Autocross Evo - X Prepared Build
Oct 12, 2007, 03:37 PM
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Autocross Evo - X Prepared Build
So the SM thread doesn't get off topic, I thought I would start an X Prepared discussion.
Now first off my personal goal is not to be national champion or anything. I am building my car the way I want it, and X prepared is really the only category I will fit in by doing so. Therefore I could care less if my personal car is not to the limit of the rules, or if there are better mods I could do first, etc. I do however want to share what I am doing with others (that may have a much better built XP car), and to have an open discussion on possibilities.
Now first off my personal goal is not to be national champion or anything. I am building my car the way I want it, and X prepared is really the only category I will fit in by doing so. Therefore I could care less if my personal car is not to the limit of the rules, or if there are better mods I could do first, etc. I do however want to share what I am doing with others (that may have a much better built XP car), and to have an open discussion on possibilities.
Oct 12, 2007, 03:54 PM
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Actually I am staying with the stock block/turbo for now, but there are other things that would put me there probably. I am messing with the wiring quite a bit probably, will probably have an EMS and run on E85, which will involve fuel system changes...Im relocating by battery...will probably get a carbon fiber trunk, possibly a gutted interior (right now all i have in there is the dash), and various other small things that I want to do, but wouldnt meet SM rules or their intention.
Oct 12, 2007, 11:29 PM
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I'm running XP because of the Cusco power braces, otherwise I'd be in SM. There are a few that run XP in my region...more in SM, but whatever. If I had the cash...I'd prep the motor to rev to 9k, possible twin scroll set-up, although there are not too many here that I know of to check out.
I think the best part of XP is that you can run all the bracing that you want...good luck on the build.
Dennis
I think the best part of XP is that you can run all the bracing that you want...good luck on the build.
Dennis
Oct 13, 2007, 06:27 AM
#6
I'm building my VIII for XP next season. Like you, I have a few things that I want to do and have already done that lands me in XP.
My primary goal is reducing weight as much as possible while staying with the budget.
Interior gutting : Stock dash, interior door panels, and headliner are probably staying for now. Free weight reduction like sound deadening, carpeting, rear seat (front will be replaced by lighter race seats), AC system are going.
Front and rear bumper crash bars are already removed as well as all rear seat belt assemblies and rear wiper and motor. My battery is relocated in the trunk as you plan on doing. I'm looking into some lexan windows and lightening of the doors also.
Powerwise: a geen turbo and supporting mods, running race fuel is what I'm gonna go with for now but future plans includes a stroked motor and built head.
Suspension: coilovers has not being decided yet but I'm leanning towards custom valved Ohlins(old crappy coilovers have got to go), I'm going with 18X10 frt/ 18X9.5 rear wheels. I already have RC correction kit in, all poly-bushings, rear fenders are rolled and pushed etc.
Good luck your XP build and keep us updated.
My primary goal is reducing weight as much as possible while staying with the budget.
Interior gutting : Stock dash, interior door panels, and headliner are probably staying for now. Free weight reduction like sound deadening, carpeting, rear seat (front will be replaced by lighter race seats), AC system are going.
Front and rear bumper crash bars are already removed as well as all rear seat belt assemblies and rear wiper and motor. My battery is relocated in the trunk as you plan on doing. I'm looking into some lexan windows and lightening of the doors also.
Powerwise: a geen turbo and supporting mods, running race fuel is what I'm gonna go with for now but future plans includes a stroked motor and built head.
Suspension: coilovers has not being decided yet but I'm leanning towards custom valved Ohlins(old crappy coilovers have got to go), I'm going with 18X10 frt/ 18X9.5 rear wheels. I already have RC correction kit in, all poly-bushings, rear fenders are rolled and pushed etc.
Good luck your XP build and keep us updated.
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Oct 20, 2007, 10:33 AM
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My first ? to the masses is about a relocated battery.
My thought is to re-locate my battery to where the stock emissions canister is...this is just behind the rear bumper on the driver's side (see pic below).
There is a nice bracket there to place it on (I have a Odyssey 680), and changing it out is a snap (just 4 bolts).
My main concern is if this is the best place for weight distribution...the advantage is that it is lower than if in the trunk, but it is also placed behind the rear axle.
Seeing as this is an XP car I have a lot of flexibility as to where to place it, and if there is some place better i'd like the suggestion.
My planned setup is to have the cable come into the trunk through the grommet already there, into a panel that has my circuit breaker and a disconnect switch (probably a remote one that goes to the rear bumper somewhere), then a distribution block so i can directly wire some things i might have back there, and a large power cable to the front and another distribution block w/ jumper terminals.
