I got the access port so the initial tune is likely to just be one of the Alta/Cobb stock tunes. I will probably drive down to Austin and get it dyno tuned by Cobb.
For those of you that are running stock tunes, what is your boost behavior as you get around 5500 rpm's? On my car, I am pulling around 17psi and holding that steady until around 5500-5800 rpm's. At that point my car is dropping boost to around 10psi or so. I was initially thinking that I might be having issues with the diverter valve (it's stock and original), but it holds boost from around 3000 up to 5500 so I don't think that is the issue. Maybe this is just normal behavior?
It's hard to remember what normal behavior is when you haven't driven the car in over a year...
But yes boost typically falls off fast in that range on stock turbo/stock tune. If you were having DV issues, you it wouldn't be holding much boost at all.
I am pretty sure it is the stock tune... I do have a dimsport, I will double check that the stock tune is on it now. I seem to remember getting around that amount of boost when I first got the car. With my tune I was pushing around 20psi of boost.
I resolved the issue that was causing the two codes I was getting. Turns out, i'm a *******. There are two seals on the end of the intake cam that seal the oil passage way that operates the VANOS unit. Apparently, when I installed the Schrick cams, I neglected to transfer the seals over from the stock cam. Because there were no oil seals, when the intake solenoid actuated and let oil pressure flow to the VANOS unit, it was just leaking out into the top side of the head.
Anyway, I got new seals, replaced them and the car is now running code free. I stretched it's legs as much as I could around the neighborhood and all seems well. It's going to the track this weekend and well see how well it does under those circumstances.
How many miles were on the engine when you started the rebuild?
The heads looked pretty clean on carbon build up. I have also seen where
an aftermarket ECU was needed for the cam replacement.
Mini wants to walnut blast my valves at 34k miles. So I was thinking of doing what you are doing but trying to use as a 2nd car for fun but still road use.
Keep us informed as things happen. Any thought of larger fuel injectors?
I have mostly been racing Spec Miata and havent been tracking this car very much. That said, the car has been running great with the new cams and ported head. I am running a stock tune from the Access Port with no issues, no codes. The car is very quick.
It's a ton of fun! Texas has a lot of people racing SM, so the turn out for races is very good. I won't get into all the variances in a "spec" class, even with these, spec racing is absolutely the best! You will very quickly figure out just how good you really are.
I am running Spec Miata. There are a bunch of classes that a Miata can run in, but the Spec Miata class is really the only one where there is good competition.
Same for me--I may split a car with a friend who wants to do it--I may be horrible, but he's even worse, so there's that. I think that's the key. Find a co-driver who's worse than you.
But it'll be at least two years before I have the time.
On the other hand, I could do 24 hours of Lemons anytime--had the opportunity last year and passed, no offers this year, but I'm thinking I may try to do that at least next year.
What BTW wrote is exactly what I've heard--fast up front, slow in the back, and most of the good racing is right in the middle, which is where I'd like to be.
Is the bolt on the intake vanos sprocket opposite just like any other vanos, im about to take mine apart and dont know which direction to turn to loosen it.
