torque converter question

[John_D.]

Will a higher stall torque converter help or hurt in autocross?

I have been thinking about one for drag racing. But since everyone says they can break their tires loose so much more easily, I'm thinking it might be bad for autocross...

Any thoughts?

Or even better, any experiences? [img]smile.gif[/img]

[zlexiss]

The thing to remember in Autocross is smooth transitions. If you're cornering hard and feel you can add a bit more speed, ease into the gas instead of punching it, and you won't break the tires loose from the sudden change in force.

That said, the converter sounds like a mixed blessing for autocross. I'm most worried about you breaking loose as the car shifts (with a M5, I typically leave it in 2nd gear the whole time). If you want something that will help both at the strip and track, I'd suggest some more suspension work than 1LE sway bar you have now. Maybe some nice shocks to both control the body in corners and help out at the tree.

-Jeff

[John_D.]

That's what I'm thinking, is with a smooth application of throttle I may still be ok... One guy on an autocross board suggested keeping it at 2200-2400 rpm stall, but I'm looking at more like 3000-3200.

The 1LE bars and poly links keep the car a lot flatter, that's for sure. [img]smile.gif[/img]

Tire lateral adhesion, and hard braking coming up on 180's seem to be my weak points with the car.

So my next two car mods are:
- 18" wheels with lower profile tires, keeping the same overall diameter (actually just a tiny bit smaller overall diameter) with Goodyear F1 GS-D3 tires.
- Eradispeed+ front rotors with EBC green pads.

The converter has been on my mind for drag racing for a while, but was going to abandon that if it would kill me in autocross. But I've got some V8's in my local car club I need to "surprise" at the strip, so the converter is probably going to stay on the list. :D I'm nipping at their heels now as it is, with the 120 nitrous shot. (too bad I can't use the nitrous at autocross!) I think a converter would put me on over the edge.

[zlexiss]

Man, last autocross there wasn't enough straight pavement to even think about a shot - first turn was about 20 feet out of the gate, and never stopped..

Do you think your brakes are heating up that much on the autocross course, or would grippier pads like the Hawks and the stock rotors do the job with a lot less expense? You may want to look at stainless brake lines and a complete fluid flush to take some "give" out of the system before you go to new rotors.

[John_D.]

The rotors have just bugged me since I've had the car... warping...

I haven't had an overheating problem with the brakes yet. I haven't been pushing the braking to the limit yet either.

I have had it go into ABS mode on dry pavement twice in emergency situations on the street, usually it only pulses once or twice since I'm right on the threshold with it. I would like to bump the grip up some more to match the upgraded tires, and to avoid the associated heat that is going to come with that.

This last autocross I ran was a blast. There was an access road alongside the parking lot. The course started at one end of the access road, did a couple of veers and a 3 cone slalom, then a 180 at the end of the road, and then halfway back down before diving into the middle of the parking lot for the rest of the course.

The road portion was nearly a 1/4 mile!! I was not able to brake hard enough or late enough for the 180. There was an all-out SM 'vette there hauling some serious @ss on the road portion of the course. That's what made me think of the nitrous...

The new rotors will look cool. [img]smile.gif[/img]

Plus they are guaranteed not to warp! These stock ones drive me crazy.

I'm thinking about braided stainless lines at some point in the process. Just taking it one step at a time (sort of).

And concentrating on just working on "seat time" too...

[Phoenix]

Having a torque converter for autocrossing will help a lot. What you need to do is find one that will keep your car in it's power band, this is usually in second gear as well.

[jmorgan]

get a lower str like maybe a 2.0 str with a 3200 stall will keep the rpms up and with a 2.0 str your effencicy willl be there too and you shouldnt have killer killer tq to break the tires lose to much

[ April 24, 2003: Message edited by: Jason Morgan ]</p>

[Active]

Your brakes really don't build much heat on an auto-x course. The speeds aren't that high and you aren't on them long.

