JCH13 - Turbo Miata Build/Auto-X Prep - UPDATE 4/29/2011 MOAR VIDEO!

[Aikouka]

My one fear of trying autocross is that I'll just see a sea of cones and be all, "durr, where do I go?" I'd rather do poorly than look like an idiot .

 

[jlee]

My one fear of trying autocross is that I'll just see a sea of cones and be all, "durr, where do I go?" I'd rather do poorly than look like an idiot .

Heh, yeah. I took a LONG time on my first run when I went last year. It's fun, but I'm not sure I prefer it over drag racing - I'd rather go really fast for a little while instead of murdering my tires going 40mph.

Maybe when I run the MR2 instead of the Forester, I'll feel differently.

 

[Aikouka]

Heh, yeah. I took a LONG time on my first run when I went last year. It's fun, but I'm not sure I prefer it over drag racing - I'd rather go really fast for a little while instead of murdering my tires going 40mph.

Maybe when I run the MR2 instead of the Forester, I'll feel differently.

I've never really had much interest in drag racing. It certainly takes some skill to perform well in drag racing... no granny shifting . I think I'd prefer track/circuit racing, where the road is much easier defined. In any sort of course, I'd imagine you don't test just your shifting capability, but also your knowledge of your car's capabilities in relation to the course.

Although, I don't think there are any tracks around here other than Talladega... but I like right-hand turns too .

 

[JCH13]

My one fear of trying autocross is that I'll just see a sea of cones and be all, "durr, where do I go?" I'd rather do poorly than look like an idiot .

That's why god gave us free instructor ride-along! Once you're actually driving the sea of cones becomes a bit more manageable, but like JLee said, most of us take a bit of a granny run our first time out to make sure we know where the course is, even if we've memorized it from walking it.

 

[jlee]

I've never really had much interest in drag racing. It certainly takes some skill to perform well in drag racing... no granny shifting . I think I'd prefer track/circuit racing, where the road is much easier defined. In any sort of course, I'd imagine you don't test just your shifting capability, but also your knowledge of your car's capabilities in relation to the course.

Although, I don't think there are any tracks around here other than Talladega... but I like right-hand turns too .

I'm doing that next month (Summit Point) - but I'm a little afraid of running my own car on a road course...don't want to crash

 

[JCH13]

So the time has come for me to bite the bullet and put a real exhaust on my Miata. The side-cut is pretty cool, but the extreme noise and limited ground clearance are really starting to detract from its enjoyability.

Originally I thought that I'd build a turbo-back exhaust, but to save $200 it will really cause a lot of headaches and make life generally much more of a pain in the ass. I am going to buy a race pipe (cat delete) and a cat-back exhaust and build my own down-pipe. The question is: do I go single turbo exhaust from Enthuza? Very popular with turbo Miata owners, probably very light too. Or do I get the dual turbo exhaust from Flyin' Miata? Lifetime warranty, FM sells great equipment and treats you well, I'd have a dual exhaust system :awe:, and it's on sale.

Thoughts?

 

[Zargon]

I'm doing that next month (Summit Point) - but I'm a little afraid of running my own car on a road course...don't want to crash

its called 8 or 9/10th

start out not pushing at all, and get a feel for it. then ramp it up

staying on street rubber helps, because they are WAILING well before they will lose grip. most race rubber I used didnt make a peep, till it was too late :awe:

 

[FuzzyDunlop]

So the time has come for me to bite the bullet and put a real exhaust on my Miata.... ...Thoughts?

Whats the added weight of the dual. If its not even a noticable weight difference, I'd go dual tip because I like symmetry.

 

[JCH13]

Whats the added weight of the dual. If its not even a noticable weight difference, I'd go dual tip because I like symmetry.

Maybe a few pounds, but not more than 10 I think. :hmm:

 

[Howard]

Maybe a few pounds, but not more than 10 I think. :hmm:

Weight at the bottom isn't that bad anyway...

