Making the perfect STX Mazdaspeed... think tank starts here.

[DistantTea]

Yeah the mazdaspeed is a great D stock car, but it has limitations that make it not as fun on the street as some other cars. Plus you gotta beat a Type R whenever you can.

So here's the idea. What would it take to make the perfect STX legal autocross mazdaspeed? Parts have to actually exist and links to those parts would be great.

The STX national champion car last year was a 220HP+ Integra Type R. To beat it the mazdaspeed has to up the ante within the STX rules. A short list of rules can be found at www.moutons.org if you aren't familiar.

I could be wrong but I think we're aiming at 200HP with an emphasis on torque and engine response to beat the Type R where it is the weakest... low end grunt. We also need to lose at least 200 lbs from the car. Things like CF hood are legal... so lets see what we can save.

So lets see what we can come up with... money is not an object... but the rules are.

 

[Ryan]

weight loss hrm... go cf hood, lighter wheels, remove all non essential parts (ac and heater box, carpet, back seat) form the car.. drop the spar tire and jack.

My goal tho would to be to keep the car luxury wise meaning still have ac and heater and carpet and backseat.. but bring in the power and torque to make up for it. thats just me tho.. i wouldn't wanna gut out my car.

 

[DistantTea]

Its still a street car... hell most people's daily driver. I don't think anyone wants to lose their AC or stereo... maybe a lighter stereo though...

 

[Ryan]

stay factory sterio wise.. hey were u by anychance at hyperfest in west va? i saw a msp there with the liscense plate tag pops1cl or somethign to that effect i thought about u when i saw it LOL...

 

[scapamouche]

First thing: CF hood is NOT NOT NOT legal. Put one on and you go straight to Street Modified.

You cannot change the boost, so the easy fix for power (Joe MBC) is also out.

What you CAN do for power in STX:

Intake up to the MAS as long as you don't have to cut any plastics or metal to make it fit. We're good to go with the Injen CAI. I wonder if AEM will do one as well. On Celicas, the AEM CAI is better for autox because it helps with low end torque as well. I wonder if an AEM CAI for the MSP would also help the bottom end more than Injen. Worth thinking about...

Header. N/A really, with the turbo setup...

Downpipe: Legal, and we can remove ALL the cats and replace them with a SINGLE unit. That's not smog legal, but it's ok for STX. You'd also need one of those O2 sensor fake out kits, or you'd have a CEL due to the change in cat configuration and emissions profile.

Cat-back exhaust: Free, just like DS. There's probably some power here once the downpipe bottleneck is removed.

Reprogrammed ECU: OK as long as it fits in the stock housing (ie, is REPROGRAMMED, not REPLACED) and doesn't affect the boost. I think we're luckier than the WRX folks here since the ECU doesn't affect the boost directly. Hopefully, we can get someone to make a good PROM flash for us that makes the most of the engine.

Piggybacks: I think computers like the superAFC are ok, so use that to lean the engine out for more power. You've got to be careful, though, not to go too far...

Short shifter: OK, but I don't think we need it.

Suspension: Here we can use some help. In my experience the car will PUSH and the lack of camber we all know about. Stiffer springs are obvious, too. There are no stand alone struts for the MSP yet, but there are good coilover kits (like JIC.) I am thinking about talking to ground control about d=finding or revalving a set of Koni inserts for stock class. I'm sure it would be easier for them to come up with a good STX coilover combo using those inserts... We could also use more rear swaybar. There is an infinitely adjustible rear bar that I've seen used on P5 to GREAT success in STS. Maybe that's the ticket for us too...

Camber/caster plates are a MUST... or wait till next year when crash bolts are legal for ALL STS/STX cars, regardless of factory permissions...

Tires: I think 17s would be a mistake. It would be MUCH easier to fit a 225 (or maybe even 235) section width on a 16" or even 15" rim... I think 245s are out for us...

As for what tires to use, 225/45-17 Falkens work, but not all THAT well. I speak from experience here... I keep hearing RAVES about the Kumho MX, and the BF Goodrich KDs are the only tire to beat the Azenis in magazine testing (grassroots motorsports last year, and not by much) The MXs are Azenis cheap, the KDs are twice as much. In favor of these two, they come in a MUCH wider variety of sizes. The Falkens are only 205/50-15, 205/55-16 or 215/45-16. The 225/45-17 is the shortest 17, and it's too tall: rubbing and the gearing takes a big hit...

You can also install ANY seat you like, as of next year, as long as it weighs 15 lbs. There are LOTS of good racing seats that fit the new rules, for a decent price.

