After running in Redwood Region AX I noticed a few things about the way my car handles and would like some tips on what I might be able to do to improve things. I noticed the car pushing very hard in the fast corners - I think this is the first AX where I couldnt brake or lift hard enough to get the car's tail to swing so I was just on the gas and front end was working real hard. Checking tire wear my fronts are wearing much faster than my rears.

Here is my cars current setup. 22mm front Weltmiester swaybar, Koni Yellows (front set about 3/4 firm and rear full firm), 140lb rear springs, 5.5 wheels with 205/50/15's I was running 36 psi rear and 35 psi front. I have a stock 1.8 engine with a header so power oversteer is only a dream for me.

Would moving to a higher rate rear spring be a good choice in getting the fronts to hook up better?

I have also noticed my car sits much much higher than most of the faster 914's. How low can you go before you start messing up suspension geometry? How do I get the car lower in the rear?

Over the next year I plan to make this car more of a dedicated AX car. Any reccomendations on improvements you would make for an ultimate AX car? I'm shopping for a hot engine now. I'm considering everything from a hot 1911cc rebuild to turnkey 2300cc engines. I have always liked driving the crap out of under powered cars, but I think I'm ready for something faster now that I'm getting serious.

I'm also going to have the brakes completely rebuilt as my brakes really suck right now. My front rotors are toast and a little warped and catching under hard braking. What is the lastest and greatest brake setup for us 4 lug people who AX? My car has a bigger MC, and stainless steel lines. I will be replacing rotors, pads etc.

You know.. you could have asked me about all this face to face yesterday...

Where is the sway bar set ?

For now pick up Nathan's old 180lb rear welt springs for dirt cheap.

Later:

Have the car corner weighted. TC can do this.


B

With the backs set on full firm... and it is still understeering.. step up on the rear springs.. or set the front full soft and the bar full soft (for testing reasons)

Either tighten the rear or loosen the front.

Here is the key:

If the ass end is stuck...and it plows... loosen it up so it DOES rotate.. or make the front stick better with heavier rear springs. The tire pressure difference you have will make very little difference in how it is handling.


B

In Stockton I completely removed the front bar from the 9146. It was plowing like a pig. I didnt have any stiffer rear springs with me... so I made it rotate by loosening the rear (took stiffness out of the front by removig the 31mm sway bar from the equation.) It also has 23mm torsion bars and 250 rate rear Eibachs. PERFECT setup for the track.. SUCKS on the AutoX course with narrow tires.



B

QUOTE (Brad Roberts @ Apr 17 2005, 12:00 PM)

You know.. you could have asked me about all this face to face yesterday... Where is the sway bar set ? For now pick up Nathan's old 180lb rear welt springs for dirt cheap. Later: Have the car corner weighted. TC can do this. B

Guess I could have asked you yesterday now that you mention it. I really didnt start thinking hard about how the car handled until I was on the road home. Probably need to be more focused on my setup during these events. It just feels like I get better times now at AX events by focusing on my driving and less on the car.

...I didnt even know I had settings on my front bar. So I'm not sure? I'll have to get under the car and check.

If I do something to the rear of the car I want to go with what ever is the best, cost is less of a consideration for me with the suspension. So would Nathans old springs be the best setup?

try the 180's or find some 200's.

both are 'mo better.

Geoff

Hi Grant,

I agree...move up to 180's or 200's. The car will rotate easier and you can then dial the front bar. I don't know if we have ever met but i used to run auto-x's quite a bit the last 2 years and the spring change is really nice for an auto-x. The only thing is if you are running in Bi class the limit is 140lbs. If you are running Bp or don't care, the heavier springs will make the car turn.

Last year Brad changed out my front bar for a 27mm Smart bar and did a caliper rebuild the night before an Auto-x at Alameda. He worked on it all night and didn't sleep (neither did I!). We got to the Auto-x and even at full soft on the bar in front I couldn't get the car to turn.

We were running 350lbs springs in the back and I have several sets of springs in my trailer for the track, so we swapped them out of the car in "13" minutes in between sessions with 375lbs springs. The 25lbs increment made all the difference in the world. I ended up 4th overall doing only 4 runs due to the brake problem. But it was the swap of springs that made a difference.

You're gonna like it

Bill P.

And Grant,

Whatch out for the dedicated track car thing....it gets out of hand...ask me how I know....



Wait till you see the car Brad is building me....it should be entertaining to say the least.

Bill P.

