Overall Suspension Question (mostly auto-x)
I recently purchased a high-mileage, but realitively babied Evo IX MR and want to auto-x / DD the vehicle. I had a IX MR previously (2010), but a Subaru driver felt I didn't need it anymore and decided to t-bone it with my then-pregnant wife inside. Everything turned out ok, and now I have a new Evo to mod.
What I would like from the vehilce is a good auto-x car and DD. The mods already on the car are: - KYB Shocks (the original MR Bilsteins were sent back for OEM revalving by the original owner and are sitting in a box in my garage) - Tubular manifold (will replace with a ported stocker) - Megan O2 housing - Upgraded Intercooler - Pro-tune focused on fuel economy - That's it... So, since it is pretty much a blank slate, here is the direction (and order) I am leaning: - Swift Spec-R MR Springs (should I send the Bilsteins back to have the revalved for the spring, or is OEM fine and I can save my $300+ shipping?) - Whiteline Front / Rear Swaybars - Roll-center kit - Stainless brake lines - Upgraded Diff (TRE probably because they offer core replacement) I am deploying in about a month, so I will have some time to save money and shop for good deals; I will likely pick up the rear diff toward the end of the deployment. I did a lot of the work on my IX, so I know how to do a good chunk of the installations (other than cams, head work, etc...). What else should I add, suspension / drivetrain wise to improve the vehicle? I know driver mod is the best, but until I can work on that I would like to do more to the vehicle. What I don't want is crazy harsh bushings that make driving the Evo every day a chore. Not related to the suspension question, but instead of making a new thread: How about power? What is a 'good level' for auto-x? Where should I stop, mod wise, to make the best power / handling trade-off? I don't plan to push the power envelope to the bleeding edge, regardless. I was thinking full bolt-ons then stop. Thank you very much for your time and consideration. |
That's not a bad start by any means. Check with your classing rules about the roll center kit....it's a great piece if it's allowed. Other than that, get as many bushings as you can (rear bumpsteer kit, rear trailing arm bushing, front control arm bushings, possibly Whiteline ALK).
The Swift Spec R's are great springs. I'm partial to our GTWORX springs of course (and biased), especially if you're not going to revalve, but both are great options. If you want to be "competitive" the revalve will be a decent advantage locally. If you are just looking to have some fun, I'd be happy with freshly rebuilt Bilsteins. - Andrew |
Put the Swift spec-r's on the Oem bilsteins. You dont have to worry about getting the bilstein revalved, the Oem valving is just fine. Put the money to something else
The Whiteline sway bars go with the 26mm/24 mm rear adjustable ones. Tweak to get the handling to suit your style of driving. As your driving changes then you can alter the balance of the car a bit to suit. If the rollcenter kit changes the suspension angles, moves the pickup points or has more metal than the original unit, you will get bumped in class in SCCA..most likely to SM ( and you will not be competitive there :-) )... In terms of what it does for the car..definitely yes yes yes, it gives better suspension angles on the control arms up front on lowered cars and on the steering arms. It wont give you negative camber gain in bump but it will help maintain the static camber during the effective range of motion you have up front and tends to reduce the bump rebound steer effect. Check with your local SCCA region and competitors. For friendly competition and fun driving, people wont really care, only the dead serious competitors will complain. SS lines would help you more at the track rather than at autocross, I would get some decent pads like the EBC yellows or blues instead. Yellows if the autocross is just once or twice a year blues if it is like 8-10 times a year. Yellowstuff work extremely well even cold. Blues might need a little warming up in very cold weather. I DD use the Yellows year round even in freezing weather in Georgia. In terms of stopping power Blues> yellows The TRE diff would be fantastic probably the biggest effect of all the mods you have in mind but it does cost a bit and takes time to install. Then again any rear end mod takes time and disassembly/reassembly. If you are comfortable with disassembly/reassembly of the rear end, you might consider the Weir 12 plate mod. It is relatively inexpensive but requires installing in the diff. If the diff has never been touched then it will have the original and incorrect plate arrangement courtesy of Mitsubishi, so you can do the plate re-arrangement and have the diff actually work better as it was designed to, not to cut noise and keep complaints down. No real cost except time for that one. I see you are also going to do the driver mod.. Excellent...for Autocross you might try the Evolution driving schools take all three levels ....in lieu of that find a good local driver...IIRC the SCCA Tennessee Region has several National champions....ask one or more to teach you and let you ride along. If you are decent maybe they will consider co-driving..Seat time counts bigtime. Drivers mod will be worth all the hardware you intend to do. Lastly....power...keep it the way it is until you have the maximum out of the other mods... PS I hope your deployment goes easy and you come back safe and sound. Keep your head down, sir <Salutes > Milburn |
What class are you wanting to run in? You need to figure that out first. It sounds like you are already going to be in ASP because of your aftermarket intercooler unless you go back to stock. If you are new to autox you would probably be much more competitive to drop back down into STU and have a better PAX. In STU you can only do a rear diff restack, not swap to a 12 plate diff. Figure out your class first, then modify within those constraints.
