ride height/alignment specs help - setup listed
Oct 1, 2008, 08:57 AM
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ride height/alignment specs help - setup listed
Long post, I wanted to provide enough info and show you I have done searching etc and wanted some final suggestions. I did look at the wide tire thread as well...
This car has been a project for about a year or now and I am finally ready to set her down next week. As far as suspension goes, here is everything I have done to it...
Suspension:
- Every whiteline bushing available for the car including bump steer, roll-center and precision steer kit
- Whiteline front and rear endlinks
- whiteline front and rear swaybars
- Megan track coilovers (for now, will upgrade later)
- Perrin offset caster bushings in front lower control arms (ALK)
- APR extended lugs all the way around
- 25mm front spacer, going to get a 3 to 5mm spacer for rear, 275's seem like it will hit rear trailing arm during off camber bumps, happens on my buddies Evo with same wheels and tires (read below)
- Other bars and braces which are of no relevance to alignment
Wheel and tire combo:
- The 275-40/17 RT-615's are on 17x9.5 +38 NT-03M for street use and road-race use for novice school days when I cannot run r-comps
- The 285-30/18 Hoosiers are on 18x9.5 +20 rota P45R for autox use only
- The 265-35/18 R888's are on 18x9 +30 Konig Runaways for road-race use only
- The 255-40/17 RT-615's are on 17x8.5 SSR GT-7's for daily use, perhaps (for sale right now)
Body mods:
- Rear fender rolled and pulled as best as possible
- Chargespeed D1 20mm widebody fenders up front. Fender lip was fully removed before painting
- No front fenderliners
I will take to kansas city in a month to get corner balanced and such, but for now I would like to get some sort of alignment coz I am sure its all off from taking suspension off and then installing all the bushings.
A local guy at the Tires Plus will set to whatever alignment I need to. I do have an auto-x in 2 weeks I'd like to shake the car down at and see how she does.
Car will be barely driven on the streets. Mostly trailered as cage doesnt allow to carry a second set to the local auto-x and I am not about to drive around on hoosiers
Here is what I need confirmation on:
1) Rear camber - The 285's worry me in the rear and I was wondering how much camber I need to get to clear the fender. I have seen most guys run about -1.5 or -1.6, can we get more out the rear?
2) front camber - Not too worried. I set front bolts to -2 and camber plates to zero. I can always increase it using the plates. I have seen people run -3.5 sometimes and assume its OK
3) Front and rear Toe - I am not sure whats safe. I don't want tire chew. I see people suggest front to have 1/8th toe out and 0 in rear. Is that safe?
4) Caster - Not a concern, I am guessing? I did give myself some with the perrin bushing, but we'll see if that helps any
5) Ride height - I assume that I can go decently low with the whiteline RCE kit. But I have heard people say to lower rear more than front for braking help - not sure I understand this.
I fully understand that corner balancing will finally set my ride height, but for now any suggestions on how I set it - I read measuring from frame to the ground, but not sure where on the frame. I also read measure from fender to hub center, but this is bad coz evo panels are not quite upto spec and I do have wider front fenders which may differ. Should they be set at the same height front and rear?
Thanks for reading and appreciate any advice!
This car has been a project for about a year or now and I am finally ready to set her down next week. As far as suspension goes, here is everything I have done to it...
Suspension:
- Every whiteline bushing available for the car including bump steer, roll-center and precision steer kit
- Whiteline front and rear endlinks
- whiteline front and rear swaybars
- Megan track coilovers (for now, will upgrade later)
- Perrin offset caster bushings in front lower control arms (ALK)
- APR extended lugs all the way around
- 25mm front spacer, going to get a 3 to 5mm spacer for rear, 275's seem like it will hit rear trailing arm during off camber bumps, happens on my buddies Evo with same wheels and tires (read below)
- Other bars and braces which are of no relevance to alignment
Wheel and tire combo:
- The 275-40/17 RT-615's are on 17x9.5 +38 NT-03M for street use and road-race use for novice school days when I cannot run r-comps
- The 285-30/18 Hoosiers are on 18x9.5 +20 rota P45R for autox use only
- The 265-35/18 R888's are on 18x9 +30 Konig Runaways for road-race use only
- The 255-40/17 RT-615's are on 17x8.5 SSR GT-7's for daily use, perhaps (for sale right now)
Body mods:
- Rear fender rolled and pulled as best as possible
- Chargespeed D1 20mm widebody fenders up front. Fender lip was fully removed before painting
- No front fenderliners
I will take to kansas city in a month to get corner balanced and such, but for now I would like to get some sort of alignment coz I am sure its all off from taking suspension off and then installing all the bushings.
