Spic Racer GT40R
Thread Starter
Joined: Mar 2002
Posts: 1,618
Likes: 502
From: The Elysian Fields (Texas)
Corner weights
Peter: I've got a little time this weekend if you'd like to come over and we can see if we could redo your canister mounts. Call or text.
Took the CYM fuel-to-noise converter to Piper Motorsport for suspension tweaking (thanks Mitch, Robbie and the Piper crew). Very happy with the corner weights:
..............TOTAL: 2748.................
LR: 770............................RR: 677
......LF/RR: 49.3%...RF/LR: 50.6%
Was talking with Crispy and he made the insightful observation that rearward weight shift is a natural result of "race" configured FDs. Though I concur with him in suspecting that (within a marginal range) this a good thing for performance optimization, I'd like to hear other perspectives... what'll ya'll think?
So I guess I'm down to bribing and/or cajoling the fancy-pants tuner(Shane T) to find some time for little old me and my piece of rotary sunshine!
Took the CYM fuel-to-noise converter to Piper Motorsport for suspension tweaking (thanks Mitch, Robbie and the Piper crew). Very happy with the corner weights:
- 210 lbs - driver seat weight
- 120 lbs - full fuel tank
- 25.25" - ride height baseline
..............TOTAL: 2748.................
LR: 770............................RR: 677
......LF/RR: 49.3%...RF/LR: 50.6%
Was talking with Crispy and he made the insightful observation that rearward weight shift is a natural result of "race" configured FDs. Though I concur with him in suspecting that (within a marginal range) this a good thing for performance optimization, I'd like to hear other perspectives... what'll ya'll think?
So I guess I'm down to bribing and/or cajoling the fancy-pants tuner(Shane T) to find some time for little old me and my piece of rotary sunshine!
Peter: I've got a little time this weekend if you'd like to come over and we can see if we could redo your canister mounts. Call or text.
Took the CYM fuel-to-noise converter to Piper Motorsport for suspension tweaking (thanks Mitch, Robbie and the Piper crew). Very happy with the corner weights:
..............TOTAL: 2748.................
LR: 770............................RR: 677
......LF/RR: 49.3%...RF/LR: 50.6%
Was talking with Crispy and he made the insightful observation that rearward weight shift is a natural result of "race" configured FDs. Though I concur with him in suspecting that (within a marginal range) this a good thing for performance optimization, I'd like to hear other perspectives... what'll ya'll think?
Took the CYM fuel-to-noise converter to Piper Motorsport for suspension tweaking (thanks Mitch, Robbie and the Piper crew). Very happy with the corner weights:
- 210 lbs - driver seat weight
- 120 lbs - full fuel tank
- 25.25" - ride height baseline
..............TOTAL: 2748.................
LR: 770............................RR: 677
......LF/RR: 49.3%...RF/LR: 50.6%
Was talking with Crispy and he made the insightful observation that rearward weight shift is a natural result of "race" configured FDs. Though I concur with him in suspecting that (within a marginal range) this a good thing for performance optimization, I'd like to hear other perspectives... what'll ya'll think?
It is heaviest at the Driver side Rear b/c that is where driver's weight is carried.
https://www.rx7club.com/showpost.php...&postcount=678
Carlos, what is your goal for the car? Is this the ultimate fun track day car or are you looking to TT/W2W race with it? If you are looking to TT/Race and based on what class you want to fit your car in, you might be able to add ballast to the car to REALLY get your corner weights even as well as lower your center of gravity in the process. I'm in the process of doing this currently my car. My car has a long way to go on the suspension/chassis though. I'm currently 50/50 cross and 49.6F/50.4R. Basically I needed to add some weight to my car to compensate my power to weight ratio for the extra rubber I put under the car. I'm looking for a 25/25/25/25 balance. My car isn't the fastest car in the world, but it's plenty fast enough for me(and my class is capable of running sub 2's at VIR). Plus it's overbuilt and under worked to hopefully keep it reliable on track for many seasons to come. I've had a couple of friends do the 25/25/25/25 balance by adding ballast and have been extremely happy with the results.
