This came up about a month ago. I had lowered my high side limiter to keep my mph at or below 150 mph. During a time run I hit the high side limiter after the 1,000' mark. Apparently, I need to lower the limiter a little more because I ran 152 mph.

I provided NHRA's rule on the ignition below.

What are your thoughts on this & was I legal or not? What would be the consequences if it was illegal, it was a time run?

2BKING

quote:

quote:

2nd time hit: I ran all out but was on the high side limiter after the 1000'.

Running on the chip is illegal. This is essentially what they referred to as a 'stutter box' decades ago.

Personally I would not want to be on the high side chip that long. Maybe I am wrong but to me it would be hard on the engine, especially the valve train.

Since you have a pro charger, why don't you control it with boost?

Big,

I wasn't on the limiter that long, it was somewhere "after" the 1,000' mark & I don't remember where.

As for controlling my mph, I do that with my left foot & my hold numbers. Out of 300+ passes I've only been 152 mph twice. Once was on the limiter after I lowered it & wanted to see at what mph it engaged or held me to in the mph cones.

Now, the purpose of this thread was the questions I asked in the OP, but I appreciate your concerns.

2BKING

I had a same situation at a nhra bracket finals one year. After talking to the tech inspector who came to see me, I finally convinced him it was just my high side rev limit, not a stutter box. Was bluntly told to either raise the rpm limit or remove it all together. Reason was it was making the car run the same every run. If I didn’t comply he said I would be disqualified if it happened again. That’s nhra for you

quote:

Originally posted by Wooley:
If I didn’t comply he said I would be disqualified if it happened again. That’s nhra for you

It doesn't matter if running into the chip is intentional or not; it is not legal and you need to change something to prevent it from happening in eliminations.

Lenny I understand where he’s coming from. I ended up raising the limit to 7600 rpm from the 6800 rpm that I normally ran. This was a 1/4 mile race after racing all year 1/8 mile. The engine in the car at the time was a stock 2bolt 400 sbc with the stock cast crank. It had eagle h- beam rods and trw pistons. Was balanced externally still. I never thought about the limit until that moment. I was just trying to to keep a cheap engine together.

I didn't need to tell anyone about hitting the high side limiter & didn't realize I did until reviewing the data log. No one heard it including myself.

So, how can anyone or NHRA enforce this? In my class Pro, our track rules don't allow use of a data logger; even though NHRA rules allow it. My ECU is NHRA approved & I can only data log with the data card(s) in. Well, I run without the data card(s) in eliminations.

The way I look at it, I'm not changing anything to keep it from happening in eliminations. Because I'm not on the hide side limiter; my feet control my rev limit(s).

Some may not like my reply & that's fine. I'm just putting out what can be done if someone wishes to.

2BKING

quote:

Originally posted by B KING:
I didn't need to tell anyone about hitting the high side limiter & didn't realize I did until reviewing the data log. No one heard it including myself.

So, how can anyone or NHRA enforce this? In my class Pro, our track rules don't allow use of a data logger; even though NHRA rules allow it. My ECU is NHRA approved & I can only data log with the data card(s) in. Well, I run without the data card(s) in eliminations.

The way I look at it, I'm not changing anything to keep it from happening in eliminations. Because I'm not on the hide side limiter; my feet control my rev limit(s).

Some may not like my reply & that's fine. I'm just putting out what can be done if someone wishes to.

2BKING

Then why ask for an opinion, when you dont want an opinion...

Hitting the high side chip is not the same as using a stutter box nor is it illegal.

It says it right in the rule. "Time based ignition interruption devices (stutter boxes) prohibited" It also states that "starting line and/or high side rev limiter permitted."

Now, if you have the "high side" on a timer, you would be illegal.

Just my .02, take it for what it's worth.

quote:

Originally posted by Jonesz:
Then why ask for an opinion, when you dont want an opinion...

Jonesz,

Back to the original post, what's your opinion or as I put it "thoughts"? I don't have to agree with it, the same as you don't have to agree with mine.

"What are your thoughts on this & was I legal or not? What would be the consequences if it was illegal, it was a time run?"

2BKING

sand bag more and the problem will take care of itself

quote:

Originally posted by seabass:
sand bag more and the problem will take care of itself

I don't see it as a problem for me. Since having this abundance of mph, I think I've managed it pretty well. As mentioned before 300+ runs with only one time being on the limiter while testing the waters in a time run. I consistently kill a minimum of 20+ mph with my right foot & when needing more, the back-up is the left foot.

