Excess metal removal

[jdub]

Unfortunately, prozac is something I have experience with...

That is obvious. (sorry - but the responses IJ quoted just do not make sense)

Rather, based on the input given I will likely remove the peice aforementioned and take whatever consequences that follow. But I will weigh the peice if not more than to prove it past 6 pounds.

Looks like you had your mind made up to begin with, so why even ask? My opinion is that cross member is structural...most likely there to stiffen the frame against twist/side loads and (more important) reinforcement to the frame to provide crash integrity. Like I said, the weight savings is just not worth it IMO.

 

[Supracentral]

Back in 2004, at the Texas Supra Nationals, there was a fender bender outside of the Texas World Speedway.

There was a MKIII (with similar "metal removal" as what you decribe) that rear ended a MKIV. This was a very low speed accident. The MKIV had some chipped paint on the bumper.

Most of the "damage" you see above is paint from the MKIII stuck to the bumper.

The MKIII however was a mess. Here's the car:

If the owner of this car is on here, please speak up.

The radiator was touching the motor. The fan was through the rad. The water pump was physically broken by the impact, the crank pulley was cracked, the timing tensioner was broken, the frame was tweaked. And that's just what we could see standing on the side of the road. That car went back to Dallas on a flatbed.

Now is it structural from the perspective that the cabin will fold up and kill you in a wreck? Probably not. But it does provide rigidity in the frame, and helps a very small fender bender from being a multi-thousand dollar wreck. If performance is your goal, there are better options.

You're dealing with a unibody car. It doesn't have a full frame. That piece of metal is what keeps the two sides of the forward subframe assembly parallel. Any off center impact to the front of the car is going to tweak the froward frame rails.

I've gotten a drag Supra down to 2,900 lbs (with driver and fuel) and I've never removed structural members like that. And this is in a car that would never see the street, nor would it ever have a "minor" impact.

There are a ton of places you can take weight out of these cars other than slicing up the subframe assemblies.

Take a look at the MKIV Hardtop Registry that is also hosted on this server. Even though it's MKIV oriented, it can give you an idea of where to save weight:

http://www.suprahardtopregistry.com/ (Click the 2nd link which says weight reduction).

You won't find a group of people more interested in weight reduction than MKIV hardtoppers. (I know, I'm one of them...)

But we use sanity when doing this stuff. Your idea is, in my opinion, not a wise one.

Your attitude in this thread is even less wise. You're not going to get help getting bent out of shape like this, and you're going to wind up with a locked thread if you keep it up.

Read over that site, it will give you some (sane) ideas.

 

[rabidchimp]

That upper tie bar is not heavy at all. Do as others have suggested. Get the unsprung weight down, and maybe remove some interior if you don't care about that. Got a big ass box with subs/amps in the car? Ditch them.
-Aaron

 

[92nsx]

got a big ass box with subs/amps in the car? Ditch them.
-aaron

lol

 

[Koenigturbo]

NO!

 

[SySt]

Back in 2004, at the Texas Supra Nationals, there was a fender bender outside of the Texas World Speedway...

The funny thing is that I remember a post a long time ago about that crash. My only concern was that the support may tie the frame rails together as you have addressed. No one else has a agreed with removing the support. I will leave it in for now. I can always remove it later if I feel I should for some reason.

 

[NashMan]

i cut one of thosu half befor it's layer mealt if remmber right a bitch to cut though

so toyata did reinfroce it

and form the white car posted above this is why i re made a bumper for mr car cause the ic


low impacked don't destroy your car

 

[Keros]

Wear lighter socks.

Cutting 15lbs of metal off the front of a MkIII will be like loading a misquito onto a rhino's back and hoping it'll slow the rhino down when he charges your ass.

The car started out with a decent F/R weight distribution, I think it's 52/48, or something like that?

Let's talk about big picture:

You've gone and put in a 300lb engine in where a ~600lb engine used to be, probably already putting the F/R ratio damn near 50/50 anyway. IIRC (and these numbers are off the top of my head from a document I read a long time ago), the chassis weighs less than 600lbs when totally stripped bare. The front subframe is around 400, the rear 500. The stock turbo driveline (engine ~600, transmission ~150, d/s ~50, and diff ~100) is shy of 1000lbs all totalled up. The rest of the 900lbs of car comes from the interior, electronics, HVAC, suspension components, wheels and tires (my tires are considered light, but still add up to 100lbs), brakes (alot heavier than you think they are).

If you want to save weight get lighter rims and tires, get aluminum brake calipers and rotors with aluminum hats. You'll gain performance and handling without sacrificing anything at all.

Chopping up the lightest major component on the car (the chassis) that is most critical to keeping your ass intact and the car able to deal with the stuff that happens on the road... is sheer madness.

As annoyingrob always says "wieght reduction? Fuck that, It's a MkIII, I'll just make more power to compensate."

If you're worried about weight, get a Miata.

 

[SySt]

Wear lighter socks.

Cutting 15lbs of metal off the front of a MkIII will be like loading a misquito onto a rhino's back and hoping it'll slow the rhino down when he charges your ass.

The car started out with a decent F/R weight distribution, I think it's 52/48, or something like that?

Let's talk about big picture:

You've gone and put in a 300lb engine in where a ~600lb engine used to be, probably already putting the F/R ratio damn near 50/50 anyway. IIRC (and these numbers are off the top of my head from a document I read a long time ago), the chassis weighs less than 600lbs when totally stripped bare. The front subframe is around 400, the rear 500. The stock turbo driveline (engine ~600, transmission ~150, d/s ~50, and diff ~100) is shy of 1000lbs all totalled up. The rest of the 900lbs of car comes from the interior, electronics, HVAC, suspension components, wheels and tires (my tires are considered light, but still add up to 100lbs), brakes (alot heavier than you think they are).

