1992 fd3s chassis stiffening/refresh

kariayam · 06-25-2011, 05:09 AM

Hi all.

I own a FD3S and the chassis seemes to be too old now (year 1992 and 19 years old of age..). I am thinking to refresh the aging chassis and reduce as much flex. So I am planning to do spot welds on the chassis for refreshing the old chassis.

My target of spot welds :

1- just to have 'new' chassis feel and solid handling on normal road since this is on-the-road car.

2- 70% will be driven agrresively on normal uneven poor quality roads and 30% track day.

3-to eliminate body flex. Can be easily seen when i jack up the car at one corner and creaking sound is everywhere..

I dont know if i have to weld the whole body or only at some critical point of the body to get the purpose as i mentioned above. I also dont know where is the critical part of the body to do the spot welds. As I know, the main area of spot weld are:

1)door jamb area
2)front windshield area
3)Rear hatchback opening and spare tyre well
4)Firewall
5)Engine bay,
6)suspension tower Front and rear..

How about:
7)transmisson tunnel area?
8)Floor area?

Really need opinion from you guys on the sufficient weld areas to meet my target/purposes as stated above.

Some of my friends suggested spot weld the whole unibody. But I am afraid it will be too stiff and hard for bumpy roads and sacrifice my traction or handling and crack the body over days.

( As i know, the chassis still needs some very little flex for good traction and handling). Please correct me if i am wrong...because i never involved in a professional motorsport, I just read in the internet..

Signal 2 · 06-28-2011, 03:45 PM

*The creaking sounds you hear may just be suspension, not chassis. Jack the car up again and exam the door, hood and hatch gaps. If they don't change significantly, stiffening is probably not needed.
*Remove and inspect your Power Plant Frame (PPF) for any signs of fatigue or cracking, especially around the mounting points. IMO, that would be the place to begin reinforcment.

I don't track my car. Only the occasional autocross. I do know there are some commercially produced bracing kits available. But I also know guys that track their cars frequently and don't seem to need them.

yzf-r1 · 07-05-2011, 10:48 PM

First things first: check the powerplant frame (as already mentioned) and replace all the bushings with polyurethane

dvo · 07-07-2011, 07:35 PM

Fender Brace? Motoiq did a pretty good writeup on these and I've been thinking about them ever since.

http://www.motoiq.com/magazine_artic...ke-system.aspx

Nagisa also makes it for the FD

Signal 2 · 07-10-2011, 10:03 AM

I'm usually a little (alot) skeptical of most of those magazines. The articles all just seem like feature length advertisement with a "how-to" thrown in. Maybe they're out there, but I've never seen a "review" of a part that was negative.

I think the OP is trying to fix something that isn't broken.

Doc-1 · 09-07-2011, 10:40 PM

The fender brace maybe the best brace you can add. I put them on and the difference was spectacular.

Signal 2 · 09-09-2011, 01:29 PM

^Do you track your car? Autocross?

06-25-2011, 05:09 AM	#1
kariayam The Newbie Join Date: Sep 2010 Location: malaysia Posts: 5 Rep Power: 0	1992 fd3s chassis stiffening/refresh Hi all. I own a FD3S and the chassis seemes to be too old now (year 1992 and 19 years old of age..). I am thinking to refresh the aging chassis and reduce as much flex. So I am planning to do spot welds on the chassis for refreshing the old chassis. My target of spot welds : 1- just to have 'new' chassis feel and solid handling on normal road since this is on-the-road car. 2- 70% will be driven agrresively on normal uneven poor quality roads and 30% track day. 3-to eliminate body flex. Can be easily seen when i jack up the car at one corner and creaking sound is everywhere.. I dont know if i have to weld the whole body or only at some critical point of the body to get the purpose as i mentioned above. I also dont know where is the critical part of the body to do the spot welds. As I know, the main area of spot weld are: 1)door jamb area 2)front windshield area 3)Rear hatchback opening and spare tyre well 4)Firewall 5)Engine bay, 6)suspension tower Front and rear.. How about: 7)transmisson tunnel area? 8)Floor area? Really need opinion from you guys on the sufficient weld areas to meet my target/purposes as stated above. Some of my friends suggested spot weld the whole unibody. But I am afraid it will be too stiff and hard for bumpy roads and sacrifice my traction or handling and crack the body over days. ( As i know, the chassis still needs some very little flex for good traction and handling). Please correct me if i am wrong...because i never involved in a professional motorsport, I just read in the internet..

06-28-2011, 03:45 PM	#2
Signal 2 Viable Fossil Join Date: Mar 2008 Location: Mid-West Posts: 199 Rep Power: 18	The creaking sounds you hear may just be suspension, not chassis. Jack the car up again and exam the door, hood and hatch gaps. If they don't change significantly, stiffening is probably not needed. Remove and inspect your Power Plant Frame (PPF) for any signs of fatigue or cracking, especially around the mounting points. IMO, that would be the place to begin reinforcment. I don't track my car. Only the occasional autocross. I do know there are some commercially produced bracing kits available. But I also know guys that track their cars frequently and don't seem to need them. __________________ Jim VR R1 FD Last edited by Signal 2; 06-28-2011 at 03:59 PM.

07-10-2011, 10:03 AM	#5
Signal 2 Viable Fossil Join Date: Mar 2008 Location: Mid-West Posts: 199 Rep Power: 18	I'm usually a little (alot) skeptical of most of those magazines. The articles all just seem like feature length advertisement with a "how-to" thrown in. Maybe they're out there, but I've never seen a "review" of a part that was negative. I think the OP is trying to fix something that isn't broken. __________________ Jim VR R1 FD

09-09-2011, 01:29 PM	#7
Signal 2 Viable Fossil Join Date: Mar 2008 Location: Mid-West Posts: 199 Rep Power: 18	^Do you track your car? Autocross? __________________ Jim VR R1 FD

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07-05-2011, 10:48 PM	#3
yzf-r1 Banned Join Date: Mar 2010 Posts: 67 Rep Power: 0	First things first: check the powerplant frame (as already mentioned) and replace all the bushings with polyurethane

07-07-2011, 07:35 PM	#4
dvo The Newbie Join Date: Mar 2011 Location: SoCal 310 Posts: 28 Rep Power: 0	Fender Brace? Motoiq did a pretty good writeup on these and I've been thinking about them ever since. http://www.motoiq.com/magazine_artic...ke-system.aspx Nagisa also makes it for the FD

09-07-2011, 10:40 PM	#6
Doc-1 Rotary Fanatic Join Date: Feb 2008 Location: Madison Alabama Posts: 115 Rep Power: 18	The fender brace maybe the best brace you can add. I put them on and the difference was spectacular.