Car rules and preparation for a "Street" Class car

[nnywg]

Street prepared/Street Mod are the cut your fender for stupid wide tires class...

Some of us can fit 10.5" wide wheels without cutting fenders.   

[Terry Johns]

My 2 cents worth would be, keep it stock and fix the nut behind the wheel. RE71 R, sway bar and a set of konis will transform the car and still run in BS

[Jackal]

My 2 cents worth would be, keep it stock and fix the nut behind the wheel. RE71 R, sway bar and a set of konis will transform the car and still run in BS

The flabby bit behind the wheel is always the biggest factor.  I'm sure if I gave the car to Ryan,  Cam... or any others on that side of the leaderboard,  I'd see very different results.

[Terry Johns]

That is also the challenge for the rest of us. As for me I shan't be doing any mods to my Mazda that takes me out of C street.

[rairdan93]

A good set of brake pads can really help as well. I'm not sure what the best pads for a Z4M are but carbotech or hawk hp plus pads seem to be the most popular in autocross on other cars. They cause a lot of heat so having a high temp brake fluid will help keep your brake pedal firm and consistent as well. It never hurts to search for other forums on the internet to find out how guys are setting these cars up south of the border.  There is a good chance that someone has already done the homework for this car and has a good base line set up to begin with.

[Stuart]

Just thinking about the SM comments, I think the Z4M would fall into SSM.  What's better than being in a Super class?

[Jackal]

A good set of brake pads can really help as well. I'm not sure what the best pads for a Z4M are but carbotech or hawk hp plus pads seem to be the most popular in autocross on other cars. They cause a lot of heat so having a high temp brake fluid will help keep your brake pedal firm and consistent as well. It never hurts to search for other forums on the internet to find out how guys are setting these cars up south of the border.  There is a good chance that someone has already done the homework for this car and has a good base line set up to begin with.

Brakes are one of the first things on my list. The braking was a bit weak these last couple events.

There is so much info available on these cars it's tough to sort through it all really.

My current list to stay in class, likely in order of appearance;

New tires and wheels
New brake pads and fluid
Alignment
Cat back exhaust (resonator delete)
Front sway bar

[Jackal]

Just thinking about the SM comments, I think the Z4M would fall into SSM.  What's better than being in a Super class?

So it's omitted from Touring and Street Modified. Geeze!!

[Reijo]

SM - sedans/4-seaters.

SSM - 2-seaters ...

And, yes, some cars do not have a place in Street Touring, although the Z  (corrected) is allowed in STR ....and let's not forget BSP,
R

[Reijo]

Look in here:

http://cdn.growassets.net/user_files/scca/downloads/000/017/206/2016-8-23_Appendix_A.pdf?1471970139

[MurrayPeterson]

Brakes are one of the first things on my list. The braking was a bit weak these last couple events.

The braking issue was most likely your rubber.  Get better tires and you might be amazed at how good your brakes are working.  I run a ceramic pad for cold performance (first run) and sharper initial bite than the OEM, but there isn't any more maximum braking available compared to the OEM pads.  I run OEM brake fluid, and have yet to experience any fade or softness at autox, even with two drivers.

My current list to stay in class, likely in order of appearance;

New tires and wheels
New brake pads and fluid
Alignment
Cat back exhaust (resonator delete)
Front sway bar

I would argue that your best path would be this order:
Tires + alignment (this will be your biggest gain)
Brake pads
Sway bar
Adjustable shocks (to help with some of the handling issues usually caused by the sway bar)
Wheels (mostly for diameter change if it is helpful for your car) (don't forget about the rules WRT wheel size and offset)
Exhaust

Be careful with the exhaust change; you may end up with a car that is mostly undriveable on the street.  Or one that exceeds the sound limits.  And it will probably give you the least improvement of the entire suite of changes.

[Stuart]

SM - sedans/4-seaters.

SSM - 2-seaters ...

And, yes, some cars do not have a place in Street Touring, although the Z  (corrected) is allowed in STR ....and let's not forget BSP,
R

Unfortunately he has the Z4M, so is excluded from STR.

[Reijo]

Ah, I did not realize that......the M is classed differently.

Have to watch those high perf. models ... just like the S2000CR is in AS instead of BS like the rest of the S2000's ...

R

[Jackal]

Firstly, thanks everyone for the help. Damn fine community we have here. 

SM - sedans/4-seaters.

SSM - 2-seaters ...

And, yes, some cars do not have a place in Street Touring, although the Z  (corrected) is allowed in STR ....and let's not forget BSP,
R

That all makes sense. I don't have a hope in hell of competeing in SSM on my budget. Lol I think I'll avoid that class.

Brakes are one of the first things on my list. The braking was a bit weak these last couple events.

The braking issue was most likely your rubber.  Get better tires and you might be amazed at how good your brakes are working.  I run a ceramic pad for cold performance (first run) and sharper initial bite than the OEM, but there isn't any more maximum braking available compared to the OEM pads.  I run OEM brake fluid, and have yet to experience any fade or softness at autox, even with two drivers.

My current list to stay in class, likely in order of appearance;

New tires and wheels
New brake pads and fluid
Alignment
Cat back exhaust (resonator delete)
Front sway bar

I would argue that your best path would be this order:
Tires + alignment (this will be your biggest gain)
Brake pads
Sway bar
Adjustable shocks (to help with some of the handling issues usually caused by the sway bar)
Wheels (mostly for diameter change if it is helpful for your car) (don't forget about the rules WRT wheel size and offset)
Exhaust

Be careful with the exhaust change; you may end up with a car that is mostly undriveable on the street.  Or one that exceeds the sound limits.  And it will probably give you the least improvement of the entire suite of changes.

I plan on 18's for next season, which were an option for the Z4M. The tires will have to wait until then as well. I should have actually placed the tires and wheels last on the list I posted before. My bad. Unlimited budget and the wheel tire upgrade would already be done.

Quick clarification. As I understand it, converting to studs is not allowed, but longer bolts are if required to compensate to stock offset. Is that correct?

I wanted to take care of the little things before then though brakes, alignment, exhaust for a few extra HP, and the sway.

[Reijo]

Something to keep in mind:  If you go to larger diameter wheels, you may be increasing your unsprung weight which may not be an increase in performance ... more weight, spinning mass = less acceleration and less braking, also they may be taller which can affect your gearing.  Even the weight of the tire will be more. 

For autox you might be better off with a smaller diameter wheel if you can get the width of rubber you want and the wheels fit around the brakes ... and your gearing works out etc.

IN fact, I know of people downsizing brakes for autox to save unsprung weight (rule-of-thumb - save 4 lbs = 2x4 = 8 lbs equivalent of sprung weight) since you do not use the brakes very much ... we probably use them more than most due to the long airport runway at Fort Macleod.
Lots to think about there.