In my previous post I asked about the REV Limiter. All questions have been answered except the actual safe RPM limit on the DS. The stock rev limiter is 7,700. Team Pami has indicated that a safe limit for a stock engine (w/Pipe & Jetting) is 8,500 RPM. However, my brother was told by Ron Woods that the engine can reach up to 10,000 RPM without causing any damages. Please share all knowledge on this subject! I would like to make sure that I do not cause any damage to my engine.

Thanks,

Joseph

00 DS 650
Custom X Muffler
Alba Racing Kit
K & N Filer
Nurf Bars
6 Pack Rack
PRM Complete Undercarrige Protection

 

I have the graydon-proline rev box for a while and no problems here.It rev's to 9300rpm's before it kicks in.Graydon told that the motor could handle it easy.

 

Ron Woods told you correctly, the can spin up to 10,000 and survive. The problem is that spinning that high is well past your power and does nothing but stress the motor unnecessarily. Another point is that as a motor gets more hours on it, the valve springs start to lose tention. When this happens, the motor is likely to start floating valves and damaging the motor. With peak power being produced at 7200RPM, and a sharp decline in power after that, why would you want to spin your motor to 10,000 or even 9,300, from that RPM, even after you shift, your past your peak power.

 

The next logical question that comes to mind would be: What is necessary to use some of those higher RPMs? How about just a pipe and other basic mods, would these warrant the use of a reworked rev box, or is the box only really effective on 'built' engines. (Wether a person goes with one builder or another.)

 

A rev box was going to be my next investment, cause it fells like it still pulls up to hitting the limiter. If it isn't gonna make any more power than that money could go into better things. Later

 

The stock CDI box has retarded timing in the upper RPMs, which is part of the reason the power drops off as quick as it does above 7500 RPM. The woods rev box advances the timing 4 degrees at the low RPMs and eliminates the retard in the upper RPMs.

 

To safely use the higher RPM, you would have to[at the very least]install stronger valve springs. This would still not help the power at these levels. To make power at a higher peak you would [again,at the very least] have to change to camshafts designed to produce power in that range. At that point you would want to look into several other mods as well to capitalize on the higher RPM as well as protect your investment. The higher RPM you turn, the more you will want to reduce your rotating mass in order to prevent dammage.

 

Sometimes when I race I have lost close races because I have hit the rev limiter while shifting in low gears. I uderstand that I should be cautious and shift early but sometimes you make mistakes. Everytime I hit the rev limiter in low gears in close races I usually loose. These close races are bike that are fairly matched in performance with my bike. Such as other DS's, Bachees and Raptors (Well with Raptors it's only when rolling out).

I could only assume at this time that a box that would increase the rev limit would prevent this. Also, the bike feels like it could go just a bit more faster without hitting such a conservative limit. Unfortunateely, I cannot say that I am an expert on the subject but I do feel (performance wise) that the bike would go faster at a higher RPM. I feel good with the REV limiter by team PAMI that sets a limit of 8,500. I would say that this is conservative and appropiate for a stock DS with a Pipe and filter. Please share comments.

Thanks,

Joseph

00 DS 650
Custom X Muffler
Alba Racing Kit
K & N Filter
Nurf Bars
6 Pack Rack
PRM Full Undercarrige Protection

 

In a perfect race, you would want to shift at the exact RPM that places the peak HP in the middle of the next gears range so that your motor is always operating as close to peak as possible. With the stock box, that shift point is almost at the limiter. A pipe and jetting will not change were the power is made, only increase how much is made. A new box will change the point were power is made[slightly] but allow for late shifting without cutting back the power more than motor does itself. You will still see a loss of power, the higher you rev past peak, but with an aftermarket box the loss will not be caused by the electronics or be as severe.