However that doesn't mean a few mild upgrades won't help. Hawk HPS pads a very good auto-x/street pad. They have a good cold bite and are more resistant to fade than stock pads. Also flushing your brake fluid can help with pedal feel. Motul makes a good street fluid. I use ATE super blue, but if used on the street requires you to flush the system more often. Depending on class you could also slap on a set of SS brake lines. While they don't do much for decreased braking performance they can provide a much better pedal feel.

Talk to www.cobaltfriction.com They are the best brake company I have dealt with and have unbelieable customer service. Just give them a call and tell them your application. They can give you plenty of advice.

[John_D.]

Thanks for the brake info Brock!

So, what's the scoop on the EBC Greenstuff pads? The specs on them sound great, yet I don't hear of anyone running them?

They are supposed to dust less than stock, have a higher coefficient of friction than stock, and don't have to be heated up first to reach their optimum friction. They don't resist fade as much as an all out race pad, but like you said, in autocross the heat buildup is not that significant.

[Active]

Compared to the other pads out there the EBC is considered junk. I've heard nothing but bad reviews from them. I however have never run them personally, but the guys I've heard it from are experienced road racers and know their stuff.

Like I said www.cobaltfriction.com and ask for Andy.

[Wicked 3800 V6]

Man Brock, had doubts about you. Very glad to hear you're chiming in over here on my turf. [img]smile.gif[/img]
And John, I hope you're not considering spraying on an AutoX course. [img]graemlins/thumbsdown.gif[/img]
-Rob

[zlexiss]

True that. From the SCCA 2003 rules supplement:

Nitrous Systems: - Any nitrous tank or bottle must be detached and left at home. No nitrous tanks or bottles are allowed at event site whether connected to the vehicle engine or not.

Safety first..

-Jeff

<blockquote>quote:</font><hr>Originally posted by Wicked 3800 V6:
Man Brock, had doubts about you. Very glad to hear you're chiming in over here on my turf. [img]smile.gif[/img]
And John, I hope you're not considering spraying on an AutoX course. [img]graemlins/thumbsdown.gif[/img]
-Rob<hr></blockquote>

[John_D.]

Brock,
Thanks for the feedback on the pads, and the recommendation for a good source of pads. Based on the specs of the greenstuff pads, I would expect road racers not to like them. They aren't designed to resist fade. Just to grip better initially. I may still try them for autox and street, in that case. We'll have one other opinion that way... [img]smile.gif[/img]
I'm the rebel around here about doing things the "established" way...
I know one thing, if it rains Sunday for our next autocross here, these new tires I have are going to kick some serious @ss. They stick in the rain unlike anything I've ever seen before.


Rob,
Nope, not seriously considering. Well, maybe, just on the one long section two weeks ago... :D


Zlexiss,
Thanks for the supplement info. I had not seen that before. Just the part in the rules where it says the line has to be disconnected. I will leave the bottle behind anyway, just to eliminate the weight.


Well, we sure expanded the orginal topic of this thread huh!!! [img]smile.gif[/img]

That's ok, I'm glad to see some discussion over here in this forum! Now that I've gotten involved in autocrossing.

[Roy]

nitrous is not allowed on a road course at all.

as for converters and autocrossing....ive done it. the track i raced at was Road america, so there were a lot of straights. i suggest if you plan to run a converter on a road course that you run 2 trans coolers. my trans got so hot that it started spilling out of the overflow tube. i autotappd it once when i got off the track and it was 250 degrees :eek: i started only doing 2-3 laps instead of the whole session then. as you know, heat kills trannies, and your tranny will not last as long if you road race with a converter. id get a really small one if you plan on doing this often. i never spun out coming out of the turns fwiw. i had the wheels spin maybe twice, but im pushing a lot more power and a pretty high stall.

[Roy]

also, i suggest running brake cooling ducts if you run. they will reduce brake fade GREATLY. pretty easy to make with some tubing and stuff at home depot.