Weight Mods...What You Think?
01-05-2011, 10:28 AM
#1
Safety Car
Thread Starter
Weight Mods...What You Think?
I had some ideas to remove some weight from the car and gain some hp up top. since my car has become less of a dd I was think of dropping some weight from it to see if I would get any real gains from it. First I was thinking of going with 23.5in long 3" dynomax bullet mufflers straight from the header collector with turndowns. This would mean zero backpressure from the exhaust and some free ponies up top in the power band but it would also mean a delete of the big 3" xpipe, the over axle muffler pipping and mufflers. The Hooker mufflers I have are at least 30-40lbs each. The mufflers plus all the pipping I figure should mean 80-100lbs. Also my ac comp went out a while ago, I have to remove it any way to reapir or replace it so why not just keep it off for now? Its been really cold and I went without it this past summer anyway plus its what, 30-40lbs? Im also looking at some Sparco and Hunsaker racing seats that should be lighter than the stockers. So, what do you guys think? I drag race and track the car but Ive been setting it more for HPDE and autocrossing. Also lets jsut say that loudness and no ac are not an issue for me already. That car is high compression with a big cam so Im use to noise. So would I be able to notice 150-200lbs off the car and the more free flowing exhaust? Btw, I shouldnt see any real "torque loss" down low with the new exhaust. The length of the headers (32in primary) should provide the necessary exhaust scavenging effect and no back pressure is always good. Also I weighed the car in at 3220lbs as is.
01-05-2011, 01:00 PM
#2
Race Director
any weight removal is usually a good thing, BUT the AC compressor doesn't weigh very much, and removing the exhaust from rear will actually hurt your balance. I think you'll see some gain, maybe not as much as if you could remove all of that weight up front.
01-05-2011, 02:18 PM
#3
Melting Slicks
David is right, front end weight is more important than rear end weight, but, if you drop weight you will see an acceleration gain all the way down the straight, and that counts for a lot. I'd look at getting a Z06 titanium exhaust. They flow well, are reasonably quiet on the street and weigh a lot less than what you have on the car. There are enough of them still around and you can get them for a reasonable price. Since they are from the cat back, the weight comes out from the entire exhaust system (although there is more gain in the back of the car).
The short pipes and turndowns can cause problems with heat on the rear springs. You need to be careful that you don't get the rear springs hot or they will fail.
Remember you have that big glass hatch, which gives you more rear end weight anyway, so taking some weight out of the back won't hurt you as much. That's the way I'd go if I were in your shoes.
The short pipes and turndowns can cause problems with heat on the rear springs. You need to be careful that you don't get the rear springs hot or they will fail.
Remember you have that big glass hatch, which gives you more rear end weight anyway, so taking some weight out of the back won't hurt you as much. That's the way I'd go if I were in your shoes.
01-05-2011, 02:23 PM
#4
Safety Car
Thread Starter
David is right, front end weight is more important than rear end weight, but, if you drop weight you will see an acceleration gain all the way down the straight, and that counts for a lot. I'd look at getting a Z06 titanium exhaust. They flow well, are reasonably quiet on the street and weigh a lot less than what you have on the car. There are enough of them still around and you can get them for a reasonable price. Since they are from the cat back, the weight comes out from the entire exhaust system (although there is more gain in the back of the car).
The short pipes and turndowns can cause problems with heat on the rear springs. You need to be careful that you don't get the rear springs hot or they will fail.
Remember you have that big glass hatch, which gives you more rear end weight anyway, so taking some weight out of the back won't hurt you as much. That's the way I'd go if I were in your shoes.
The short pipes and turndowns can cause problems with heat on the rear springs. You need to be careful that you don't get the rear springs hot or they will fail.
Remember you have that big glass hatch, which gives you more rear end weight anyway, so taking some weight out of the back won't hurt you as much. That's the way I'd go if I were in your shoes.
Im wondering too to remove the condenser since i wont have ac. I know its not too heavy but will I see better air flow or better cooling across the radiator?
