I'm looking for the inlet diameter of the OEM turbo on the Evo, both 8 and 9 and even 10 if you have that information.

This is all part of our research for possible rules changes for 2008. I figured you Motor Sports guys would know this just as well as anyone else.

Also, what are the inlet diameters for the more "popular" bolt-on turbo upgrades? I'm sure there are tons of upgrades, but there are always typically a handful that are by far, the most popular bolt-on options...

Thanks!

Nikolas

 

The inside diameter of the compressor inlet is about 2.02" if you count the conical step down to the compressor wheel.

The outside diameter of the inlet is about 2.53 inches.

-Alex

 

These hints are driving me nuts! How am I supposed to tell people what I want for Christmas if I don't know the 2008 rules?

 

h a ha....

out of curiousity... is the FP green the same size inlet as evo9 turbo?

 

Nils, yes and no. People could try to pass it off since the compressor wheel is different and the housing's casting is the same but closer inspection will reveal that the housing is in fact machined with no conical reduction into the compressor wheel thus yielding a "modified inlet."

 

it'll be interesting to see the rules.... keeping it to oem only turbo would defenitely help reduce overall cost for street tire class guys.

n

 

STi guys are going to hate that!

 

If they are asking about "size" than it's usually pointing towards creating a maximum size per class. So it's not about it needs to be "stock" - it's about you can't be bigger than 34mm etc.

I would assume that if a max size "requirement" is placed in the rules your car will need to be inspected, and sealed like other racing bodies do. So just saying, "look" my turbo is stock won't cut it. They will remove your intake and take a go/no-go gauge and insert it into the turbo, if it goes in you're not compliant, if it doesn't go in, you meet the rules and are good. Then they usually require the system to be sealed that they can verify you didn't swap stuff out.

It's kind of a pain in the ***, we had to go through it all the time with rally cars.

 

Yeah, so far we are NOT leaning towards requiring the use of OEM turbos. But we are researching the possibility of limiting the maximum "size" of the turbo, or "size" of a part of the turbo, each type of engine is allowed to us. i.e. the max size allowed on a 4-cylinder will be bigger than the max size allowed for a V-6 which will in turn be bigger than the max size allowed on a V-8, and so forth and so on...

And this would only be for Street Class.. Modified Class would be pretty much open, as it always has been.

Just trying to tighten up Street Class a bit more and make it less about who can spend the most money..... ;-)

 

^^^Sweet! I am all about that! If you want Nik, you can base the rules exactly off of what my Evo already is, then I don't have to spend any more money. I will send you a mod list. Any ETA on the rules or the rest of the schedule by the way? I know you probably get asked that 100 times a day.

 

If you want to limit power in Street class, you could also restrict everyone to pump gas (91 or 93 octane, depending on where the event is) and ban alcohol injection. That might be a better way to have a level playing field without excluding people who want to participate.

In order to keep participant numbers up and growing, I would avoid as much as possible rule changes that disqualify common street car mods, which include big turbos in the Evo world. If you want to be restrictive in Street class, I would continue your pre-existing rule theme of banning modifications that are rare on street cars but common on track cars (e.g., lexan windows, carbon fiber doors, etc.).

I'm also very interested in next year's schedule. I competed at Summit and VIR and am looking forward to more RTA events next year. The sooner I have the dates the better the chances are that I can attend.

Thanks!

 

lol... nice

 

Nik, I think that the pump gas is an easier way to control power and cheating. Big turbos don't run well at low boost and you'll probably see street cars sticking to small turbos with efficiency maps covering boost pressures attainable by street gas and not race gas.

We do Pro Rally now and controlling inlet diameter will cost you a lot of time and money. Gas is pretty easy to measure. People will have to install a test port as done for SCCA to take samples from. Measuring inlet diameter on Subaru street cars will be next to impossible, nevermind for turbocharged 350zs etc. where the turbos are well out of reach.

Other items I've always promoted for street car class are catalysts and valid registrations.

Even further you could mandate stock turbos and allow open mods in other areas of the engine knowing that the power gains attainable from other mods are not going to be in the ballpark of larger turbos.

Al


Alex

 

What I don't necessarily agree with is limiting to 91 or 93 octane. I say just limit it to restricting the use of leaded fuel in street class. There are a lot of guys who run 100+ octane in their cars just to be on the safe side, especially when we are beating on our cars in 110 degree weather during the summer months. Also, the difference between leaded and non-leaded gas is easier to police between the smell and the white exhaust tips.

 

ok, so the guys that get cool weather want cheap gas.. you wouldnt recommend that if your in socal.... it gets hot, and its suicide to run anything less than 100oct. But restricting leaded gas would be good.

& guys.. lets not make street class boring.. stock cats? no-one around here runs their cat... most street cars are cammed evo9 turbo cars with straight 3" exhaust.. all the way through.

limiting turbo & tire size is more realistic, atleast for us in the south west

n