A local guy at the Tires Plus will set to whatever alignment I need to. I do have an auto-x in 2 weeks I'd like to shake the car down at and see how she does.
Car will be barely driven on the streets. Mostly trailered as cage doesnt allow to carry a second set to the local auto-x and I am not about to drive around on hoosiers
Here is what I need confirmation on:
1) Rear camber - The 285's worry me in the rear and I was wondering how much camber I need to get to clear the fender. I have seen most guys run about -1.5 or -1.6, can we get more out the rear?
2) front camber - Not too worried. I set front bolts to -2 and camber plates to zero. I can always increase it using the plates. I have seen people run -3.5 sometimes and assume its OK
3) Front and rear Toe - I am not sure whats safe. I don't want tire chew. I see people suggest front to have 1/8th toe out and 0 in rear. Is that safe?
4) Caster - Not a concern, I am guessing? I did give myself some with the perrin bushing, but we'll see if that helps any
5) Ride height - I assume that I can go decently low with the whiteline RCE kit. But I have heard people say to lower rear more than front for braking help - not sure I understand this.
I fully understand that corner balancing will finally set my ride height, but for now any suggestions on how I set it - I read measuring from frame to the ground, but not sure where on the frame. I also read measure from fender to hub center, but this is bad coz evo panels are not quite upto spec and I do have wider front fenders which may differ. Should they be set at the same height front and rear?
Thanks for reading and appreciate any advice!
Oct 1, 2008, 11:05 AM
#2
People like you make others want to help, very detailed post with what's on the car and what you are trying to acheive; newbies take notes
.
Alignment specs(optimum) are something that should be different in every car because we don't have the same spring rates, sway bars, tire size and compound.
Another important thing to remember is that the agressive alignment needed to be competitive at autocross would be a handfull at the road course and suicidal in the streets so you need a dedicated specs for each.
With that said, people who have set up their car for the same tracking purposes, can give you ballpark specs that you can use a starting point but will need to be fine tuned for your car and driving preferences(neutral vs loose).
What I can tell you from my experiences since you are heading to an auto-x:
1) Rear camber you can get more than 1.5/1.6 neg camber and can probrably use more than that. I usually run around 2.5 on asphalt and around 3 on grippy concrete. Some might argue that it's too much but temp spread and shots of the car when loaded suggest that the camber loss on 16k springs needs it.
You can see from this pic for example that the rear wheel with all that camber and 16k springs is going positive.
2) Front camber Start around 3.2 and increase as needed.
I run 3.5 to 4.0 neg front camber with 12k springs and upgraded sway bar and get almost even temp sread with outside temps averaging about 10 degrees above the middle.
3) Front and rear Toe I would suggest starting wit 0 rear toe and about a 1/16 -1/8 toe out front.
4) Caster As much positive as you can if you have the luxury of adjustability.
5) Ride height That's a sensitive part of setting your car as you can easily screw things up. You would have to at least calculate you center of gravity and Roll Center to get this perfect. As a starting point for the evo, I go as low as I can in the rear and rake the front about an inch higher than the rear. A couple pointers is that you want your lower control arms to be at most, parallel to the ground and your roll center above ground and as close as possible to the CG.
That's the rake(front higher than rear) that you should be aiming for. Mine looks like the front is more than an inch higher than the back because the front fenders are heavily cut.
That should give a starting point but corner balancing and testing a the track is what will optimize your set up.
.Alignment specs(optimum) are something that should be different in every car because we don't have the same spring rates, sway bars, tire size and compound.
Another important thing to remember is that the agressive alignment needed to be competitive at autocross would be a handfull at the road course and suicidal in the streets so you need a dedicated specs for each.
With that said, people who have set up their car for the same tracking purposes, can give you ballpark specs that you can use a starting point but will need to be fine tuned for your car and driving preferences(neutral vs loose).
What I can tell you from my experiences since you are heading to an auto-x:
1) Rear camber you can get more than 1.5/1.6 neg camber and can probrably use more than that. I usually run around 2.5 on asphalt and around 3 on grippy concrete. Some might argue that it's too much but temp spread and shots of the car when loaded suggest that the camber loss on 16k springs needs it.
You can see from this pic for example that the rear wheel with all that camber and 16k springs is going positive.2) Front camber Start around 3.2 and increase as needed.
I run 3.5 to 4.0 neg front camber with 12k springs and upgraded sway bar and get almost even temp sread with outside temps averaging about 10 degrees above the middle.
3) Front and rear Toe I would suggest starting wit 0 rear toe and about a 1/16 -1/8 toe out front.