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Andrew / WRC,
Thank you very much for the advice! Reading the SCCA rule book, it places the Evo into two categories: STU and SPA, which one is the Evo most competitive in with the level of mods I want to make? Also, I was trying to determine whether the RCK is not allowed in those classes, but couldn't seem to find the nomenclature to describe what the RCK does... It's probably my lack of terminology more than anything else. I definitely do not want to compete in SM; I did with my other IX and I was sorely non-competitive. Andrew, Will changing all those bushings make the ride overly painful to DD? I'm leaning toward the GTWorx springs, mainly for livability, but is there an overall performance sacrifice by choosing your springs versus the Spec-Rs? Or is it mainly ride height? I looked at the old thread supposedly comparing springs, but it never got around to comparing the Spec-R and the GTWorx. Are there any other upgrades you would recommend? I'd like to do suspension all at one time, with the rear diff being last. |
9!'clipse,
Thank you very much. I'm thinking SPA is where I would go, mostly in how I would like to mod the car for overall fun / performance, while still being slightly more competitive than SM. This is not a dedicated auto-x vehicle, it is a DD car that will see probably 1-2 days a month of auto-x. That's why I'm trying to find a good blend of overall livability, performance, and competitiveness (if such a thing exists) while staying within a decent budget. Do you have any recommendations for SPA? I can't seem to find the section in rules where it says the RCK bumps the car to SM. If it does, I will likely hold of on that mod. |
Originally Posted by charon2123
(Post 10314792)
9!'clipse,
Thank you very much. I'm thinking SPA is where I would go, mostly in how I would like to mod the car for overall fun / performance, while still being slightly more competitive than SM. This is not a dedicated auto-x vehicle, it is a DD car that will see probably 1-2 days a month of auto-x. That's why I'm trying to find a good blend of overall livability, performance, and competitiveness (if such a thing exists) while staying within a decent budget. Do you have any recommendations for SPA? I can't seem to find the section in rules where it says the RCK bumps the car to SM. If it does, I will likely hold of on that mod. Before you spend any money on any modifications, you'll need to decide if you really want to be competitive (or even stand a chance of being competitive) at AutoX or if you're just going to drive to have fun. If you pick your mods first and your Autocross class second, you're going to regret your choice of mods. Invariably some simple mod will push you to a higher class than you want to be in. Keep in mind that very few people actually show up to not be competitive. Either you're going to love it and become competitive, or you're not going to enjoy it and you just won't go. If you want to be competitive without spending a huge sum of money, STU is where you want to be. Even if you had an unlimited budget, I'd recommend starting in STU to learn how to handle the car. For any autocross class, your most important modification is your tires. I didn't see tires listed on your mod list, but for STU you're going to want either Star Specs or R-S3s in 245/40/17. 245 is the widest tire you can use on an AWD car in STU, so use it. The Star Specs and R-S3s are the top choice. Don't cut corners here. The next biggest mod is your alignment. For autocross you want a lot of camber, and a lot of caster if you can get it. With the stock suspension, you can flip the camber bolts to dial in about -1.7 degrees of camber (varies by car) without camber plates. That's the bare minimum, but you'll want more. Get some camber/caster plates to dial in -3.0 to -3.5 degrees of camber and as much caster as you can handle. Next on the list is coilovers. You've made a good choice with the MR Bilsteins and Swift Springs. The sway bars should help, too, but keep in mind that it is possible to go too stiff (depending on who you ask). Beyond tires, alignment, and coilovers, every other mod is going to be a marginal improvement. If you really want to be competitive, don't bother modifying anything else until you've taken care of those three modifications. For STU, the roll center kit, upgraded rear differential, aftermarket intercooler, and any changes to the boost control system or maps aren't allowed. However, you are allowed to restack the differential according to the service manual, which will give you more lockup. You can adjust timing and fueling to increase power, but don't expect to break 300/300 easily without tweaking the boost tables. That said, I doubt you'll miss the extra power that changing your boost would give you on most autocross courses. If you do insist on installing the RCK, keeping your aftermarket intercooler, upgrading your differential, etc. then be prepared to be bumped into ASP or SM. In a reasonably large region, you won't be competitive in these classes without 275 width R-Compound tires, quality aftermarket coilovers, full bolt-on mods, etc. That's not to say you won't have fun, but if you ever get the urge to be competitive you're going to have to choose between unmodding your car or spending a lot of money to push it to the limit. If you stick with STU, that probably won't be a problem, and I doubt you're really going to miss the other mods on the street anyway. That said, I would actually suggest that you not spend a single dollar on any modifications for the time being. Instead, start attending autocross events ASAP so you can get a feel for whether or not you want to be competitive. You'll find that spending money on mods up front isn't actually going to help you drive faster anyway (aside from tires and alignment) because it's going to take a while for your skills to catch up to what the car can do. Once you start reaching the limits of the car, which will take much longer than you think, then you will have an excellent idea of what mods you really want to buy. |
