 → 55.3/44.7 for 100# added directly over the front axle line). All else the same, breaking the rear tires loose would of course come more easily.

At the dragstrip you have whatever starting line prep was done, plus some intentional tire cleaning/heating, on drag radials (or better) that you hopefully didn't heat-cycle to death in street driving. Those things don't correct the less advantageous weight distribution; they only enable better use of the less rear weight than you can make with more rear weight and not doing those things (IOW, the usual street situation).


Norm

 

[Bartly]

Front weight goes up by 1% or a bit more (something like 54.0/46.0 → 55.3/44.7 for 100# added directly over the front axle line). All else the same, breaking the rear tires loose would of course come more easily.

At the dragstrip you have whatever starting line prep was done, plus some intentional tire cleaning/heating, on drag radials (or better) that you hopefully didn't heat-cycle to death in street driving. Those things don't correct the less advantageous weight distribution; they only enable better use of the less rear weight than you can make with more rear weight and not doing those things (IOW, the usual street situation).


Norm

Curious you didn't mention changing suspension to reduce wheel spin at the dragstip like others have suggested, but focused on tires and track prep. What are your thoughts on adding weight to the trunk. I know, I know weight reduction is the key, but would think if adding 100 lbs in the front doesn't have a dramatic effect for the kind of power FI delivers, would think adding another 100 in the trunk would only lessen wheel spin which should improve times. Just thinking this sounds crazy to me, can't believe I'm even asking, just have readnyour posts and you appear to have some good insight and experience with cars/racing so I thought I'd ask.

 

[bluebeastsrt]

Curious you didn't mention changing suspension to reduce wheel spin at the dragstip like others have suggested, but focused on tires and track prep. What are your thoughts on adding weight to the trunk. I know, I know weight reduction is the key, but would think if adding 100 lbs in the front doesn't have a dramatic effect for the kind of power FI delivers, would think adding another 100 in the trunk would only lessen wheel spin which should improve times. Just thinking this sounds crazy to me, can't believe I'm even asking, just have readnyour posts and you appear to have some good insight and experience with cars/racing so I thought I'd ask.

Never ad weight to a drag car. It will make you slower. Try getting some adjustable shocks. With a lighter spring. Set the front damper to it's softest setting. That will allow the front of the car to lift and load the rear suspension and tires. Set the rebound on the front shocks to a medium setting so they don't rebound to quickly. Suspension tuning takes some patience. But it will reward you.

 

[Chameleon]

Carbon fiber drive shaft and GT350 rims is where you can remove some fat

Yeah that Carbon fiber DS is so damn expensive! Still want it though.

 

[5ABI VT]

Nice ! I weighed everything i swapped out i just did wheels and suspension and cat back so far and have shed quite a bit on my base pp w/recaros. Corsa drops a significant amount over stock and my coilovers were another 40 lbs.

 

[EFI]

I have to ask since this plan is kinda boggling my mind.

What was the purpose of getting the performance pack if 1) you're more interested in drag racing and 2) you're taking off all the PP parts anyway and replacing them with lightweight stuff or not at all

Wouldn't it have been easier and cheaper to just buy a base GT with the base brakes and no bracing?

But that's just me. I wouldn't spend all that money on fancy Brembo brakes and bracing to then remove them.

 

[Norm Peterson]

Curious you didn't mention changing suspension to reduce wheel spin at the dragstip like others have suggested, but focused on tires and track prep.

Because wheel spin is ultimately a function of tires and pavement. With only corner weights to go on, the topic hasn't developed far enough to go much deeper. Not even any mention of wheel hop yet, and since this is an IRS car at least one of the go-to solutions for a stick axle drag car no longer applies.

would think adding another 100 in the trunk would only lessen wheel spin which should improve times.

Added weight will hurt you over every inch of the way that the car is hooked up. You might end up paying for a 3% improvement in acceleration over the first 60' with 2.5% slower acceleration everywhere else. Win-lose for the overall loss.


Norm

 

[Norm Peterson]

What was the purpose of getting the performance pack if 1) you're more interested in drag racing and 2) you're taking off all the PP parts anyway and replacing them with lightweight stuff or not at all

Decision to focus on drag racing came after the purchase.

When I bought the car I wanted many of the advantages of the PP. The bigger radiator, 373 gearing (planning on staying NA), spoiler delete with no holes left in the trunk, wheels (at the time), gauges, and bigger brakes (at the time). Yes the bracing, springs, and sway bars are different as well. I thought I may try some autocross or something and figured I may like the handling improvements. Then as time went by I realized that any kind of track racing can get a lot more expensive then the occasional run down the drag strip. I am a drag racer at heart

Norm

 

[Stroked89coupe]

Another 55lb weight reduction this weekend!

How are those brakes working out for you? Assuming you went this route to run a 15'' wheel setup?

 

[NoVaGT]

Holy thread resurrection!!!

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