4) Caster As much positive as you can if you have the luxury of adjustability.
5) Ride height That's a sensitive part of setting your car as you can easily screw things up. You would have to at least calculate you center of gravity and Roll Center to get this perfect. As a starting point for the evo, I go as low as I can in the rear and rake the front about an inch higher than the rear. A couple pointers is that you want your lower control arms to be at most, parallel to the ground and your roll center above ground and as close as possible to the CG.
That's the rake(front higher than rear) that you should be aiming for. Mine looks like the front is more than an inch higher than the back because the front fenders are heavily cut.
That should give a starting point but corner balancing and testing a the track is what will optimize your set up.
Oct 1, 2008, 12:16 PM
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madmax199 - thanks for the compliment, I truly appreciate it. I know people make posts for alignment specs over and over, but I researched it first and wanted some opinions. I don't want to think I am just some idiot doing it.
But, I have surfed your posts in the past and we talked once about your tire setup via PM. I am too chicken to cut my rear fender like you
I appreciate
OK, have some follow-up questions:
Rear camber - Wow, I didnt know you could get that much out of the rear!!!! Are you using stock bolts? Do you have adjustable plates up top?
Front camber - did you do -2 with the bolt out and rest with plates or do you have bolts like the ingalls ones up front?
Ride height - I will do as you suggested, sir? Do I measure at the pinch welds on the frame? Is there a science to it?
Caster - It is not adjustable in front with the Perrin. Its just offset, not sure by how much either. I was one of the 1st to get it and I had to grind the control arm etc to make it work. I wish someone had made just a bushing for that sucka, but it is a pillow ball bushing like stock...
My megans are 12K/10K - Also, my cars weight has been reduced by a bit - I am hoping for 2900 without driver which is lofty. I can list all my mods, but I don't want to come off like a brag...
I will post a few pics of my car which suggests the work done to it... I will do an official build thread sometime when I am all done
But, I have surfed your posts in the past and we talked once about your tire setup via PM. I am too chicken to cut my rear fender like you
I appreciateOK, have some follow-up questions:
Rear camber - Wow, I didnt know you could get that much out of the rear!!!! Are you using stock bolts? Do you have adjustable plates up top?
Front camber - did you do -2 with the bolt out and rest with plates or do you have bolts like the ingalls ones up front?
Ride height - I will do as you suggested, sir? Do I measure at the pinch welds on the frame? Is there a science to it?
Caster - It is not adjustable in front with the Perrin. Its just offset, not sure by how much either. I was one of the 1st to get it and I had to grind the control arm etc to make it work. I wish someone had made just a bushing for that sucka, but it is a pillow ball bushing like stock...
My megans are 12K/10K - Also, my cars weight has been reduced by a bit - I am hoping for 2900 without driver which is lofty. I can list all my mods, but I don't want to come off like a brag...
I will post a few pics of my car which suggests the work done to it... I will do an official build thread sometime when I am all done
Last edited by EvoIXMR; Oct 1, 2008 at 12:34 PM.
Oct 1, 2008, 12:27 PM
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PS - I am not VTAing. So, don't start yelling at me, people... . Car isnt fully done yet, I have a few more things to tidy up. My tcase came back from TRE this week and final stuff can be done this week
. Car isnt fully done yet, I have a few more things to tidy up. My tcase came back from TRE this week and final stuff can be done this week
Oct 1, 2008, 02:11 PM
#6
Nice build !!!
Couple of things:
Your coilover's spring rates are in the wrong order, the evo's motion ratio dictate stiffer rear springs like in the stock set up. I would suggest a) that you flip your springs(front to rear) altough it'll be on the soft side for what you are doing; or b) if you entend to keep the megan coilovers for long, use the rear 12ks in the front and order a set of 14k spring for the rear(don't worry I ran them in my evo like that for a full season in the past)
You can get some decent static negative camber out of the rear without camber plates using the stock adjustments.
I used the stock bolts, in the front, at their max setting and used the top plates to dial the rest.
Ride height is, like I mentioned earlier easy to screw up. I see lots of evos dropped way to much because they assume that a roll center correction kit allows the car to become a low rider. Again do not go lower than what the suspension geometry allows, improved or not (remember lower control arms parallel to ground but not lower).
Couple of things:
Your coilover's spring rates are in the wrong order, the evo's motion ratio dictate stiffer rear springs like in the stock set up. I would suggest a) that you flip your springs(front to rear) altough it'll be on the soft side for what you are doing; or b) if you entend to keep the megan coilovers for long, use the rear 12ks in the front and order a set of 14k spring for the rear(don't worry I ran them in my evo like that for a full season in the past)
You can get some decent static negative camber out of the rear without camber plates using the stock adjustments.