There isn't much lightening we can do. AS the rules stand, we can swap parts with any other car on the same SP line as the MSP. Unfortunately, there are NO other cars on the same line. In fact, there may not be ANY entry in SP for the MSP yet. Probably the biggest savings would be wheels& tires (I saved 9 lbs per CORNER with the 17x7s and Kumho Ecsta V700s I have now. Imagine using a lightweight 15" rim. You could save 10-15 lbs per corner of UNSPRUNG weight. You could also remove the amp/sub assembly from the back. Unpopular, I know, but probably good for 20-30 lbs... You can't take out the interior panels, or sound deadening, or rear seats. Probably the light DP would save a few pounds, as would an exhaust like AGR and Memphis Racer's HSM unit.

There's MY input. If I can't find a solution to my tire issues in DS, this is probably the path I'll follow next year...

 

[eMKay]

On the subject of shocks, is there any word on Koni making some for our cars? I know Tociko is coming out with some illumina's for them but word is they are not even close to Koni's for autocross.

 

[DistantTea]

Looking over the rules I could have sworn CF hoods were legal... I guess they aren't. Hmmm.

Scap, I still can't see how your car is understeering so much. Ours is an oversteering hero... I don't know how to drive it that way though so I usually end up spinning or weeble wobbling from overcorrecting.

Maybe its just our driving style... so to get more oversteer all you need to do is learn how to drive more poorly

I just don't think the car is going to do good in STX. I don't see it competiting well at all against other cars with superior setups.

I also don't agree that the D stock ringer will be the 330i. I can see it doing well, but I don't think the old Type Rs are going to sit down for that fight. I mean the 330ci has been out for years and its never really caught on for autocross. I don't see any reason for it to start being popular now.

 

[dmitrik4]

keep in mind, it will be extremely tough to make a nationals-winning STX car AND keep it a comfortable daily driver.

...unless it's a cooper S.

your best route is to save all the weight you legally can, esp at the wheels. make sure you buy a rulebook, and keep your checkbook handy/ b/c it ain't cheap.

how is the MSP doing in DS this year?

 

[scapamouche]

Looking over the rules I could have sworn CF hoods were legal... I guess they aren't. Hmmm.

Scap, I still can't see how your car is understeering so much. Ours is an oversteering hero... I don't know how to drive it that way though so I usually end up spinning or weeble wobbling from overcorrecting.

Maybe its just our driving style... so to get more oversteer all you need to do is learn how to drive more poorly

I just don't think the car is going to do good in STX. I don't see it competiting well at all against other cars with superior setups.

I also don't agree that the D stock ringer will be the 330i. I can see it doing well, but I don't think the old Type Rs are going to sit down for that fight. I mean the 330ci has been out for years and its never really caught on for autocross. I don't see any reason for it to start being popular now.

Have you LOOKED at any of the NT and ProSolo results this year??? The 330 is cleaning up in DS....

There is a proposal to move it to BS for next year, in which case the ITR will probably go back to being top dog, but right now, the car du jour in DS is the 330...

 

[Logan]

I've talked to Mazda Motorsports about this car.
Specifically about stock classes for Ontario (our rules are changing for next year).
They told me NOT to change the struts (free mod).
I was told the only thing they wanted to do but weren't allowed was use a larger rear sway bar. I've ordered the 21.5mm AWR adjustable bar. It's one prep point, and I have two to work with.
We'll see what happens next. Hopefully it will be here late this week or early next.

 

[DistantTea]

Nah its still the driver that counts in D stock. It all depends on who shows up. We'll see for sure at nationals.

I was checking the results for the tour... looks like they didn't sell anything but WRX's in Houston... heh.

Check the toledo results to see what kind of drivers we have in my neck of the woods. John Souder placed 7th at the tour in a completely unmodded street tire clad MSP against a hoard of Hoosier clad ITRs... then a freak'n talon takes first? WTF?

I agree that the 330 is going to be a good D stock car, but I think the MSP is a great D stock car right out of the box and has what it takes to be a champ car.

I think the influx of 330ci wins are simply because a lot of top level national competitors are switching to them. If one of those super fast ITR drivers would give the mazdaspeed a try I'm sure it would do quite well.

 

[rowan]

Wow, no CF hood. That's a stupid rule.

Here's my list just for fun .. not that I even drive a Mazdaspeed!

JIC coilovers
15x7.5 rims with 225 tires
forged lug nuts
a good race seat and harness
downpipe and exhaust system
find some cold air for the intake
might as well get a b&m shifter and get some better tranny fluid in there too
bigger rear swaybar
s/afc or some other way to adjust as you see fit

 

[cjstringer]

On the subject of shocks, is there any word on Koni making some for our cars? I know Tociko is coming out with some illumina's for them but word is they are not even close to Koni's for autocross.

Koni will not be making a shock for the Proteges. I spoke to the guys at Nationals last year. They said they did all the R&D on the MP3, and when it came time for production, Mazda took the designs, went over to Tokico, and asked for a cheaper version to be mass produced.
Koni has since said F@ck Off to Mazda in the protege camp. I'd be pissed too. they got screwed. Don't count on them doing anything anytime soon.

