if im gonna do something, id do a TRE.

 

Well, I'm definitely not the most experienced guy out there, I've only been doing this a couple of years, but I'm happy to talk to other Evo guys, and offer whatever information I have managed to pick up. There are some great resources on this forum and in the NASA org on this stuff.

I think your mod track sounds great, the improved camber and higher spring rates will be very noticable. I think you should elevate the rear diff to high on your list, its a huge difference for a relatively low cost. I haven't tried an aftermarket ACD flash yet, but thats on my list as well. If you are modding the rear diff I recommend going to at least a 12-plate diff, if not a full 1.5 way. There is no point in paying the money to swap the stock plates when you can upgrade for so cheap while you are in there anyway. The Weir Performance 12-plate mod was <$200 shipped as I recall and I've been very happy with the performance.

Raptord is right too, don't worry about it being uncontrollable, its not throwing you into opposite lock, it just allows the car to point in under throttle. You may need to swap around your rear sway settings if you are getting too much oversteer, but I haven't had that be the case so far. Like with any mod take it easy the first few laps until you get comfortable with the changes.

 

rear sway will be going to full soft when i add the coilovers anyway.

for any of you guys with the TRE rear, is the HD side cover needed on a road race and never launched car?

 

I agree with jerdeitzel, there is a lot to cover. When i first started, one of the things i learned is gather your own data and become your own expert. As far as mods in general, i try to be patient. Although i know that can be tough. I think the driver is the priority. Also, working on fine tuning your suspension/alignment is critical. When your lap times get decent and consistent then do the rear-diff. From there on you can work on that balance indefinitely. After those 2 i then added a splitter/wing.

If i could have i would have spent even more time/money on myself and gather a lot more data. So id rather have less mods but use more of my budget to invest in myself. Your competitors will have faster cars but in a few years youll have more invested in you which is way more valuable than how many mods you have on your car.

 

100% agree. You should be able to justify the mod on your own. Ask yourself, "Why do I need this?" Don’t just do mods because you "think" it'll make you faster. That’s not how this stuff works.


On a side note, For Road-race application, I really can’t foresee a tighter rear diff helping over a tuned ACD stock setup. Perhaps a better front diff if anything. But that’s an entirely different topic for a different thread.

 

thats where the issue lies. to me, the rear of the car felt too light at the end of last year. and i kept thinking about a wing, but i try to consistently to talk myself out of it. i HATE making big swings at the car that cause me to have to spend an entire day re learning the car, instead of say 1 session to be comfortable again.

of course id also like to discuss that. which are you running? i bought up an extra acd box last year to get it flashed, but kept constantly changing my mind.

 

If you are talking about the stock 8 plates in the correct order, then maybe... but the factory incorrect USDM 8-plate setup is awful compared to a 12-plate or 1.5-way. It's night and day different.

 

The evo8 does need a lot of diff help, more so in the front.

 

well, any thing i see posted about an acd flash even on the stock usdm rear has been nothing but positive.

 

IMO they compliment each other - my simple understanding is that the center will provide more lock to front and rear, and rear diff will provide more lock and thus more torque to the outside wheel

 

Why do i need this? Great question! Thats basically another way to say the same thing. Something else the OP should be aware of. Cars can vary with what sort of mods are preferred. For instance, whats considered necessary for an Evo 8 might not be for an Evo 9. I have an Evo 9 and havent tried any sort of ACD flash yet, but ive heard good things. So you know, when i did the TRE rear-diff, it made for me a significant difference for the better.

 

I guess i always think people have done ALL the other stuff when questions like this are asked. If you do not run a good set of coilovers, have all the diff's working like they should, running a serious race alignment and running "real" tires then i wouldn't even think about aero. Unless you just want to look cool! . Look at the times Nathan (boom) ran at some of the tracks without aero. You don't need aero to go fast!

Has it never been mentioned that tires and alignment are the biggest thing you can do to your car? They will make the most difference.

From running a good rear wing and a "who knows" how good front splitter for 2 years i have seen a .8-1.0 sec per mile increase from aero. I for sure have not optimized the setup and i'm sure there are much better professional setups that would produce a better results. Is it worth the $2000+ to do it somewhat right? That all depends on how you look at racing. Mostly, i race for fun! But, there are sometimes you want to take it serious. And having a car that has the potential is always a good thing.

 

my personal car is a 9. suspension/alignment are already taken care of, minus doing any bushings, and i run rs3's. thats why i tried to target the discussion on the "example" car in the first post, and in my mind any car should have at least that level of setup before considering wings and the like.


so has anyone in here run the acd flash on a stock usdm diff?

 

I guess i should have been talking about your example. That was more just a general "when to add aero thought".

For your setup i would go run slicks before aero. You will gain way more time doing that. I do assume this talk is about when to add aero for competition?

 

the spark to all of this, for me at least, was the new TT 1/2/3 nasa classes. long term goal is to get into the NASA tt competition of course, and id like to set the car up now asn fully as possible, and make no major changes so that i can learn the car as it will be. the real question in my head was would the aero point hit would be worth it.

im not actually planning on adding anything until i sort the majority of other things.