Greetings folks. The STX 'stang is giving a good fight here locally. Yesterday was the first points event at Lincoln Air Park - Nationals site and with the suspension mods this car is a whole different animal. It ran REALLY well (I thought :P) and the course design was brilliant! I, however was just over 2.5 seconds behind a 1989 BMW 325i that has been to Nationals (driver and co driver placed at the bottom of the pack at Nationals in STX) with unknown prep level. I'm taking the safe assumption and assuming last year they were relatively unprepared and this year they are at a higher level of prep. I should say I was 2.5 seconds behind the #1 guy, but only .7 seconds behind the 2nd place guy.

Here is the suspension set up:
Dunlop Direzza Z1 Sport Star Specs in 245/45/18 on stock rims
Steeda Sport Springs
Steeda HD mount
Tokico D-Specs
Fays2 Watts Linkage
Strano 35mm front bar at full stiff
Strano 25mm rear bar at middle position
UMI Competition Endlinks

Alignment:
-1.6º camber
Neutral Toe
+7.5º Caster

D-Specs were at 2 from full hard in front, and 5 from hard in rear and tire pressure was 31F/32R and judging from the tire roll over scuff marks that is about right for these tires. Kind of low for street tires though I thought? Guess not? Watts link was at the 2nd from bottom hole.

I guess what I'm asking is, aside from seat time which is a very important part of this, where else can 2.5-3seconds be made on a 60 second course?

How big of an impact will going to a 265mm wide wheel on a lightweight 9" wide rim make? The wheels I'm looking at are Enkei's and weigh about 22 lbs each, which should cut down the 28ish lb weight from the stock Bullitts I have on now, tires would be the RS-3 in 265/40/18 vs the 245/45/18 star specs. I don't plan on swapping out my tires just yet but I'm curious if 20mm of width at each corner is going to make that large of a difference?

What about cutting weight out by changing exhaust or seats? I'm not sure how much can be cut weight wise in the STX ruleset from this car, I'm going to guess about 100 lbs between exhaust, seats, wheels/tires and that is probably over estimating it a bit. The other thing I could swap out is the rotors and calipers (I would end up with the Brembo's) which would cut unsprung weight some.

Here are two videos, one on the inside (my fastest run and the one you can't see the course from) and my second fastest run for the day:

http://www.youtube.com/watch?v=WPbGdD7Xs-4

http://www.youtube.com/watch?v=ygcxMVNIC70

Some photos:








The car feels really well balanced and is frighteningly good in transitions. Only on my 2nd run did I have any appreciable understeer and it was driver error and on corner entry. It required extreme use of the brake pedal to get it under control.

Is this a power issue? Drivetrain wise I am bone stock minus a K&N drop in air filter for the stock airbox. So 270 RWHP and about 290 RWHP on bad day? I do have the option of adding a CAI + Tune and doing some exhaust work (high flow cats, shorties, maybe LT's if I can get the high flows within 6" of stock)?

Open to suggestions!

 

I would think the CAI tune would be a great start! The throttle lag from the stock suit alone is enough for at least 1 second (depending on the course layout). Nothing a 93 race tune couldn't fix! As far as the other options, I'm not sure. Cutting weight seems like the obvious fix but is it really worth it in the end? Hopefully someone with more experience can chime in...calling Jazzer and ShaneM!

 

Do you know what tires the BMW was running?

 

Yes CAI/Tune would be a good start, 3.73 gears or 4.10 would be the next upgrade since it's a short course and acceleration out of a turn is critical.

Also, I noticed on that second pic you still have a lot of body roll/lean. Strut tower brace will help stiffen the front end so you can corner more flat. Granted the upgraded suspension when properly tuned will significantly reduce this but a strut tower ties in the top part (often neglected) part of your suspension.

 

I don t off the top of my head, I'm assuming RS3s or RE11.

Gears can't go beyond 3.73s because Ford never put 4.10s or 3.90s in a factory mustang in my generation. I would think the reduction in second gear top speed would negate the added acceleration bonus. I have 3.55s now and 2nd gear tops out at about 65 with the 245/45/18 tires.

Thanks for the suggestions! I appreciate it!

 

I saw at least 2 seconds you left out on course by not picking the appropriate line and being incorrectly set up for the next element. If you'd like an explanation, let me know and I'll write it up in the morning. Hitting the sack now.

 

Yes please do! Keeping in mind on the last run I ran the slalom from the left side and cut half a second off my time which got me to the 63.727. Sadly the video of my 4th run doesn't show anything outside the car...

Anyway, I look forward to the suggestions!

 

Weight reduction is a great idea. I noticed a big improvement from Enkei PF01 and Hankook RS-3 tires over the sumis I was previously running. Better brakes will allow you to set up the suspension so you are ready to exit a curve sooner. A tune can also help. Check out the Vorschlag blog to see what he has done to improve his ride and times. Here is the link:http://www.vorshlag.com/forums/showt...56023#poststop

More than that, I would need to see you run a course, to see where you could improve your line.

 

I've been following the Vorshlag blog and it's been interesting to read but I think they really went the wrong way with their car by adding more power when they knew they were limited to 265 tires on 9" wheels. I'm hoping I can have more success with less power! :P They did have a good deal of info on weight reduction so I will have to re-read the entire thread and see where they pulled weight.

I posted two videos above, I have videos of pretty much all but my first runs last year on my YouTube channel. All of those runs but 2 are from the same perspective on the roof.

Thanks

 

I just ran my second event this last weekend and being a total beginner to this stuff I'd have to agree with jsnyg. People will recommend CAIs and go fast goodies, but I really think it is more about skill at this point. I am NOT saying you are unskilled, but like myself lack the experience. My car has similar mods to yours and I know there is waaayyyy more power and handling there than I need. I am going to be focusing on my driving strategy, setting up turns, reading my tires, etc. It's pretty sobering when a Mini with like 1/3 the HP turns a faster time than you. Like many people I did it backwards. I built my car up before I could even exceed it's potential in stock form. Now I am stuck in a class with beefed up cars and much better drivers than myself.

And about the slalom thing, you always need to enter from the side that will have you exit on the best side to set up your next turn.