Originally Posted by charon2123
(Post 10314792)
9!'clipse,
Thank you very much. I'm thinking SPA is where I would go, mostly in how I would like to mod the car for overall fun / performance, while still being slightly more competitive than SM. This is not a dedicated auto-x vehicle, it is a DD car that will see probably 1-2 days a month of auto-x. That's why I'm trying to find a good blend of overall livability, performance, and competitiveness (if such a thing exists) while staying within a decent budget. Do you have any recommendations for SPA? I can't seem to find the section in rules where it says the RCK bumps the car to SM. If it does, I will likely hold of on that mod. I have only owned my Evo for a few months but here is what I have done so far: Tires: star specs or rs3's are hands down the best autox tires in STU. However from what I have seen locally, especially with the rs3's, they don't last very long at all. One full season at most. So I compromised and went with the Hankook Ventus V12 EVO which is stil a very good performance tire but will last quite a bit longer with its 280 treadware vs 180 for the others. As far as size either 245/40/17 or 245/45/17. 240 gives you a stiffer sidewall while 245 gives you slightly more gearing. Alignment: 2.1* of camber up front and 1.5* in the rear. I kept toe at zero to prevent wear on the tires. Suspension: Bilstein HD's (which I ordered back in May and are still backordered) and Swift Spec-R's. Drivetrain: Rear diff restack and energy suspension rear diff and mustache bar bushings. Brakes: Centric Premium rotors and Racing Brake et500 pads (ordered) Power: car came with 3" tbe and I added a HFC. Also came with a k&n filter and I added an injen hard pipe. I also fixed boost leaks, new plugs and wires, and am currently tuning fuel and timing. 290-300hp should be pretty easily achievable. As far as the roll center kit, I think that may even put you up in the prepared category but street mod at a minimum. As mentioned even going into ASP gets very expensive to be competitive. STU is very streetable and still a lot of fun to drive. |
Wow! Thank you very much everyone, you have definitely given me a lot to think about. I think I will stick with STU even though I have to un-mod my car a little bit to fit the class. If I am reading the rules correctly, I can change the following and stay within STU (in no particular order):
- Wheels and tires - Springs - Bushings - Sway bars - Camber / Caster plates - Intake - Exhaust (including manifold) - Rear diff (making it the way it was intended) - Tune, but not touching the boost tables Edit: (Would I need to / should I upgrade the fuel system, i.e. Walbro, etc...) But I cannot touch: - Intercooler piping - RCK - Upgraded Diff - Pretty much everything else... It definitely shortens the list of stuff and overall cost, which'll make the wife happy. For those that run STU, when you have the car tuned do you just ask them to leave it at stock boost / nonmodified boost tables, but modify the AFR / timing maps? (brief rant) The rules would be so much easier to read if they specifically said the things you cannot do per class, versus what can be done. Maybe it's just me... Construct, I understand what you are saying. I modded my first Evo without a plan in mind other than MOAR POWAH, and after starting auto-x in SM I realized I was hopelessly outclassed. While fun, it definitely made it a little less enjoyable seeing other Evos or STis in my same class whooping the poop out of me. I'd rather be a little 'un-modded' and be competitve, than go half-way between classes and be outmatched in one and unable to drive in the other. Plus, I don't think the other half would support the cost of what it would take to be competitive in ASP or SM (not yet anyway :). |
Originally Posted by charon2123
(Post 10315227)
Wow! Thank you very much everyone, you have definitely given me a lot to think about. I think I will stick with STU even though I have to un-mod my car a little bit to fit the class.
Originally Posted by charon2123
(Post 10315227)
If I am reading the rules correctly, I can change the following and stay within STU (in no particular order):
- Wheels and tires - Springs - Bushings - Sway bars - Camber / Caster plates - Intake - Exhaust (including manifold) - Rear diff (making it the way it was intended) - Tune, but not touching the boost tables But I cannot touch: - Intercooler piping - RCK - Upgraded Diff - Pretty much everything else...
Originally Posted by charon2123
(Post 10315227)
It definitely shortens the list of stuff and overall cost, which'll make the wife happy. For those that run STU, when you have the car tuned do you just ask them to leave it at stock boost / nonmodified boost tables, but modify the AFR / timing maps?
Originally Posted by charon2123
(Post 10315227)
(brief rant) The rules would be so much easier to read if they specifically said the things you cannot do per class, versus what can be done. Maybe it's just me...
