No idea if this in the improper place, but I didn't see any better place.
For you turbo guys out there how do you deal with the turbo though the corner and on the exit? Do you keep your feet on the brake and gas?
Has anyone done any datalogging showing say just normal no brake loading vs brake loading on a turbo autox car?

 

Proper gear selection and a "sixth sense" for throttle control

 

In for responses. I auto-x'd my car for the first time today and it was a bit of a handfull. I feel like half of my problem is due to insufficient tires and the other half is due to me being used to racing Subarus.

 

what tires?

 

There are only two choices for a force fed Miata in Autocross. 1) Hoosier A6 275-35-15 2) Goodyear DOT-R 275-35-15. And I'll just go ahead and tell you....that's not even enough tire. I would REALLY love to be able to run 315'sR and either 285's or 295's on the front.

And I get around the Tubo issues by not using a Turbo

 

ah yeah well its to late for me, a supercharged would be a better deal for a SSM miata most likely.
I ran 225 50 15 toyo RA1's but they were used freebies from a track driver.

 

195 Falken rt615's. The power was doing nothing for me, and I was slow because I kept trying to use it. 225 rs3's and 15x9 6ul's are on the to-do list. R-comps are out of the question right now.

 

bbundy has been regional champion the last year or two. Send him a pm if he doesn't see this.

 

throttle control.

 

I dealt with it by buying a Rotrex.

 

This. I loved auto-x with the turbo motor.

 

With the stroker motor and a 3071R I don't even notice much turbo induced nonlinearities. and its got significantly more torque throught the RPM range you drive in than any super charged dyno plot I have ever seen.

With the stock internal motor and the same big *** turbo I do notice turbo lag and slow spool issies. Takes more throttle control. Some slow corners you can come out full throttle and actually need to lift a little as the boost comes up and you get into the power band to be smooth.

Bob

 

Brakes? What are these things you speak of using for autoX? With the 6spd and 3.9 diff, I never really had any problem falling below boost threshold. I'm just a FMII w/2560 on stock 1.8 (remember 01-05 has 10:1 compression) and was using V710s.

 

If you aren't using your brakes....you just aren't going fast enough. The yellow SSM Vette that runs with your region was at the Shootout yesterday...I think I was @ 6 seconds faster than that car over a 50 second course...and my brakes got a SERIOUS workout. That Vette is no slouch and I'm just a lowly little supercharged car.

 

This. Choose lines that keep you in the boost and if you can't, get on the gas WAY early to get that leaf blower spinning. This got me the win at my last autox vs. 4 guys in well prepped supercharged Miatas

TBH I haven't tried left foot braking. It might work, but I'm pretty sure I couldn't do it smoothly enough to be worth while... maybe with practice.

 

I have no idea if it's still out there on the internet, but Dennis Grant of the Far North Racing site/blog had done some data comparisons of left vs right foot braking.

 

Also, having boost controll by TPS really helps me. My turbo spools fast enough where I dont need to get fancy with teh brakes, but I need to be able to control the torque curve as the turbo spools up, keeping part throttle around corners can keep the turbo moving without dealing with an expotential increase in torque and uncontrollable handling.

 

I just deal with it by throttle control. I plant my foot firmly on the gas before I want power, and then pull back as the turbo spools to avoid wheel spin. Then, as soon as I am pointed straight, I re-plant and shoot forward (or if I planted too early, I shoot sideways). I am pretty good at controlling the power, but I still can't compete with one of the NA miatas in my club. I obviously have a little more learning to do.

 

6 speed with the 3.9 resulted in needing third gear on 95% of the courses. I hated all the extra shifting usually needed at sucky points in the course.

Last autocross I did with the 3.636 I was running out of second and kept trying to make second to third shifts. Was even running the stock 1.8 internal motor down on torque and with added lag. Finally said screw it shifted to third after the first big turn and left it there. Took 1.5 seconds off in so doing. only got beat for FTD by a formula Ford and just squeaked on time by a 700hp E85 powered GTR running 345's on all four corners.

I am kind of making a shift in priorities though. I bought a spec miata yesterday.

Bob

 

Just ran my 4th event in the miata yesterday. China T25/T28 + 1.6 so, I feel your pain. Many corners are a decision between bogging second or trying not to blow the tires off in first, I'm trying to avoid multiple first gear grabs. I haven't gotten good with left foot braking yet in the miata but after playing with brake boosting on the street it seems like you would need so much brake in the corner it would be nearly impossible to get the turn right.

TNTUBA, you should have been in Bristol yesterday. Hope you won some cash at the shootout!