My thought is to re-locate my battery to where the stock emissions canister is...this is just behind the rear bumper on the driver's side (see pic below).
There is a nice bracket there to place it on (I have a Odyssey 680), and changing it out is a snap (just 4 bolts).
My main concern is if this is the best place for weight distribution...the advantage is that it is lower than if in the trunk, but it is also placed behind the rear axle.
Seeing as this is an XP car I have a lot of flexibility as to where to place it, and if there is some place better i'd like the suggestion.
My planned setup is to have the cable come into the trunk through the grommet already there, into a panel that has my circuit breaker and a disconnect switch (probably a remote one that goes to the rear bumper somewhere), then a distribution block so i can directly wire some things i might have back there, and a large power cable to the front and another distribution block w/ jumper terminals.
Oct 20, 2007, 02:48 PM
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No. Keep the weight as close to the axles as possible. You will want to center the mass if possible.
I would seriously consider using a mini battery instead. Navid Kahangi (noted SM autocrosser) did a little research and found that the weght of the additional battery cable offset any weight distribution advantages. He did the mini battery in the stock location instead.
On the other hand, if you are looking for more under-hood real eatate (to help with uicp clearance, etc.) , then I'd suggest moving the battery just behind the rear seat, centered on the v-brace.
Think about it this way. The further away the battery will be from the center of gravity of the car, greater force will be generated by the battery as the car rotates due to the high polar moment.
I would seriously consider using a mini battery instead. Navid Kahangi (noted SM autocrosser) did a little research and found that the weght of the additional battery cable offset any weight distribution advantages. He did the mini battery in the stock location instead.
On the other hand, if you are looking for more under-hood real eatate (to help with uicp clearance, etc.) , then I'd suggest moving the battery just behind the rear seat, centered on the v-brace.
Think about it this way. The further away the battery will be from the center of gravity of the car, greater force will be generated by the battery as the car rotates due to the high polar moment.
Last edited by dsmythe2; Oct 29, 2007 at 05:53 PM.
Oct 20, 2007, 02:59 PM
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I am using the Odyssey 680 which is 15 lbs...the emissions canister was 5 lbs. Eventually I will get something like the Braille race battery if I find the odyssey has no issue with starting running everything.
I also thought about just putting the battery where the rear seat was somewhere, so it would be forward of the axle.
I also thought about just putting the battery where the rear seat was somewhere, so it would be forward of the axle.
Oct 28, 2007, 06:21 AM
#11
This is my SCCA autross-legal lightweight exhaust I just finished, so I thought I'd share. It's fairly light (only 7 lbs heavier than the downpipe) and not obnoxiouly loud as the open dowpipe I use to run (NYR autocrossers no longer need earplugs
)
I kept it simple by using a DC sport downpipe with cat delete, a generic 3" race muffler followed by a turndown. Properly welding the O2 sensor bung and putting a capable exhaust hanger at the end was also required.
) 
I kept it simple by using a DC sport downpipe with cat delete, a generic 3" race muffler followed by a turndown. Properly welding the O2 sensor bung and putting a capable exhaust hanger at the end was also required.
Last edited by madmax199; Oct 28, 2007 at 06:39 AM.
Oct 28, 2007, 09:30 PM
#12
My intentions next year are to run the Magnum a few times to get more technically familiar with it. I only looked briefly at the rules but I am fairly sure that is where it would be classed. I have a feeling between the spool of the GT35R and the weight that it won't be the most competitive. I am sure it will be extremely fun to drive though 
Oct 29, 2007, 06:27 AM
#13
My intentions next year are to run the Magnum a few times to get more technically familiar with it. I only looked briefly at the rules but I am fairly sure that is where it would be classed. I have a feeling between the spool of the GT35R and the weight that it won't be the most competitive. I am sure it will be extremely fun to drive though
Negatives should be with the late spool of a GT35R where it will be hurting bad coming out of slowest turns (hairpin type) ; even the stocky sometimes falls out of boost.
Positives are you are capable of putting some serious rubber to the ground wich is the name of the game is this sport. Maybe a stroke 35R set up is the ticket to have the Magnum competitive but regardless it should be a blast to drive
.
Jan 5, 2008, 01:39 PM
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First XP autocross is tomorrow. Right now I am still on street tires and an otherwise fairly stock car. Almost all the interior is gutted out though. Hopefully I will get more XP'ish as time and money allow throughout the year.
Jan 5, 2008, 03:32 PM
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We have a lot of track dates on our midwest forum.