IMO, it's more of a problem for others. Including the DRR member who brought it up 1st in another thread & other members in this thread. IMO again, I think it's more of a sanctioning body issue to address or maybe not.

2BKING

The first time a competitor hears it , you will hear it. Think I would do it with weight, as much as you can then use the timing curve. It’s possible to run a throttle stop internally with EFI?

quote:

Originally posted by TomR:
Hitting the high side chip is not the same as using a stutter box nor is it illegal.

It says it right in the rule. "Time based ignition interruption devices (stutter boxes) prohibited" It also states that "starting line and/or high side rev limiter permitted."

Now, if you have the "high side" on a timer, you would be illegal.

Just my .02, take it for what it's worth.

Here is the full rule:

Timed ignition-interruption devices (stutter boxes) prohibited.
Starting-line and/or “high-side” rev limiters permitted. Two-steps, rev limiters, or any other rpm-limiting devices, legal unto
themselves but altered or installed so as to function as a down-track rpm controller, prohibited.

Everyone knows what a high-side limiter is intended for. If it is set in a manner to limit your RPM downtrack on a run without any breakage or unusual circumstance, it is not legal.

quote:

Originally posted by Lenny5160:
Here is the full rule:

Timed ignition-interruption devices (stutter boxes) prohibited.
Starting-line and/or “high-side” rev limiters permitted. Two-steps, rev limiters, or any other rpm-limiting devices, legal unto
themselves but altered or installed so as to function as a down-track rpm controller, prohibited.

Everyone knows what a high-side limiter is intended for. If it is set in a manner to limit your RPM downtrack on a run without any breakage or unusual circumstance, it is not legal.

I agree & I did post the full rule in the 1st post.

Technology has come a long way on how you can limit your RPMs both on the low side (2-step) & the high side. Fuel injection allows you to have more control on how to do it. There's a Fuel Only, Spark Only, Fuel & Spark, Soft & Spark High only. Plus, you can go into the fuel and/or timing maps to help with the areas during the rpm limiting. Ask me how I know, my ProCharged combo was not happy on the RPM limiter. I had to learn to how tune it while on the limiter.

So, I'll go back to what Barry stated. "The first time a competitor hears it, you will hear it." As long as no one hears it, you're good to go! I'm not using the high side illegally other than for the one test run, but I'm reasonably sure others are.

I know many people hear my high side limiter when ripping the throttle on my ProCharged combo!

2BKING

I have a high side limiter in two devices, the Grid and as a back up in the MSD ignition box (a chip). I programed it in these devices for the sole purpose of protecting the engine, the car, from a crash, (been there done that) and my skinny, 84 year old butt.

Under no circumstance, (Track Official, NHRA Official, Ex-Wife or P.O. Big Bubba) am I ever going to delete or override these limiters.

Especially the Ex -Wife.

Bob

Lenny is spot on here.

ep

quote:

Originally posted by B KING:
I agree & I did post the full rule in the 1st post.

I do most of my DRR-ing on my work computer, where photo sharing sites are blocked. That's on me.

It's pretty clear in the rules, using a high side limiter to control et/speed is prohibited and can result in a DQ. If you want to slow the car down, pull boost, pull timing.....don't limit rpm. Hitting the high side limiter can damage the engine, and on boosted or power adder stuff can possibly backfire the engine....and that isn't good. Why not use a pedal stop to prevent WOT? Not illegal since it's a mechanical device that doesn't move. Just a thought. But I wouldn't be using the high side limiter on my stuff regardless. I set it at the max rpm I want my engine to see if something happens to protect it. Pulling timing is much more effective and safer. But thats just my opinion

quote:

Originally posted by B KING:
I don't see it as a problem for me. Since having this abundance of mph, I think I've managed it pretty well. As mentioned before 300+ runs with only one time being on the limiter while testing the waters in a time run. I consistently kill a minimum of 20+ mph with my right foot & when needing more, the back-up is the left foot.

Thanks everyone for your opinions, thoughts & especially your concerns; apparently some think I'm always on the high side limiter. I could do it again & not worry about it damaging anything, it was that smooth that I didn't notice it.

I'm putting a fork in it on the high side & need to do more work on the low side!

2BKING