well, the title pretty much sums it up. i wanna use a gear drive in my current 383 stroker tpi build. whats y'alls thoughts on this? how's the tpi's ecm react to the gear drive? anyone done it?

thanks,
nick

 

The knock sensor isn't going to like the gear drive. They sell a quiet gear drive though. Maybe there won't be any problems with that. ???

 

won't work with the knock sensor. it will take the noise as knocks and the engine won't run right. also a chain is better anyway

 

Ever tried it to back up that statement it wont work with a knock sensor?

 

no, not personally, but it common knowledge thru-out the board, a quick search will show a wealth of information on the subject. also, most reputable aftermarket sales companies show it on the information about the gear drive... "not for use on vehicles with a knock sensor."

 

Really? I'd like to see this common knowledge and wealth of information saying it doesnt work. Probably just a bunch more people who have never tried it, and rehashing past myths.

Plenty of people here are running them with no problem. I only personally know of one person here in the past 10 years that said they had issues. Even one person I know if is running the noisy Pete Jackson version with no problems. I've been using a 'quiet' PJ for 15 years with no problems.

 

im not saying that its going to make your engine run horrible, but the knock sensor can read the extra noise from the gear drive as false knock counts. do you have a scan tool or laptop hooked up to your ecm at all times to see if you are getting knock counts? i know i was getting false knock counts from my engine just by using 6" rods rather than 5.7". and its not something you will notice by just driving your car, it will have to be seen by a scan tool, it may only retard the timing a degreee or two, the point being is it can.

im sure you have ran your gear drive without problems on your knock sensor, every engine is different, it may be the brand of gear drive you purchased, it may be that you put extra teflon on the knock sensor, a lot of things factor in. the choice is yours, but i'd rather have the extra insurance of the ecm possibly reading false knock counts than to have a gear drive.

 

I'm certain you have zero proof to back that up, as does everyone else I've confronted who says a gear drive will set off the knock sensor. They havent tried it, they just state things they have no personal knowledge of.

 

there must be a reason why companies put on the box, "not for use with vehicles equiped with knock sensors." i too am curious whether i can run one on my 383 tpi build aswell, but if the company itself is encouraging me not to use it on my car with a knock sensor than that means there research and product testing has brought them the conclusion that it affects it somehow.

perhaps it only happened acouple times on the cars they tested, but i find it as cheap insurance just to skip it all together and just use a double roller chain.

 

thanks. still not decided, but id still like to run it. i can always pull and replace with a chain if need be. im running a MAP style TPI and I was planning to ditch the computer ignition for an HEI MSD setup with external MSD Coil and 6AL MSD Box, dont know if that affects it at all. The two big reasons why i want a gear drive is 1. reliability and knowing it wont stretch or break and 2. being a young guy, i like noise, alot of noise, and i love that whine it gives you i was planning on an Edelbrock dual idelr noisy gear drive. I've also heard rumors that the extra harmonics is hell on the engine's internals, especially the valvetrain. Any opinions on any of this?

thanks,
nick

 

As far as backing up the data that it messes with knock sensing / ecm tuning, etc I can say this. I'd believe that a gear drive instead of timing chaing would / would mess with a knock sensor. I had a roller rocker hitting the spring retainer, just enough to leave a hit mark on the rocker. Those hits were being recorded as a HUGE amoutn of knock. I'd think that the knock sensor would pick up the additional gear mesh noise and knock and try to adjust. The gear drives I've heard (all Pete Jackson's) have heard like superchargers almost.

 

And gear drives have more resitance than a double roller.

 

the knock sensor reads noise/vibrations. gear drives make more noise/vibration. any extra noise/vibration COULD make the knock sensor read it as false knock counts.

i have plenty of data logs on my laptop showing my false knock counts cause of my 6" rods, because 6" rods make more noise than 5.7" rods. im not trying to get him to not buy a gear drive, just giving him the knowledge that it is a possibility for the the ecm to read false knock counts because of it.

everything else aside, in my opinion a chain is a better design, if you look at the two side by side the gear drive only meshes together about 1/4 of the teeth, and the chain meshes together with half the teeth. you could get 100,000 miles on a timing chain before it stretches enough to put the timing slightly out of time, so i see no reason to get a gear drive unless you want the extra noise.

 

ive always seen "not for use on motors equipped with hydraulic roller lifters"

 

I had a pete jackson (quiet) gear drive in my old 305 tpi and never had a problem.