Thread Starter
Joined: Mar 2002
Posts: 1,618
Likes: 502
From: The Elysian Fields (Texas)
Big A: Oh, sure, now you tell me! 
Guess that what I get for not diligently searching the Forum.
I gotta admit I would have been very interested to see the numbers with the car set even. For that matter, think I'll measure the ride height currently to see how much deviation it ended up with.
In the end, I suspect the best thing I can do is to get on diet!
Brent: More of the former without hopefully precluding the option of growing into the latter. The determinant will be the quality and quantity of seat time.
Maybbbee... see above.
Insightful advice Brent. I've already been thinking of marginal steps to help shift weight L -> R and more specifically LR -> RF. Though ballast is an option, I'll have plenty of time to think of other alternative (e.g. future fuel cell location).
Testify... cause I'm right there with you!! Especially since I'm deep into the "Conscious Incompetent" stage in my track-work.
Guess that what I get for not diligently searching the Forum. I gotta admit I would have been very interested to see the numbers with the car set even. For that matter, think I'll measure the ride height currently to see how much deviation it ended up with.
In the end, I suspect the best thing I can do is to get on diet!
Maybbbee... see above.
Insightful advice Brent. I've already been thinking of marginal steps to help shift weight L -> R and more specifically LR -> RF. Though ballast is an option, I'll have plenty of time to think of other alternative (e.g. future fuel cell location).
Testify... cause I'm right there with you!! Especially since I'm deep into the "Conscious Incompetent" stage in my track-work.
What worked on my car with a different setup might not have worked on yours. Either way, now you KNOW how your car sits.
Oddly enough, the FD's chassis is much more weight balanced than my Spec Miata. The SM is goofy and just about impossible to get even.
I have another race at Thunderhill this weekend! Can't wait. It is going to be a blast ripping up the track in the SM and then watching fingerlock in his yellow FD tear it up in ITE and beat up on some of the crappy BMWs and Mustangs and Porsches and Vipers.
Got motivation yet?
Thread Starter
Joined: Mar 2002
Posts: 1,618
Likes: 502
From: The Elysian Fields (Texas)
Idle hands are the devil's workshop, so to stay out of trouble I've bought this beauty. Thinkin I'll start with set rails and work my way into mechanical virtue from there... 
Last edited by Gen2n3; Dec 31, 2020 at 06:15 PM.
Thread Starter
Joined: Mar 2002
Posts: 1,618
Likes: 502
From: The Elysian Fields (Texas)
As the old saying goes, be careful what you ask for or you might get it. So when I posted above "Idle hands are the devil's workshop," I set myself up. Been overloaded trying to get my thesis Project done early since getting to school, so I expect to have the car on the back burner for at least another month. Heck, I haven't even been on this forum since later September. Anyways, hoping the other adage about "absence makes the heart grow fonder" is also true.. hopefully more then! ;-)
Yowza!!! Now that I think about it, I'm starting to feel like a Jim LaBreck with this seemingly perpetual project! :-(
Yowza!!! Now that I think about it, I'm starting to feel like a Jim LaBreck with this seemingly perpetual project! :-(
Thread Starter
Joined: Mar 2002
Posts: 1,618
Likes: 502
From: The Elysian Fields (Texas)
Big A: Not yet but I did finish my Project/Thesis about two weeks ago. Asides from the distrations/cost of buying a house in our next duty station (CT), I should be able to get back in the garage and re-start pushing the rotary rock up the hill again. Ahhhh... foolish optimism spring eternal in me!
MB: Going to play with fabricating a couple TI parts. Looking for a local water jet cutter to make some seat rails first. The sheet is a little think from some of my other ideas, but I'll be looking to replace some of the brackets on the car as I learn optimal uses for the material. Needless to say, more to follow...
MB: Going to play with fabricating a couple TI parts. Looking for a local water jet cutter to make some seat rails first. The sheet is a little think from some of my other ideas, but I'll be looking to replace some of the brackets on the car as I learn optimal uses for the material. Needless to say, more to follow...