Originally Posted by charon2123
(Post 10315227)
Construct,
I understand what you are saying. I modded my first Evo without a plan in mind other than MOAR POWAH, and after starting auto-x in SM I realized I was hopelessly outclassed. While fun, it definitely made it a little less enjoyable seeing other Evos or STis in my same class whooping the poop out of me. I'd rather be a little 'un-modded' and be competitve, than go half-way between classes and be outmatched in one and unable to drive in the other. Plus, I don't think the other half would support the cost of what it would take to be competitive in ASP or SM (not yet anyway :). The STU rules might feel restrictive now, but unless you're planning to go all out (E85, R-Compounds, etc). then you're definitely in the right place. By the way: Consider starting a thread in the Motorsports subforum to document your progress building the car and at each event. Grab a GoPro to film your runs and post them up. You'll get a lot of tips. |
Lots of excellent posts in this thread!
As mentioned, picking your class first is the way to start and then build from there. And get some seat time. If you want to be reeeally competitive, expensive coilovers are a big boost but we've had many people do pretty darn well with Bilsteins + GTWORX or Swift springs. See SmikeEvo with Swifts and TouringBubble with our GTWORX springs. Tires and good alignment are cruical. With the alignment you'll want to decide if you want a hardcore auto-x alignment and accept some tire wear on the street (and get camber plates) OR an aggressive street alignment and give up a little at an auto-x. Some adjust between events but that's up to you.
Originally Posted by charon2123
(Post 10314779)
Andrew,
Will changing all those bushings make the ride overly painful to DD? I'm leaning toward the GTWorx springs, mainly for livability, but is there an overall performance sacrifice by choosing your springs versus the Spec-Rs? Or is it mainly ride height? I looked at the old thread supposedly comparing springs, but it never got around to comparing the Spec-R and the GTWorx. Are there any other upgrades you would recommend? I'd like to do suspension all at one time, with the rear diff being last. The Spec R's are firm but still ride pretty well. Our springs are the next firmest and with a milder drop you have more travel, but that isn't quite as important for auto-x. I find them to be a little easier to drive fast but there is slightly less roll with the Swift Spec Rs. - Andrew |
Originally Posted by charon2123
(Post 10315227)
Wow! Thank you very much everyone, you have definitely given me a lot to think about. I think I will stick with STU even though I have to un-mod my car a little bit to fit the class. If I am reading the rules correctly, I can change the following and stay within STU (in no particular order):
- Wheels and tires (widest tire is a 245) - Springs (and struts or coilovers) - Bushings (without more metal content, polyurarhane is fine) - Sway bars - Camber / Caster plates - Intake (up to the turbo) - Exhaust (including manifold) (besides the turbo) - Rear diff (making it the way it was intended) - Tune, but not touching the boost tables Edit: (Would I need to / should I upgrade the fuel system, i.e. Walbro, etc...) But I cannot touch: - Intercooler piping - RCK - Upgraded Diff - Pretty much everything else. For all things STU and to ask questions specific to that class or for tips check out the STU discussion thread: https://www.evolutionm.net/forums/mo...iscussion.html |
Agreed with Construct, GTWorx, and checking out the 2012 STU Thread referenced above, just be mindful when you say "things you can change" -Intake... it is NOT up to the turbo, it is to the MAF... soo.. basically pick your filter setup. ;)
I have autocrossed for approximately 10yrs, competively for the last 5, and nationally competitive as of last year. I bought my evo December of '09, ran 2010 season in a local SMS class (SM but on street tires), shook the car out, getting comfortable with the platform (I autoX'd CRXs for years previously)... Ran OEM shocks for most the first season, upgraded rear bar and the diff re-work. 2011 I realized I wanted to see where I stood as a driver, rather than blaming classing/rules for shortcomings. (STU) So although I have the 'wrong' EVO for the class ('04, SSL) I have found that the class limits make for a GREAT daily driver year round (Ohio, so all 4 seasons to deal with)... and a fast 'show up and drive' class car. I would say do the mods that keep you in STU, then if you have $$ burning in your pocket... EVO School, autoX events anywhere you can find them (I drive hours to most of mine).. seat time * infinity. Welcome to the club... |
As mentioned, seat time is key to winning in any class. I'd run STU by putting a stock intercooler and ehxuat manifold back on. Beyond that, tires and wheels and learning how to drive the hell out of it will get you CLOSE to being competetive.
Do that and then just drive it as much as you can. I have been auto-x off and on for years, but this year was the first time I showed up with a mild car with the intention of just improving my driving. It's pretty damn suprising how much time I was leaving out on the coarse. I know I'm still leaving time out there, just far less then when I started this year. A "slower" car actually gives you a chance to catch fundamental mistakes and correct them. If you have all the HP in the world, it feels fast, but you are probably hiding mistakes all over the place with it. |
You'd be amazed at what a stock Evo can do with practice and good tyres.
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