01-05-2011, 02:37 PM
#5
Racer
01-05-2011, 03:45 PM
#6
Melting Slicks
Ending the exhaust under the car like that is a prescription for gassing yourself out on the highway. In a race car it isn't a big deal because the windows are always open. In a street car it can be dangerous because you can and will keep the windows closed a lot more.
Insulation is worthless unless you have a way of removing the heat from the spring. Just because you have insulated it, doesn't mean it won't get hot, it just means that it won't get hot fast. There isn't as much air under these cars as there was in times past, so you have the potential to have a lot of exhaust gas under the car.
In many states exhaust pipes under the car like that are illegal as well as dangerous. I'd make sure you have an exhaust to the rear of the car, or pipe it out to the sides ahead of the rear wheels and keep it out from under the car. With a Z06 Ti system only costing around $300, what's the problem?
Insulation is worthless unless you have a way of removing the heat from the spring. Just because you have insulated it, doesn't mean it won't get hot, it just means that it won't get hot fast. There isn't as much air under these cars as there was in times past, so you have the potential to have a lot of exhaust gas under the car.
In many states exhaust pipes under the car like that are illegal as well as dangerous. I'd make sure you have an exhaust to the rear of the car, or pipe it out to the sides ahead of the rear wheels and keep it out from under the car. With a Z06 Ti system only costing around $300, what's the problem?
01-05-2011, 07:13 PM
#7
Safety Car
Thread Starter
Ending the exhaust under the car like that is a prescription for gassing yourself out on the highway. In a race car it isn't a big deal because the windows are always open. In a street car it can be dangerous because you can and will keep the windows closed a lot more.
Insulation is worthless unless you have a way of removing the heat from the spring. Just because you have insulated it, doesn't mean it won't get hot, it just means that it won't get hot fast. There isn't as much air under these cars as there was in times past, so you have the potential to have a lot of exhaust gas under the car.
In many states exhaust pipes under the car like that are illegal as well as dangerous. I'd make sure you have an exhaust to the rear of the car, or pipe it out to the sides ahead of the rear wheels and keep it out from under the car. With a Z06 Ti system only costing around $300, what's the problem?
Insulation is worthless unless you have a way of removing the heat from the spring. Just because you have insulated it, doesn't mean it won't get hot, it just means that it won't get hot fast. There isn't as much air under these cars as there was in times past, so you have the potential to have a lot of exhaust gas under the car.
In many states exhaust pipes under the car like that are illegal as well as dangerous. I'd make sure you have an exhaust to the rear of the car, or pipe it out to the sides ahead of the rear wheels and keep it out from under the car. With a Z06 Ti system only costing around $300, what's the problem?
Last edited by C5Natie; 01-05-2011 at 07:19 PM.
01-05-2011, 07:34 PM
#8
Le Mans Master
01-06-2011, 07:20 AM
#11
Team Owner
Ending the exhaust under the car like that is a prescription for gassing yourself out on the highway. In a race car it isn't a big deal because the windows are always open. In a street car it can be dangerous because you can and will keep the windows closed a lot more.
Insulation is worthless unless you have a way of removing the heat from the spring. Just because you have insulated it, doesn't mean it won't get hot, it just means that it won't get hot fast. There isn't as much air under these cars as there was in times past, so you have the potential to have a lot of exhaust gas under the car.
In many states exhaust pipes under the car like that are illegal as well as dangerous. I'd make sure you have an exhaust to the rear of the car, or pipe it out to the sides ahead of the rear wheels and keep it out from under the car. With a Z06 Ti system only costing around $300, what's the problem?
Insulation is worthless unless you have a way of removing the heat from the spring. Just because you have insulated it, doesn't mean it won't get hot, it just means that it won't get hot fast. There isn't as much air under these cars as there was in times past, so you have the potential to have a lot of exhaust gas under the car.
In many states exhaust pipes under the car like that are illegal as well as dangerous. I'd make sure you have an exhaust to the rear of the car, or pipe it out to the sides ahead of the rear wheels and keep it out from under the car. With a Z06 Ti system only costing around $300, what's the problem?
