How Do It Do That? (Smart vs Kewl)

Not necessarily. The engine runs better at higher (but still reasonable) RPMs. In my experience the lower mileage at speed is due to the engine struggling to defeat wind resistance.

The original equipment ACVW has a built-in rev-limiter. It's call the Stock Carburator.

Rev-limiting is for hot engines and fools like me who accidentally run up past 8,500RPM.

So the manufacturer's suggestion about getting an ignition system with rev limiting provides no useful function other than helping the dealer score a few more bucks. No "better mileage, throttle response, performance and overall driveability" for the Wonderbus. Gotta love these guys -- I told him this was a daily driver.

Only function of the rev-limiter is to limit the revolutions of the = engine to some value. CDI will cut out the ignition if revs go over the limit. Only application and benefit of a rev-limiter is that it will prevent you from over-revving your engine. Maybe useful, if you do racing with your car and use revs near the max of the engine all the time.

For a daily driver - no use.

I would be more interested in a system that detected knock and retarded the ignition accordingly. Yeah, there is one, but it is way too spendy right now.

I like to set the limiter where I want to shift, then just hold the pedal to the floor and at the same time push the shifter towards the next gear. Ignition stutters, shifter goes in, happy days, no clutch. :) What? You don't drive like that daily?

I used to. Works great unless you accidently miss a gear or hit the wrong gear. Slam shifting from 3rd to 1st isn't all that much fun. But I've never tried it in a bug.

Randy

I can only relay my personal experience with a setup similar to what you are looking at, for an otherwise stock 1600 dp T1 engine(code AD). I have the standard Tiger "something" CDI from Universal Industries hooked up to a Pertonix 1 point replacement module installed in the stock SVDA dizzy.

Pros:

1. Easier starts, less than a full revolution when there's gas in the carb.
2. Slightly stronger top end, where the stock Kettering system normaly shows it's weakness.
3. Lower emissions?? Less consumption?? (Have I ever masured either? No..)

Con:

1. More likely to leave you stranded if a failure should occure, stock Kettering can often be improvised.

Then the question remains: Do I think it was worth it? Yes, absolutely!

J.

LOL.

I'm not interested in more speed, was just wondering what physical explanation could cause the rev limiter in a fancy-pants ignition system to provide "better performance, mileage, throttle response, starting and over all driveability" (per the manufacturer) to the Wonderbus. And of course there is no such physical mechanism. There is, however, a marketing mechanism.

I forgott to mention some of the T2 cars i have driven came with a stock rev limiter, although crude, the rev limiting rotor, had a weight which shorted out between the dizzy posts being very efficient.... Never could figure out the reasoning behind this device myself. (Drove a belt wagon in the military which had the same crude device, well known for setting their paper air filter on fire from miss/backfires if you pushed them to hard).

J.

On Wed, 14 Apr 2004 16:28:55 -0700, "Mike Rocket J. Squirrel Elliott" ran around screaming and yelling:

that is the description of what the actual CDI is to do for your vehicle...the rev limiter *simply* keeps you from over-reving the engine.(on acceleration only...mechanical over-reving such as downshifting too early will *NOT* be affected by any rev limiter) JT

Yep, yep, yep. So to re-cap from my original post: I wrote a Prominent Manufacturer of CDI systems and he suggested two models. Their basic, AND for a mere $70 more, the one with rev-limit. Of the rev-limiter, he said that ". . . this will help increase fuel burn in the cylinder and by doing this it will help performance, mileage, throttle response, starting and over all driveability. The amount will very from application to application but it will help."

So yeah -- my post was not about advantages of CDI systems, but whether anyone could help me understand how a rev-limiter could offer all those /wonderful/ benefits on my bus. Knowing that it can't, the manufacturer's last sentence makes sense. The amount will vary from application to application. In this case it varies all the way down to zero.

On Wed, 14 Apr 2004 18:36:21 -0700, "Mike Rocket J. Squirrel Elliott" ran around screaming and yelling:

either he was reading off a cue card about the CDI itself, or you misunderstood his responce...(not meant in a bad way)....the rev limiter is as it sounds...limits revs...only benefit is the "safety" factor of NOT over reving(which can open a whole different can of worms that would make any improvements from a CDI a low priority) JT

He's just try "Sir,

"If you do not want a rev-limiter then use the [simple model]. If you want a rev-limiter then use the [fancier model]. This will help increase fuel burn in the cylinder and by doing this it will help performance, mileage, throttle response, starting and over all driveability. The amount will very from application to application but it will help."

On Wed, 14 Apr 2004 19:43:52 -0700, "Mike Rocket J. Squirrel Elliott" ran around screaming and yelling:

maybe its me, but that does not sound like he is refering to the actual rev limiter providing these results...but *MAYBE* it is because i know the difference?....it seems he was listing the features of the two models then telling what the cdi does...but you could be right...he may have been trying to sell you the more expensive on...wouldnt' be the first time someone did that... JT

I have a few of these rev limiter rotors. They made them in different "cut out" rpms. I think I saw them for sale somewhere, maybe ac.net? The ones used in buses cut out at 4700rpm or so.

Jan

The benefits he mentions are descriptive of BOTH models, forget the rev limiter. The benefits he talks about have to do with the CDI technology. The rev limiter is an optional bonus.

Jan

Then I was mis-reading his e-mail. I assumed that "This", in "This will help ..." was referring to the fancier model. I'll suggest to him that he replace the word with "Both of these models ..."