Home  
Site Partners: SpotterGuides Veloce Books  
Related Sites: Your Link Here  

Go Back   TenTenths Motorsport Forum > Racing Talk > Racing Technology

Reply
 
Thread Tools Display Modes
Old 7 Nov 2017, 06:34 (Ref:3779174)   #1
Trikes
Rookie
 
Join Date: Jan 2014
Australia
Australia Hobart
Posts: 54
Trikes should be qualifying in the top 10 on the grid
Rear Alignment Questions

Hey Guys Been a while. My Proton Satria GTi has been getting a hammering lately in the Hill Climbs. I know I'm improving as I keep lowering my PB's. This brings to my latest pickle. Recently I had Adjustable Rear Control Arms fitted with an alignment. The car is quite grippy now in the rear.

I recently competed (Hill Climbs) at three Meets in two weekends. The car copped a hammering. At one meeting it was regularly on two wheels thru a series of 5 corner 'S' Bends then at the last meet it was air born twice in the last three runs.

So the rear has 'settled' some 30mm lower and I'm wondering do I just wind it back up 30mm as that's where the alignment was set or will winding it alter the alignment???
Reason for wanting to go back up is the Turn In has changed since lowering itself. I now turn in, lift a little, then have to turn in some more to make the Apex.

Or do I lower the front 15mm and only raise the rear 15mm (I have ground clearance). (This FWD luvs 30mm of Rake). And get another alignment.

Strut type C/O suspension every corner.

Thoughts???
Trikes is offline  
Quote
Old 10 Oct 2018, 21:49 (Ref:3856007)   #2
sambeeb
Rookie
 
Join Date: Aug 2015
Australia
sydney
Posts: 15
sambeeb should be qualifying in the top 10 on the grid
You're in a satria aren't you. I also hillclimb a FWD (with a rear beam though) and have had some pretty solid advice from a pretty solid race engineer lately that has helped transform my car. Based on what I've been told and have subsequently learnt I'd say that the turn in has changed as the rear ride height has dropped because the rear roll centre (and CoG) has moved downward. The flatter roll axis has the car more stable in the rear and therefore less pointy at the nose. If it has toed in at the rear as the ride height has dropped then that would have a huge effect too. I'd move the rear ride height back up to where it was. That'll get the rear roll centre back up (effectively stiffening the rear with geometric roll resistance) and making it livelier in the rear which will help you make the apex. Your car has rear IRS yeah? If the higher ride height gave you some total rear toe out then that would also explain how it wanted to turn better when the ride height was up a bit at the back. Don't drop the front or you'll just mangle your front roll centres if its a mac strut front end.
Mine is a rear twist/torsion beam. I'm running 2 degrees neg camber and 3.2mm rear toe out (total) and the thing just wants to turn now. The advice I've been given and what I have found is that toe out is huge when it comes to how little lock you'll have on at the apex. Provided you are adding camber at the same time (which really helps offset the high speed instability of rear toe out) then the car just comes alive.
sambeeb is offline  
Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Dunlop Optical Alignment gauge instructions Rubinho Racing Technology 2 23 Dec 2005 08:26
Offered: Dunlop wheel alignment tools in UK Jeff Barley Racers Classifieds 3 27 Nov 2005 19:14
Prop shaft alignment listernoble Road Car Forum 1 10 Jan 2005 19:24
ACO 2004 Rear Diffuser vs. Toyota Eagle MkIII GTP Rear Diffuser Dauntless ACO Regulated Series 10 16 Jul 2003 21:21


All times are GMT. The time now is 07:47.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Original Website Copyright © 1998-2003 Craig Antil. All Rights Reserved.
Ten-Tenths Motorsport Forums Copyright © 2004-2021 Royalridge Computing. All Rights Reserved.
Ten-Tenths Motorsport Forums Copyright © 2021-2022 Grant MacDonald. All Rights Reserved.