01-06-2011, 10:06 AM
#12
Safety Car
Thread Starter
You guys do know that as you drive air does flow under the car dont you? I drove my GTA Firebird with a similar setup for years.....maybe Im still asleep. lol. Did I post that I was running a garden hose from the muffler to the cabin somewhere?
Last edited by C5Natie; 01-06-2011 at 10:08 AM.
01-06-2011, 01:08 PM
#14
Team Owner
Carbon monoxide poisoning occurs after enough inhalation of carbon monoxide (CO). Carbon monoxide is a toxic gas, but, being colorless, odorless, tasteless, and non-irritating, it is very difficult for people to detect.
I drove my GTA Firebird with a similar setup for years.....maybe Im still asleep.
Last edited by John Shiels; 01-06-2011 at 01:18 PM.
01-06-2011, 05:03 PM
#15
Melting Slicks
John has explained it well, as have others, that what you are proposing is not only stupid, but it is dangerous. The amount of air moving under these cars is nowhere near as great as it is in many other cars, and as we all know these cars are not sealed well at all.
Exhaust leaking up through the tunnel, around the shifter and from areas around the wheel wells is a dangerous thing. In a race car with open windows, on the track, you could get away with it, but on a rainy day with the windows shut and stuck in traffic it is a potential death trap.
With modern emission control and converters, you won't smell a thing before you pass out. Not sure, but I was thinking that even the SCCA would not allow exhausts under the car ahead of the rear axle. If they come out the side it is ok, but doing what you are talking about is, as noted above, illegal in many states for this very reason.
I have a hard time understanding why you seem to be stuck on doing something that is so stupid and dangerous.
Exhaust leaking up through the tunnel, around the shifter and from areas around the wheel wells is a dangerous thing. In a race car with open windows, on the track, you could get away with it, but on a rainy day with the windows shut and stuck in traffic it is a potential death trap.
With modern emission control and converters, you won't smell a thing before you pass out. Not sure, but I was thinking that even the SCCA would not allow exhausts under the car ahead of the rear axle. If they come out the side it is ok, but doing what you are talking about is, as noted above, illegal in many states for this very reason.
I have a hard time understanding why you seem to be stuck on doing something that is so stupid and dangerous.
01-06-2011, 05:19 PM
#16
Team Owner
Plus cutting weight as low as an exhaust system is less beneficial as cutting weight from a windshield or something with a higher CG.
01-06-2011, 05:27 PM
#18
Racer
with these cars, concentrating from the windshield forward is key. they are already nose heavy. LT's would be near the top of the list, center piping and mufflers would be last. I have 66 lbs of ballast just a few inches above the H pipe. The H pipe is as low on the car as you can get, and closest to the center of gravity. That's right where you want it.
01-10-2011, 10:40 AM
#19
Safety Car
Thread Starter
Well it might be in my head but seems like without the ac compressor and tensioner setup the motor spins up a bit quicker. I can feel it rev up a bit faster even if I barely give it some throttle. I could see how the compressor pulley with a tensioner as well could create some drag. Also without the condenser the car has been running about 20+*F cooler. Before when the coolant temp was usually about 185-195. Without the cond its been no higher than 171-174, even when I would get on it. stopped for 10min at the store, started it back up, coolant was 185 and within 3min of street driving it was down to 171 again. This is great for me because that should mean lower cc temps= less/no detonation or retarded timing especially since Im high compression. Btw I run distilled water with 2 bottles of water wetter. Seems to be working great for me.
__________________
To address the exhast issue, I decised to run the xpipe with 20" dynomax ultra flos at the end with turndowns so it should terminate right before the trans cradle but point down so it wont heat up the leaf spring. Also the mufflers will be wrapped with header wrap to help insulate against radiant heat.
__________________
To address the exhast issue, I decised to run the xpipe with 20" dynomax ultra flos at the end with turndowns so it should terminate right before the trans cradle but point down so it wont heat up the leaf spring. Also the mufflers will be wrapped with header wrap to help insulate against radiant heat.