I used the stock bolts, in the front, at their max setting and used the top plates to dial the rest.
Ride height is, like I mentioned earlier easy to screw up. I see lots of evos dropped way to much because they assume that a roll center correction kit allows the car to become a low rider. Again do not go lower than what the suspension geometry allows, improved or not (remember lower control arms parallel to ground but not lower).
Oct 1, 2008, 02:31 PM
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I wasn't sure if the springs were actually too much for a gutted out car like mine, sir! If I have taken 300 lbs off it, I am not sure if that sorta makes up for the lack of spring rate? Hope I am making sense. I am sure megans sell 14K.
So, I am clear - the spring is not to help rear rotation or create oversteer, correct? Coz the rear is much lighter than the front due to iron block, subframe, tcase etc
Now, I do have the ralliart LSD in the car along with full t-case shot-peening as well as the TRE rear differential upgrade with the 1 way addition. I use Mr. Ripple exclusively for my work and highly recommend him.
Awesome advice, thanks a lot. I will check with Zues the Megan man on 14K spring pricing. I appreciate it. I will update this thread perhaps to help newbs like me and that way its archived.
Take care and thanks again for all the time and effort you are putting into this!
So, I am clear - the spring is not to help rear rotation or create oversteer, correct? Coz the rear is much lighter than the front due to iron block, subframe, tcase etc
Now, I do have the ralliart LSD in the car along with full t-case shot-peening as well as the TRE rear differential upgrade with the 1 way addition. I use Mr. Ripple exclusively for my work and highly recommend him.
Awesome advice, thanks a lot. I will check with Zues the Megan man on 14K spring pricing. I appreciate it. I will update this thread perhaps to help newbs like me and that way its archived.
Take care and thanks again for all the time and effort you are putting into this!
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Oct 1, 2008, 04:12 PM
#8
I wasn't sure if the springs were actually too much for a gutted out car like mine, sir! If I have taken 300 lbs off it, I am not sure if that sorta makes up for the lack of spring rate? Hope I am making sense. I am sure megans sell 14K.
So, I am clear - the spring is not to help rear rotation or create oversteer, correct? Coz the rear is much lighter than the front due to iron block, subframe, tcase etc
Now, I do have the ralliart LSD in the car along with full t-case shot-peening as well as the TRE rear differential upgrade with the 1 way addition. I use Mr. Ripple exclusively for my work and highly recommend him.
Awesome advice, thanks a lot. I will check with Zues the Megan man on 14K spring pricing. I appreciate it. I will update this thread perhaps to help newbs like me and that way its archived.
Take care and thanks again for all the time and effort you are putting into this!
So, I am clear - the spring is not to help rear rotation or create oversteer, correct? Coz the rear is much lighter than the front due to iron block, subframe, tcase etc
Now, I do have the ralliart LSD in the car along with full t-case shot-peening as well as the TRE rear differential upgrade with the 1 way addition. I use Mr. Ripple exclusively for my work and highly recommend him.
Awesome advice, thanks a lot. I will check with Zues the Megan man on 14K spring pricing. I appreciate it. I will update this thread perhaps to help newbs like me and that way its archived.
Take care and thanks again for all the time and effort you are putting into this!
The choice of spring rates is not to help oversteer or create rotation, it is mainly to keep roll in check and limit the associated camber loss and inside rear lift. With softer springs the car would roll a lot, creating understeer, lifting the inside rear and delaying your ability to be back on the gas early and hard. This old pic is my car with 10k/12k front rear, not the fast way around the track since it's ideal to have all 4 wheel planted on the ground.
Oct 1, 2008, 08:58 PM
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thanks, Fred. Appreciate it man. I will get some good pics when fully done. TC case went back in, so did subframe, etc. just filling fluids now. I should be able to start her up by the weekend if I wasnt going to AMS swap meet and MOD... 
Oct 2, 2008, 09:02 PM
#14
Wow, didn't know you guys were successfully using that much spring. Very interesting indeed. Pics are very reveling madmax199.
Looks like you are definitely being guided in the right direction EvoIXMR...
Looks like you are definitely being guided in the right direction EvoIXMR...
Last edited by Zeus; Oct 2, 2008 at 09:05 PM.
Oct 2, 2008, 09:23 PM
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great thread.
my search has ended for a to-the-point suspension thread that would reflect the modifications I will be adding on my EVO once I can get out of school.
my search has ended for a to-the-point suspension thread that would reflect the modifications I will be adding on my EVO once I can get out of school.