Chassis and Suspension Required Reading.

treekiller · 03-18-2008, 09:10 PM

I'm attempting to compile the brain trust of our community and post it in the following post over in our sister forum, if any of our more experienced drivers/tuners care to add to or handle one of the topics I'd appreciate the help as writing it all by myself while I can do it all, it will take me a month. (I bit off more then I can chew)

http://www.tamparacing.com/forums/ch...ml#post5224950

if there is something you see needs addressing or you want to add one of the topics I'll welcome the content.

I felt it was paramount to identify the truth from the common misconceptions that exist over there.

PM me your entry and I'll post it. eventually I plan on making the ultimate suspension FAQ out of the data.

**Loren** · 03-18-2008, 10:02 PM

If my Triumph had a double-wishbone setup to go with the transverse leaf, it wouldn't have the bad habits that it does. Your diagram is more akin to a Corvette suspension than a Triumph suspension. If you're going to talk about the awfulness of the Triumph transverse leaf (and VW Bug), you should use the proper diagram to represent it. (hint: there is no upper control arm, the ends of the spring are the only thing used to locate the top of the hub, hence mondo positive camber on droop) The diagram you have is not of a Triumph suspension, and should behave just like a double A-arm suspension with coil springs.

Edit: Come to think of it, there's no lower control arm, either... it's a swing-axle suspension. The axle acts as a lower control arm, the spring acts as the upper control arm. It really is an awful design... but it's very lightweight, very compact, and very cheap to produce. All were good things for Triumph when they initially used it in the Herald (which was a commuter car, not a sports car).

treekiller · 03-19-2008, 12:25 AM

okay Loren now it's my turn. tell me what YOU want that section to say and I'll fix it. I did my best from my knowledge and that is limited. please give me the correct content and I'll add it. if you have a photo or diagram I'd appreciate it. I'm trying to cover all bases. and I'm not a brittish car guy so forgive me I can add a 10th design although I thought it useless for the intended audience. since I explained why the trimpuh way was wrong. and why you shouldn't do that.

Spin Out · 03-19-2008, 09:20 AM

Nice post, thanks.

**Loren** · 03-19-2008, 09:57 AM

If I only had time.

Basically, I think what you did was apply the term "transverse spring" (which the Spitfire has, but so does the Corvette) to mean "swing axle" (which the Spitfire and early Beetle have, but the Corvette does not).

Do a little research on "Transverse Spring" applications such as the Corvette, which use double-wishbone, such as your diagram. Then do a little research on the awfulness that is "Swing Axle" suspension.

Swing axle - Wikipedia, the free encyclopedia

Corvette leaf spring - Wikipedia, the free encyclopedia

I can't find it right now, but somewhere out there is a web page with good diagrams that explains how the modern Corvette suspension uses its composite springs (front and rear!) to act as anti-roll bars. It has to do with additional fulcrum points that cause the spring to bend in the form of an S, which changes the spring rate on one side vs the other (just like a swaybar would). It's pretty slick, but makes you wonder how the hell the springs keep from breaking.

03-18-2008, 09:10 PM	#1 (permalink)
treekiller legend behind the cowl Car: QR25DE B15 My TRGarage : 63642343	Chassis and Suspension Required Reading. I'm attempting to compile the brain trust of our community and post it in the following post over in our sister forum, if any of our more experienced drivers/tuners care to add to or handle one of the topics I'd appreciate the help as writing it all by myself while I can do it all, it will take me a month. (I bit off more then I can chew) http://www.tamparacing.com/forums/ch...ml#post5224950 if there is something you see needs addressing or you want to add one of the topics I'll welcome the content. I felt it was paramount to identify the truth from the common misconceptions that exist over there. PM me your entry and I'll post it. eventually I plan on making the ultimate suspension FAQ out of the data.

03-18-2008, 10:02 PM	#2 (permalink)
Loren Moderator Car: 2007 Toyota Yaris LB . . . 1976 Triumph Spitfire My TRGarage Safety Harbor : 22047924	If my Triumph had a double-wishbone setup to go with the transverse leaf, it wouldn't have the bad habits that it does. Your diagram is more akin to a Corvette suspension than a Triumph suspension. If you're going to talk about the awfulness of the Triumph transverse leaf (and VW Bug), you should use the proper diagram to represent it. (hint: there is no upper control arm, the ends of the spring are the only thing used to locate the top of the hub, hence mondo positive camber on droop) The diagram you have is not of a Triumph suspension, and should behave just like a double A-arm suspension with coil springs. Edit: Come to think of it, there's no lower control arm, either... it's a swing-axle suspension. The axle acts as a lower control arm, the spring acts as the upper control arm. It really is an awful design... but it's very lightweight, very compact, and very cheap to produce. All were good things for Triumph when they initially used it in the Herald (which was a commuter car, not a sports car). Last edited by Loren : 03-18-2008 at 10:10 PM. Reason: more to say

03-19-2008, 12:25 AM	#3 (permalink)
treekiller legend behind the cowl Car: QR25DE B15 My TRGarage : 63642343	okay Loren now it's my turn. tell me what YOU want that section to say and I'll fix it. I did my best from my knowledge and that is limited. please give me the correct content and I'll add it. if you have a photo or diagram I'd appreciate it. I'm trying to cover all bases. and I'm not a brittish car guy so forgive me I can add a 10th design although I thought it useless for the intended audience. since I explained why the trimpuh way was wrong. and why you shouldn't do that. Last edited by treekiller : 03-19-2008 at 12:34 AM.

03-19-2008, 09:20 AM	#4 (permalink)
Spin Out Registered User Car: '05 MX-5 / '81 Delorean / GRM$2007 Fiero GT My TRGarage Brandon : 184	Nice post, thanks.

03-19-2008, 09:57 AM	#5 (permalink)
Loren Moderator Car: 2007 Toyota Yaris LB . . . 1976 Triumph Spitfire My TRGarage Safety Harbor : 22047924	If I only had time. Basically, I think what you did was apply the term "transverse spring" (which the Spitfire has, but so does the Corvette) to mean "swing axle" (which the Spitfire and early Beetle have, but the Corvette does not). Do a little research on "Transverse Spring" applications such as the Corvette, which use double-wishbone, such as your diagram. Then do a little research on the awfulness that is "Swing Axle" suspension. Swing axle - Wikipedia, the free encyclopedia Corvette leaf spring - Wikipedia, the free encyclopedia I can't find it right now, but somewhere out there is a web page with good diagrams that explains how the modern Corvette suspension uses its composite springs (front and rear!) to act as anti-roll bars. It has to do with additional fulcrum points that cause the spring to bend in the form of an S, which changes the spring rate on one side vs the other (just like a swaybar would). It's pretty slick, but makes you wonder how the hell the springs keep from breaking.