shinronin

here is my situation. last year a new street touring class was added for scca solo2 (autox) called STU which finally provided a home to the S. however, it also provided a home for the e36 m3 and rally cars (STi and evo8). this year, typically i place 3rd behind the 2 STi's who regularly autox. i must beat them. rest assured i'm always working on my driving skills, but my hardware isn't remotely close to rally car levels. yet.

here's what i can do to the engine legally:

* air intake, up to, but not including compressor inlet, may be modified or replaced
* exhaust manifolds and headers be replaced with emissions legal alternates
- relocation of O2 sensor on header is allowed
- alternate O2 sensors, including heated types, are allowed

here comes the kicker...
* boost levels, intercoolers, and boost controllers may not be modified
- boost changes indirectly resulting from allowed modifications are allowed, but directly altering or modifying boost or turbo controls, either mechanically or or electrically is prohibited

* altered engine controls may not alter boost
* electronic components may be installed in-line between engine's sensors and ECU
- electric components may alter signal from sensor to affect ECU's operation of engine management
* FPR may be replaced in lieu of electronic alterations to fueling system
- electronic modification of fueling system not allowed if FPR is replaced
* ignition timing may be set at any point on factory adjustable distributor ignition system
* mass airflow sensor must remain in approximate location
* pulleys and belts of same type as stock may be used
- allowance applies to accessory pulleys e.x. alternator, water pump, power steering pump, and crankshaft drive
- any crankshaft damper or pulley is allowed
* non-metal engine mounts are allowed in factory locations
- volume or metal in replacement cannot be increased

so... i can change fuel (FPR) and timing. i can remap the stock computer, but i can't order more boost. i can add interrupters and piggybacks. what's the best recipe? i always follow lemmi threads, but i don't pretend to understand it all. those willing to help will be rewarded with copious amounts of beer. ^_^ seriously. the rally cars must submit to the powah of the S. *evil grin*

-M3=Lunch-

and im not talking run of the mill tracksport and stoptech...

more like penske's and alcon 6 pot's

shinronin

i have a mod list that i'm workin' through, but i need to catch up in the power dept. i can't make up 6 secs. (my gap from 3rd to 1st place last autox) through driving alone.

shinronin

the rally cars' raw speed is nutty.

JoeyJoJoeJrShabadoo

You can definitely reduce unsprung weight with better brakes though

NoahD

that is, regarding power to weight ratio, you're not going to get more than another 10-15hp with the allowed mods, so you'll still have less power (35 vs. STI, 11 vs. Evo) and more weight than the competition.

It seems that the approach has to be the driving (duh, but you've already mentioned that you acknowledge this) and the handling/braking. This is the tough part. I don't know what the class restrictions are on transmission mods, but you could go for a 4:1 torsen and rear LSD, both of which would help you be able to get on the throttle sooner, assuming these are allowed mods.

Also, get the lightest and smallest-diameter wheels you can legally run.

Aside from that, it seems like the S4 is probably outclassed in this class. Them's the breaks with class boundaries. The S4 is so far removed from an autoX car that it's not even funny. If you're even competitive you should be proud of itself.

shinronin

i agree brakes aren't going to buy me much time if any. they're track day investments. =)

believe me i don't discount the 90% driver, 10% mod slogan of autox. but prepping a car to the max or close to the max for a class is always handy given equal driver skill.

JoeyJoJoeJrShabadoo

probably cheaper and more beneficial than non-substantial power gains. Diff work would help, and better shocks.

shinronin

i'm hoping that with a turbo back exhuast, a crushed 4 or 5 bar fpr, intake (evo, rs4), 85-90mm maf, etc., plus lemmi will net me some good gains. i should prolly email mr. homebrew homeboy himself for his input.

i follow the rules to the letter except when it comes to the tranny. the rally cars have _3_ diffs so i will have at least 2. the dusty lots we autox on in the philly region really favor AWD and their 3 diffs are a monstrous advantage. i have stasis' center diff now and will have their lsd early next year methinks.

i fully realize the s4 is outclassed but i'm fully determined to beat a rally car whenever i can. i placed 3rd last event behind 2 STis but in front of 1. :0) he coned the bajesus outta the course otherwise he would've beat me too. ;-)

i totally hear you about wheels/tires too and will have that covered shortly too. if you couldn't tell, i know what i have to do to prep the car and i know improved driving skills will net me a lot, but raw power (power/weight ratio...) is what's lacking.

NoahD

15" 205-width track rubber vs. 17" 215-width street rubber yields insane acceleration improvements. 10% lower effective gearing makes a rather large difference.