QUOTE (nine14cats @ Apr 17 2005, 04:44 PM)

Hi Grant, I agree...move up to 180's or 200's. The car will rotate easier and you can then dial the front bar. I don't know if we have ever met but i used to run auto-x's quite a bit the last 2 years and the spring change is really nice for an auto-x. The only thing is if you are running in Bi class the limit is 140lbs. If you are running Bp or don't care, the heavier springs will make the car turn. Last year Brad changed out my front bar for a 27mm Smart bar and did a caliper rebuild the night before an Auto-x at Alameda. He worked on it all night and didn't sleep (neither did I!). We got to the Auto-x and even at full soft on the bar in front I couldn't get the car to turn. We were running 350lbs springs in the back and I have several sets of springs in my trailer for the track, so we swapped them out of the car in "13" minutes in between sessions with 375lbs springs. The 25lbs increment made all the difference in the world. I ended up 4th overall doing only 4 runs due to the brake problem. But it was the swap of springs that made a difference. You're gonna like it Bill P.

Thanks for your thoughts about suspension. I think I'm going to go with a little stiffer spring rate.

I remember you from my first AX that was held at Marina. I drove my Boxster then (First and only AX in that car because my wife thought I was abusing it too much! ...she was right) It hasnt been until this year that I really have been able to really focus on driving my 914 more.

I'm likely going to continue on my path to a dedicated AX/track car. I just want a light fast simple car that doesnt get in the way of my driving.

I'm really itching to get a little more power and some fatter wheels and tires under my car as well. I know my driving has improved enough to take advantage of more better stuff.

I think my car is currently Ai class, but I want to run which ever class puts me close to the cars that run TTOD at AX without breaking the bank. Track is just to have fun for now.

OK, My $.02 worth here, from auotoxing a 914 for numerous. years, YOU want a balanced car to not plow(unersteer), no rear end swing, basically if you set into the corner right it and it goes around and out the other side smoothly. Those who trash around the course are really not the fast ones.

Mine was set up by Dwight Mitchell when we were runnin together, really awful to finish second, but against him that we somewhat OK.

What else can I say. I know that I have 140's in the rear and no rear sway bar. larger sized front bars and sway bar( do not remember the sizes, sorry). Run stock fuchs with a variety of tires.

This year if the dates work out will be back with hoosiers, got a deal on them and wil see what happens. Haven't really run much except for a few CRABS over the last few years (was within1 second of Steve N. on really old tires). Now ready to get back into this.

Won't be a the SVR May event as will be in sunny Mexico. I do have other priorities than Porsches.

Mike or as some know chilli.

PS, BTW, will be back as chief steward for the GGR buttonwillow event in June.

I'm running a 22mm AR bar & 21mm Tbars and 225s aren't enuff....I'll sell em' to ya, tho....cheep, too The sale would help me afford some 300s....I'm tired of trying to creep up on this thing

JP,

I actually told Chris Reale to go back to stock torsion bars with his Tarret front bar. I ran that 9146 semi decent with NO bar and 250 rate rears and 23 fronts. Basically loosen the rear. I personally believe you need a softer setup because of your venues. We can get away with 350's in a 9146.. dont try it with a 4cyl. car (for those of you playing along at home..LOL)


Bill was also on Goodyear slicks..


B

Brad:
You may well be right.
The only reason I swapped out the 19mm bar was that I got a hell of a deal on the 22mm and we know the problems with the Welt down link/U-tab problems...... and back then I was still thinkin' DE rather than AX only. The 21 mm Tbars are for our rough course to keep from bottoming the suspension while keeping the car semi low. If the 300 pounders don't make the car neutral I'll go back to work on the front. I've got a set of raised spindle struts to get some travel back.

I've found that I can drive around the push, but I need more practice at it..... but would rather not have to.

Now if I would quit gettin' "ideas"...I could get this sucker done. I got 3-5 lbs outta my engine lid.....but it took all day.
I got nearly 200lbs (semi WAG) out of the car thus far this time around.

Chilli - thanks for the WARNING about buttonwillow.

Ken

just for clarification, my springs are 140's.... i'm moving up to 200's, maybe 225's... with larger Tbars. i feel like i've got too much brake dive right now. got a 22mm welt bar. rear stock bar..

also, the 140's are really "club" springs. they're not mine; i've just been borrowing them. they've been on andy's car, jenny's car, and now mine. i look foward to passing them on to another club member when i'm ready. they've certainly got some history now!

n

What shocks do you have Nathan ? Koni adjustable rears set mid firm will stop the dive (which I personally feel you can use to your advantage with slight brake "taps" to turn in.

Do you have the stock rear prop valve ?? lose it. That dive will go away and the car will stop flat.

Sorry about the 180's Grant... *thought* Nathan told me they where 180's.


B

I put my 200#'s on today.

What are the advantages of having/not having the prop valve? Should I remove mine as well?

KT

QUOTE (grantsfo @ Apr 17 2005, 11:44 AM)

Would moving to a higher rate rear spring be a good choice in getting the fronts to hook up better?

As you have already read, yes it will.

QUOTE

How low  can you go before you start messing up suspension geometry?  How do I get the car lower in the rear?

Conventional wisdom seems to be that you can go until the A-arms and/or the trailing arms are level with the horizon. Then things start to get a bit whacky.

