8F Park rev limiter

[Mars]

I plan on trying something a little different out here...

It might not even be of any benefit, so I'd like to hear some ideas / opinions on this.

The plan :

Use the in park rev limiter built into the 8F code for track use to launch a manual car / WOT shift.

Objective here is consistency, NOT all out speed. Also, make it easier to cut better RT's.

Basically pull up to the line, and be able to hold it at WOT boucing off the low rev limter, which would be activated when the clutch pedal's on the floor... once it's released, bam full revs.

Time comes to shift, hold the pedal on the floor, the clutch activates the low rev limiter, bang the next gear. ect.

Thoughts?? I think it would be pretty easy to do, I'm just not 100% sure if it would help or not. Going for MAX consistency, and this is using 235/60-14 MH racemaster DOT slicks.

[Joseph Upson]

I thought about that some time ago as well as using it as an anti theft and abuse mechanism. I'm not sure if you will have the consistency you are looking for with it.

[SappySE107]

I thought about that a while back as well but never went through the DF code to find any delays associated with the p/n to gear change. I don't believe it will work quite like you want by just wiring it in, and I am not sure if that is a good idea to have it limit during the shift time. Without actually testing it, you are taking a risk. I would certainly like to know:P

[Mars]

Maybe I will experiment with it a little.

Would be just as easy to get an RPM switch and wire it with a relay to directly cut power to the ign. module for a split second.

That would sound rough as hell, with backfires, ect. I'm sure you've all heard the Hondas that have this kind of setup at the track...

It would be nice to have a factory style limiter, that wouldn't sound soo choppy, "soft' limiter.

Hell, could alse wire it with a relay to work of the VSS, when it's below 2 MPH, cut the RPM. ect.

[Mars]

Repost from V6Z24, but it's some good info, so I'll re-post it here in my old thread. This works, and I've used it about 70 times this year. It was set at 3000 RPM and using 235/60-14 MH DOT sports, getting 1.94 - 1.99 short times all day long. I'll try 3500 - 4000 next year.

WOT shift does not work however, this is launch control only.

------------------

I found out this thing has a built in 2 step rev limiter for those of us using a 5 gear trans.

All I did was ground hook up pin D16 on my ECM (it's a or/bk wire) to a grounded switch. When the computer sees ground on D16, the limiter is active. On a manual computer/harness, you may have to pin the connector on D16, cause I don't think this wire is used on a 5 speed. I usually pull up, do my burnout, then activate the switch, make the run and turn the swtich back off when I am in the return lane.

My car was an auto, I did the 5 speed swap, hence the reason why I have the wire... Anyways,

Just ground it out so the computer sees a ground and is "fooled" into thinking your car is in Park/Neutral.

Now, for the software part :

1. Set your P/N fuel shutoff to whatver you want, I will most likey try around 4500 RPM with the DOT slicks at the track. Stock here is 3000 RPM.

2. Set your P/N fuel restore 1 rpm lower than the number you chose above.

3. Goto that launch mode constants and put in "01" Hex at adress "647" This constant is called "IF HI MPH, IGNORE P/N SWITCH". Get this value close to zero (i used 01) and once the computer picks up any clue that the car's moving, it ignores the P/N switch !



Vids 2 step in action :

http://ca.youtube.com/watch?v=YxwGXvuHoto (towards the end, 1:35)

(listen close at 00:16)

http://s290.photobucket.com/albums/ll254/rustyzj/North%20Shore%20Challenge%202008/?action=view&current=NSC08040.flv

http://s37.photobucket.com/albums/e71/ckarppi/?action=view&current=dura_cav.flv

All in all, very happy this works and I've cut my R/T's down a LOT !

[Guest]

Holy shit SWEET RT, on that last run shown at TMP!!!!.

.500 pro tree?

The announcer they use at TMP is the WORST! Always refering to cars by wrong name plate, wrong engine, wrong anything, especially if it's an import, they are all Honda's to him, I guess he at least gets my Datsun right by brand, but that's about it. The GF has informed me after my runs.
He should also KNOW that you can deep stage on a pro tree. The only restriction is if the organization will allow deep for the class. Usually the window has to be marked "DEEP" as well, so that the starter knows that's what you do.

As far as the way the prk/nuet limiter has been working, I'm kinda surprised with the consistancy.

I'm not sure how much of a variation there is in your RPMs while on the limiter, but most other cars, including my Malibu seem to push through by about 300 RPM.
My biggest concern is when you actually launch, if it's in a fuel cut mode (limiter active, before fuel is restored), there could be a bog out of the hole, that might effect at least part of first gear.

Seems to work for you, I prefer the sound of spark limiter though, and is about the only reason I plan on running a DIS-4, is for that two stage built in limiter.

Hmm, I think I'll experiment a bit with this on my test bench and $59. Maybe I can use this for the time being, or add a 3rd limiter?

[Mars]

Perfect light was on a .500 Sportsman tree. I am getting darn good (practice) at the .500 sportsman tree. I double enterd reg. braket and S/warz.

.400 Pro tree, well...

the way I see it, my human R/T is .250 and my rollout when both bulbs are on is around .250 - .290. So a perfect light here, is well, not possible... They didn't let anyone go deep in my class. (12.50 index Street Warz) My best here was back to back .11X's. Still OK, but a tenth is a car lenth... so, well, I finished 3rd which I was suprised at cause it was my first time on the .400.

Announcer said my car was an 87.

The switch works perfect, the RPM variation gets worse pending how much throttle is given. I don't care soo much about if I am high or low 3-4-500 RPM, i just care that I can dump the clutch when I need to to cut a good light, I can dial in a little non-ambitious and make up for the rest with the 3400.

I'd rock a DIS 4 if I could find one. How much they going for these days ?

[Guest]

I thought they had come down, but they haven't. Current list is just over $1000 CDN. I know they can be bought for less, that's just list price.