 

[cjstringer]

Just a question, but for those trying the 15x7.5" rims, what offset are you using for a 3rd gen, and does it require and fender roll? I am considering the move to STS to get started and want to know what some good, inexpensive options are.

 

[DistantTea]

15" wheels? Unless you get some high profile tires that could seriously drop the gearing for these cars couldn't it?

I mean just going from 215/45/17 to 205/40/17 dropped the top of my second gear from about 60 to about 56mph. I couldn't imagine what the gearing would be if you dropped down another two inches.

 

[CRDMS1]

15" wheels? Unless you get some high profile tires that could seriously drop the gearing for these cars couldn't it?

I mean just going from 215/45/17 to 205/40/17 dropped the top of my second gear from about 60 to about 56mph. I couldn't imagine what the gearing would be if you dropped down another two inches.

I just purchased a used set of 15x7 Kosei K1 wheels (+45 offset) with 225/50/15 Victos. IMHO, this wheel/tire combo doesn't change the gearing so much that it's harmful for autox. The overall diameter is ~1" less than stock. I experienced very slight rubbing over hard bumps only while heat cycling the tires on city streets. The total wheel/tire weight is ~8lbs. less per corner. Wider meats, less unsprung weight, and less rotational inertia can't be a bad thing, right

The fastest car I've ever seen at an autox was a Miata w/13" wheels and Hoosiers. It beat 68 other cars of almost every type by almost a full second. It looked and sounded like a go-cart but the thing absolutely flew around the track.

My first autox with these wheels and the Injen intake is this weekend. I'm also considering installing the MBC before, but not sure if I will or not. This is a club event, as are all the autox events I attend, so there are less limitations on mods for classification purposes.

Peace...(hippy)

 

[DistantTea]

Interresting... keep us updated on how that autocross goes.

 

[rowan]

If you want perfect wheels ...

WEDS Sport TC-005
15x7.5 +45 mm
http://www.weds.co.jp/products/wedssport/tc-005/index.htm

 

[Micaspeed!]

Ok guys, I am in on this one. I have been waiting for a thread like this. First, I have to say I have quite a bit of background with rear drive suspensions (www.delsingmotorsport.com). But am now learnig the fwd set up. Have about 10k miles on my speed with both myself and my 16yr old son doing ds in local ax's. Took a few firsts, but had to drive the dailights out of the car, fighting understeer and worn outside edges of the tires. Not the way I like to do it.
Just came back from Road Atlanta with a mission to meet the team guys and find out how they make the back end come around well enough to compete like they do. Got lots of underside suspension pics and info. I believe we can take the same design intent and scale it down to a great stx car.
Here is what I have gleaned. Make the rear super stiff. All the road guys are running huge rear bars with almost stock fronts. Of course we can not run the same set up and still drive daily with it, but you have to take what they are doing as viable base line. Much heavier spring rate in the rear. Lots of neg camber up front, not as much in the rear. Equal track front to rear. Our cars have a wider track in rear than in front. I am working on this to quantify it and a remedy. I mean, the road guys run stock toyo ts1's shaved for dry, full for rain. These are street tires! Pressures about 39psi cold. But they have the car set up properly. We can do this.
I am not saying how I did it yet, but I just set the alignment to the following: -2.2 deg front, 0 toe front, 3deg caster, rear camber -1deg, toe 0.10 . I did not get a base line prior to doing this , but it was as delivered stock.
With the stock 10k worn Bridgestones, 38 psi, the car is already scary fast around turns. Just with the alignment! I can now get on the power way sooner and the thing turns in like crazy. The steering feel is much better, no more tippy feeling, tracks straight and feeds bak much more confidently.
In DS, I did not want to do the Bandaid solution of stickier tires and other wheels. So I am looking at STX also. I will be figuring spring rates and talking to dampener people. Met the Mouton guy who said they are offering a more affordable line called the Club Sport. Waiting for more info.

Godspeed!
Dave

 

[scapamouche]

How did you get the camber? I assume you used camber plates or crash bolts, but if there is a DS legal way to do it, I WANT TO KNOW!!!!!

Did I mention above that I CORDED a set of Kumho Ecstas in FOUR EVENTS!!!!! UGH!!! I think it's all due to the lack of front camber...

I had thought of running a MASSIVE front swaybar in the car to get rid of the body roll, and help the tires, then use toe out or pressures to correct the understeer the bar would cause, but I'm already having push issues (55f/36r last weekend!!!! Just to get the car BALANCED...)

OK, I'll stop the DS hijack now Back to our regularly scheduled STX... But now that I think about it, I wish STR was still out there! Hee Hee.... ST mods, r-tires (I know I know, that's usually called Street PREPARED, but so what... )