To lower the rear of the car, you change out the springs. Or move the spring perch. (Koni and Bilstien shocks only, I think.)

QUOTE

Over the next year I plan to make this car more of a dedicated AX car.  Any reccomendations on improvements you would make for an ultimate AX car?

RTFR. Read The F***ing Rulebook. Unless you want to be classed with Provasi in the "Orange Crate".

If you're going all-out, I really like the notion of having smooth low-friction bearings at all of the places the suspension moves. Most especially the pivots for the trailing arms and those for the A-arms. (Paging Mike Mueller, Mike Mueller, white courtesy telephone please!)

QUOTE

I'm also going to have the brakes completely rebuilt as my brakes really suck right now.

A full rebuild with good stock parts, and a set of aggressive brake pads. Porterfield "street" compound (RS-4, I think?) or Hawk Blue, or one of the other very aggressive streetable pads. And learn how to not use the brakes. As B says, brakes only slow you down...

QUOTE

I think my car is currently Ai class, but I want to run which ever class puts me close to the cars that run TTOD at AX without breaking the bank.

Umm, nope. I don't think there really is such a class. Not unless you're one of those guys who can drive anything and be blazing fast.

I feel there are three ways to approach this. First, you can pick a class based on the rulebook and build the car to that. Pick your class based on your budget, what kinds of things you like to do with the car, what parts you already have, and so on.

Second, you can decide without looking at any rules that you want "X" modifications and then you'll drive the car in whatever class it lands in. Often, you'll wind up in the same class with people like Provasi or Steve N. or others with much more car than you. (And almost always with much more driver... Or is that just my experience? )

Third, you can set a budget and try to maximize the car's potential within that budget.

Sounds like you're trying to do the third option without specifying a budget.



Next, Trekkor asks:

QUOTE

What are the advantages of having/not having the prop valve? Should I remove mine as well?

Advantages of having the prop valve: You've already got it; no mounting hassles; cheap; locking up the rear wheels before the fronts lock will make the back end of the car try to pass the front end.
Advantages of no prop valve: Simple; no way to trap air like the stocker; cheap; the rear brakes can do more work so you may decrease your stopping distance--or you may lock the rear brakes, depending on all the other parts of the system.
Advantages of having an aftermarket prop valve: Adjustability means you can make the rear brakes do more work but not so much that they lock first. Does not trap air like the stocker. Of course, you might wind up running it fully open--leaving you with a very expensive "T"...

--DD

Trek,

With your 6cyl in the car now.. I would remove it. Most of them are worn to the point where they are almost fully open anyway (yes.. I tested this with a brake pad replacement pressure tester.. it test's the piston pressure when the brakes are applied) Slick device.


B

I see how much time I can scavenge to do it this week.
What will the brakes *feel* like after the tee is in?

KT

grant, your car looks really nice right now. i'd kinda hate to see it become too much of a race car...

i have very little to offer per advice, but adding that race seat and harness is one of the better things i could do for my driving technique -- exposing the problems of my technique, that is. now that i am firmly in my seat, i am able to see how much slop is left in my input to the car. the best way that i can put it is that the seat "isolates" the input, thus letting you focus on it. just by keeping my ass planted, i realized -- especially on sunday, how much better a driver i COULD be.

hoosier's help, too

The car will dive a little less and it will rotate a little better. It will feel flatter under braking.


B

QUOTE (nebreitling @ Apr 18 2005, 02:23 PM)

grant, your car looks really nice right now. i'd kinda hate to see it become too much of a race car... i have very little to offer per advice, but adding that race seat and harness is one of the better things i could do for my driving technique -- exposing the problems of my technique, that is. now that i am firmly in my seat, i am able to see how much slop is left in my input to the car. the best way that i can put it is that the seat "isolates" the input, thus letting you focus on it. just by keeping my ass planted, i realized -- especially on sunday, how much better a driver i COULD be. hoosier's help, too

I bought the car originally because it was so clean. I knew I could drive it for 4-5 years without dumping any money into repairs. That bet paid off. I was able to put 25,000 miles on the car over 4 years with minimal investment and its still running strong. I also knew an average 74 1.8 wouldnt be a real collectors car so it had AX/track car written all over it to me, especially after my wife backed into it and the original paint job exploded into pieces where she hit it.

My plan is to keep it barely street legal, lights, exhaust system etc., but I want something that gives me a chance to go hunting for those real fast times. I'm really not satisfied with being a relatively quick driver in a 1.8 with skinny wheels and tires. I want the challenge of something much faster

okay then. read to rule book, and start pulling off dead weight. got fiberglass? lose as much as the interior as you legally can. get all the sound tar etc. out. get some custom 6.5 or 7" wide wheels and hoosiers. AX alignment/corner balance. you could use some negative camber, for sure. i think that your header already puts you into Ap (not Ai) or Bp, so hit the limit with that class at least. add race seat.

i'm still in progress of doing all the above as time and (gulp) $$ allow.