Sounds like that is incorrect to me. It says: "0472 in. over standard bore and the appropriate standard oversize piston may be substituted." That means you could run your engine at .030 or .040 OVER std. bore. All of us know that when someone makes a "built" motor....030 over is commmon.
You are right the rule might be to allow someone to rebuild/refurbish their motor and still be legal...BUT a motor built under those rules..bored .30 or .040 over with forged pistons, completely balananced, shaved heads for higher compression, and port matched will without a doubt have an advantage....it is a "built" motor for SP. That's all I'm saying
In Mustang "Street Stock" class racing engines are purpose built for that class...but of course they aren't as built as a Mustang running Street Outlaw or Pro Street...but it is still a purpose built race motor to extract every amount of hp possible under the rules. Just because the rules don't allow for as much and it isn't built to the fullest doesn't mean it wouldn't be beneficial and it doesn't mean it isn't "built"
That's all I was trying to say
Back to the topic of STU

 

Correct. It's a built motor. Not as built as some, but still "built".

Just to put some numbers on it, the allowances in SP allow you to change the Evo's motor from a 1997cc, 8.8 displacement ratio, to a 2054cc, 9.0 displacement ratio motor.

Would that show measurable HP gains? Absolutely.

Is it built to the limit of the 4G63? Not even close. Is it built to the limit of the SP rules. Yes.

 

Geez, sorry I even brought it up. I think its easy to see why many don't care to post here, too many ready to make a big deal out of nothing.

All I said (which is correct) that you can't have a purpose built race engine in SP, THATS ALL I SAID. You guys go out of your way to make a big point about what?

You want to split hairs about nothing and pat each other on the back while your at it go right ahead. Adios girls.

 

"Purpose built race engine" doesn't mean the same thing as "no holds barred race engine".

Hell, there are autocrossers who build up engines from individual parts (pistons, rods, crank, cams, etc.) for Stock class autocross.

When you say that SP doesn't allow purpose built engines, you do a great disservice to all of the SP competitors who have invested large amounts of time and money building engines for autocross.

I'm sorry that you are taking it personally. It's not personal -- just trying to clarify for the other readers of this thread the difference between those things you've said which are true (must use OEM cams, rods, crank, etc.) and those which are not (can't have a purpose built engine).

 

Can I run race tires in STU?
I read the rules and it is not clear to me if they are allowed or not.

My bonus check shows up next week and I plan on picking up a second set of wheels and tires. As such I want to know what I'm shopping for. I'd love to get a set of Kumho Ecsta V710s or V700s. But if I have to stay with street tires I'll just get another set of Advans.

Any hints?

 

Can't have race tires. STU stands for street tires unlimited. You have to run a tire that has at least something like a 140 tread wear. The stock Advans would be a great tire for this class. You are also limited to 245 width.

 

Just catback? I think the entire turbo back is allowed right?
At least the cat back and a high flow cat.

 

Exhaust mods allowed in STU are:

- Any part of the exhaust system beyond (downstream from) the header/manifold or catalytic converter, if so equipped, may be substituted... (inherited from Stock).
- Headers, emissions legal. (inherited from STS)
- High flow catalytic converters are allowed, but must attach within six inches of the original unit. (inherited from STX)

No other allowances are made. In particular, the downpipe must be stock.

 

The exhaust rules in STU as they apply to the EVO are very easy.

you still can't touch anything on the turbo!!!

Everything that Jbrennen applies. As for the hi-flow cat within 6" inches of the original..., The EVO has only a single cat. As long as your aftermarket exhaust retains the cat in it's aproximate stock position and provides a bung for the O2 sensor, then your Ok. The intent of this rule was to prevent people from subsituting the cat for a muffler, and to provide the LEV disadvantaged cars such as the WRX (it's got 3 of them) , and the Nissan SE-R (2 cats, one is in the header) a means to upgrade the exhaust.

 

Advans it is. Anybody know where I can get a set of stock Enkeis?

What would be a better wheel that the Enkeis?

 

I've had good results with both the 17x8 Enkei RPF1 and the 17x9 5Zigen FN01R-C. (Both of them in 35mm offset, I think...)

Both are very affordable. Around $1000 for a set of 4. The RPF1 is light, but the FN01R-C will put a little more rubber on the ground due to the wider rim. I'm told that the 17x9 RPF1 won't fit the Evo -- never tried it myself.

If you want to reduce rotational unsprung weight beyond what is possible with lightweight wheels, note that you can also run two-piece brake rotors in STU. These will save you at least a couple of pounds at each corner.

 

Where can you get Enkei's? TireRack does not have them and Discount Tire does not list that model (RPF1)

 

I got them from Nino's Auto Accessories, but that was almost a year ago.

I remember finding plenty of places to buy them online. Do a google search for them. Be sure to look for all three of these "spellings" : RPF1, RPF-1, and RP-F1; I've seen them advertised under all three of those.

 

We went over that time and time again on the scca forums. Changing your downpipe has been found to be perfectly legal by everyone who has a WRX. Its a disputed rule but the official consensus is that as long as you follow the highflow cat rule you can change out all other piping before and after the turbo.

 

I'm looking for a set of gold Enkei RPF1 17x9 too... I'm hoping it will clear the front with a small spacer.