If you want to save weight get lighter rims and tires, get aluminum brake calipers and rotors with aluminum hats. You'll gain performance and handling without sacrificing anything at all.

Chopping up the lightest major component on the car (the chassis) that is most critical to keeping your ass intact and the car able to deal with the stuff that happens on the road... is sheer madness.

As annoyingrob always says "wieght reduction? Fuck that, It's a MkIII, I'll just make more power to compensate."

If you're worried about weight, get a Miata.

Making more power requires more fuel and either more displacement or higher cylinder pressures. So making more power costs more and is generally harder on the engine thus reducing engine life.

I do not think the LS6 weighs 300 pounds. I have always understood that the LS1 fully dressed in F-body or Corvette form is about 430 pounds. I also doubt the 7M fully dressed is 600 pounds. The T56 transmission I have in my car is quite heavy, probably considerably heavier than an R154. Either way, my swap no doubt shed some weight off of my Supra. I also gutted my entire car and removed EVERYTHING I do not feel a need for. All the HVAC stuff, stereo equipment, interior panels aside from the door panels and the dash, every bit of wiring (I rewired my car to my own specification), etc.

The brakes are not heavier than I think. There is no way your stated weights for the subframes is accurate. I can lift and move around each subframe fully dressed with brakes, arms, etc. There is no way I could do that if they were each even just 300 pounds.

I do not want a Miata. I want my Supra, just faster and easier to work on. And by the way, since i've had mis-communication with this, when I say speed I mean the vehicles ability to accelerate, reach peak speeds, go around corners and slow down.

 

[Clip]

weight index has rear rotors, front calipers and equipment. estimated - rotors combined weigh around 55 lbs, calipers, brackets, pads combined will weigh near 48-50 lbs.

its either make more power with the engine and a fully intact frame and replace engine components (i haven't known LSx engines to be considered weak) or make the same amount of power and be wary of twisting and weakening of the frame, not to mention front/side impacts.

 

[Supracentral]

I do not think the LS6 weighs 300 pounds. I have always understood that the LS1 fully dressed in F-body or Corvette form is about 430 pounds. I also doubt the 7M fully dressed is 600 pounds. The T56 transmission I have in my car is quite heavy, probably considerably heavier than an R154.

Toyota||GM|
7M-GTE|440 lbs.|LS-1|390 lbs.
R154|115 lbs.|Borg Warner T56|115-129 lbs.
Totals | 555 lbs. || 505-519 lbs.

Weight for the 7M-GTE includes flywheel,manifolds & turbo.
Weight for the LS-1 includes manifolds, etc but not the flywheel. Likely 15 - 20 lbs for that.

Weights for transmissions do not include fluids,clutch or pressure plate. Differences should be negligible.

There are several Borg Warner T56 variations in GM vehicles. Therefore the weight range. Give me the exact model number and I can give you the exact weight.

There is anywhere from a 36 to 50 lbs weight savings with the LS-1/T56 vs 7M-GTE/R154. Calculate in the flywheel and we're down to about a 16 - 30 lbs. total weight difference.

 

[IJ.]

Distribution is MUCH better with the LS though

 

[Supracentral]

Distribution is MUCH better with the LS though

Correct, weight balance is nearly perfect on that motor. The 7M is very heavy on the right side for obvious reasons...

 

[IJ.]

Yep a little worse here as we're RHD so the car needs the r/s springs wound up another half a turn.

 

[Wiisass]

You need something to connect the frame rails in the front. Something needs to tie them together. The subframe does connect them, but it is isolated from the frame rails because of the bushings. And you also have the spring/shock loads going into the chassis. So you do need something connecting them.

I mean you could lighten up the chassis with a well designed tube frame.

You could replace them with a fabbed piece that will better position/mount whatever rad you're going to use.

Or if you really wanted to, you could cut a bunch of the frame off. You would just have to redesign it and tie everything together and then make a structure to mount the body panels. But with the LSx, you could cut off a decent amount of the front of the chassis. But you would still need to tie the frame rails together and it might be a good idea to tie the shock mounts into the chassis better if you're removing all that material.

And there's a big weight thread on here that I started a while ago. That's where the subframe weights came from. But I think they were quoted wrong. It's on here somewhere and has a lot of info on it. Subframes were heavy, but they included everything. Basically, I disconnected the brake lines, unbolted the shocks and unbolted the subframe. So everything including arms, wheels, brakes, diff, axles, etc was on them.

 

[NashMan]

some one needs to make tube frame sub frames and low front a arms tons of money there


mostly the front less up there the better cause

 

[IJ.]

some one needs to make tube frame sub frames and low front a arms tons of money there


mostly the front less up there the better cause

shhhhh
(I have "plans")

 

[Suprapowaz!(2)]

some one needs to make tube frame sub frames and low front a arms tons of money there


mostly the front less up there the better cause

Would it be affordable to most MKIII owners? Think about your audience.

 

[jdub]

Would it be affordable to most MKIII owners? Think about your audience.

That's a great idea...make it as cheap as possible so it will look good and not do squat. Personally, I could care less if the "masses" can afford a quality fabrication that affords the protection of the stock part in a crash. If you don't have the $$$ to play, get another car.

 

[Poodles]

Include the intercooler and piping and the numbers change quite a bit, especially removing weight in front of the wheels...

But as already mentioned, removing parts of the frame is NOT a good idea. Replacing on the other hand...