 

[PseudoSport]

My vote is for the 3” Enthuza :biggrin:

 

[JCH13]

While I ponder exhaust options I decided to implement the boost control solenoid.

SO. MUCH. WIN.

I tightened up the waste gate actuator and plumbed in the boost control solenoid. I noticed a few more PSI before peak boost, then 10-12 psi in boost with a very conservative waste gate duty cycle map. Let's see what this puppy can do...

 

[exdeath]

Wtb burnout video. rrrRRR-PSH-PSH-rrRRRPSSSH-pSHSHSHSHSH-RRRrrrrrrrrrr.

 

[JCH13]

Could go with something like this:

 

[exdeath]

*pop*

 

[JCH13]

So, in reverse order, we have...

1) Exhaust decision. I am going to modify my existing exhaust instead of buying a new one, mostly for $$ reasons. This will free up some alotted "car budget" so I can buy a set of C1M wheels to put some racing slicks on. They'll bump out the front and rear track a little bit, and will drop a few pounds of unsprung, rotating mass on each wheel. Don't worry, I already have the slicks. I am going to make an exhaust like this one, I even have that muffler already! It should shed a few pounds and be a lot more streetable in terms of ground clearance and noise in addition to costing basically nothing, triple win.

2) When I modify the exhaust I've decided to go with a smaller hotside housing to improve turbo response, which means a whole new turbo. I am going to get another T3 turbo, but with a 0.48 AR housing instead of a 0.63 AR housing. It should spool to 12-14psi by 3500 RPM or so (instead of 5500RPM D which will be very nice for auto-x. Again, I'm going with a cheaper china-charger. I just can't justify so much $$ for something I want to swap in and out and that really doesn't get too many miles on it. For reference, here is a .48 AR housing next to a .63 AR housing.

But wait! I have a .48 AR housing! Why not use that? Well, unfortunately, careful inspection showed that this Garrett exhaust housing has a nice crack in it, reaching from the waste gate port nearly though to the outlet.

3) JLee and I did some data-logging today on an 18% grade hill near my apt. The nice steep hill keeps the engine under load so that 2nd gear pulls actually build boost, and there are some epic turns. Also, hardly anyone drives on it and the pavement is REALLY smooth. It's my new favorite spot for pulls and data logs. Here is the video, I apologize for the wind noise and poor view in advance, I still sorting out camera locations.

http://www.youtube.com/watch?v=kcBBxRumgtc

 

[punjabiplaya]

good choice, I don't understand people running +4000rpm spooling turbos for auto-x

 

[Howard]

Could go with something like this:

Is that what I think it is?

 

[JCH13]

Can a mod please change this thread title to "JCH13 - Turbo Miata Build/Auto-X Prep" since editing the title apparently has an expiration date...

 

[JCH13]

After some really weird symptoms on the interstate last night, I sought some advice from some guys who know way more about MegaSquirts and Turbo Miatas than I do. They caught a problem I've been unknowingly surviving... timing fixed at 10deg advanced. All the time. I fixed the mistake in the MSQ file and oh hey... SO NICE TO HAVE A CAR WITH A REAL SPARK MAP. Derp.

 

[Zargon]

LOL nice.

 

[punjabiplaya]

damn, those [edit: NA] miatas can be so beastly

http://www.youtube.com/watch?v=62_890RnQ8I

there's a couple of epic builds going on in MSF

 

[Howard]

damn, those boosted miatas can be so beastly

http://www.youtube.com/watch?v=62_890RnQ8I

there's a couple of epic builds going on in MSF

That's an NA Miata?

 

[punjabiplaya]

damn nm, that is NA

 

[JCH13]

damn, those [edit: NA] miatas can be so beastly

http://www.youtube.com/watch?v=62_890RnQ8I

there's a couple of epic builds going on in MSF

NA as in first generation and NA as in naturally aspirated too :sneaky:

Wicked cool video, the patriot course is pretty intense, a lot of off-camber turns and elevation change. I wish I had gotten more laps in when I raced FSAE on it, fucking throttle fell apart on my first lap D: