TheSamba.com Forums
 
  View original topic: Underdrive pulley on a Bostig
buildyourown Wed May 25, 2016 10:11 pm

Anybody try one yet. Here is what I'm referring to: http://www.steedafocus.com/steeda-focus-underdrive-pulleys-00-04-584-1-0010/

I bought one last year and just got around to installing it and now I'm having doubts.
I'm well aware of the issues and the downsides for most users. The Zetec in the Vanagon is a unique install. It runs at much higher rpm than the stock focus install. My main motivation was to quite things down. I surmised that running the PS pump at lower rpm would be quiter.

My issue is that the install requires you to trim the dust lip off the timing belt cover. This leaves the timing belt exposed. I'm hesitant to proceed.

jimf909 Wed May 25, 2016 11:29 pm

Where's the all-ears emoticon?

MarkWard Thu May 26, 2016 12:15 pm

You need to believe that when Ford came up with their pulley ratios, they would have calculate the size based on running the engine at redline all day long. I am sure you are not doing that. Spinning a pump too fast can lead to cavitation which is never good. Running an alternator too slow gives a poorer charging rate.

I'd say, if you need to trim the timing belt cover, it is not worth it. If this was a race engine that saw only constant high rpms then maybe, but you will often spend time in heavy traffic and idling at lights.

P.S. I did not even click on the link, but am familiar with changing pulley ratios.

The 87 Audi 5000 had a charging problem with all loads active. The solution from Audi was a smaller alternator pulley to speed it up across the rpm range. You'd be doing the opposite.

buildyourown Thu May 26, 2016 12:21 pm

MarkWard wrote: You need to believe that when Ford came up with their pulley ratios, they would have calculate the size based on running the engine at redline all day long. .

I don't believe that. Nobody would put an engine in a production car and think it will get run at 6000rpm consistently. A stock focus barely ever goes over 4k if it has an auto and is driven normally.
I'm attempting to get the pump rpms back to what the engineers designed around.

Terry Kay Thu May 26, 2016 12:46 pm

<<< they would have calculate the size based on running the engine at redline all day long. .[/quote]

I don't believe that. Nobody would put an engine in a production car and think it will get run at 6000rpm consistently. >>>

Believe it.
The Zetec powerplant has been flogged all over the world in racing applications for eons, way prior to being introduced into the Ford Focus.
The Focus platform using the Zetec is very current, compared to how long the world Zetec has been available.

<<A stock focus barely ever goes over 4k if it has an auto and is driven normally. >>

And where did this dramatic information phenomina generate from?
Got some printed out data sheets showing this average rpm of a Zetec engine to back this up?

With or without a turbo?
The boost probably doesn't start spooling up till 6 grand.

Depends on who's driving it in what.
In your condestoga wagon, probably not regardless of the trans.

If it's in some 18 year olds hot rod, don't be placing a wager on that.

MarkWard Thu May 26, 2016 1:34 pm

buildyourown wrote: MarkWard wrote: You need to believe that when Ford came up with their pulley ratios, they would have calculate the size based on running the engine at redline all day long. .

I don't believe that. Nobody would put an engine in a production car and think it will get run at 6000rpm consistently. A stock focus barely ever goes over 4k if it has an auto and is driven normally.
I'm attempting to get the pump rpms back to what the engineers designed around.

Good argument. I have changed my mind. I think you should cut a hole in your timing cover, put your under drive pulley on and report back how wonderful it is now that your power steering pump and water pump are spinning slower and how awesome your charging system functions with the alternator turning slower.

I find it interesting when someone asks a question, receives an answer, and then attempts to find fault in the answer. If you know better, why ask in the first place? When I hear the word, cut, the word "Hack" comes to mind. By all means hack away.

MsTaboo Thu May 26, 2016 1:43 pm

buildyourown wrote: MarkWard wrote: You need to believe that when Ford came up with their pulley ratios, they would have calculate the size based on running the engine at redline all day long. .

I don't believe that. Nobody would put an engine in a production car and think it will get run at 6000rpm consistently. A stock focus barely ever goes over 4k if it has an auto and is driven normally.
I'm attempting to get the pump rpms back to what the engineers designed around.

I've been running a Zetec for years. Very rarely ever run at 6000 rpm, maybe when passing or pulling a steep hill in third, but only for very short periods.
Most of the time it's in the 3500-4500 range and only in the upper 5000s when passing or pulling onto highways.
Also, never had any problems with noise from the p/s pump. I just don't see the need for this; would rather put money elsewhere.

Robw_z Thu May 26, 2016 2:05 pm

The argument isn't about the motor so much as the transmission. Most factory zetecs were mated with transmissions that didn't demand as much RPM from them as the Vanagon does at the same speeds.

The argument in favor of using under drive pulleys makes sense to me, especially with an automatic that does mostly highway driving.

He'll be driving next to a Ford Focus on the highway, and their alternators will be turning at the same speed, just not the motors.

-Rob

buildyourown Thu May 26, 2016 9:44 pm

Woah, this isn't an argument.
People are allowed to ask questions, and then explain why they think the answer isn't fitting of the situation. Its not even a debate. Its clarifying the question. Its a conversation. Thinking out of the box is how we keep these things alive. Some ideas work out, and some suck. Thats how we improve.
I'm gonna source some spare covers and try my pulleys out. Maybe it will run a lot better. Just thought I might not be the first. I guess I am.

And frankly, certain users why may have heard of a Zetec and dont have any experience with this exact engine, can just quietly move along.

jimf909 Thu May 26, 2016 10:10 pm

buildyourown wrote: I surmised that running the PS pump at lower rpm would be quiter.



I'm definitely not as experienced in Bostig as you but I have not guessed the PS pump as a source of noise. I've assumed the O nly objectionable noise (between 3200 and 3900 rpm) was intake and/or exhaust. Outside of that range it's pretty darn quiet (focus air box on drivers side w/ resonator).

FWIW.

insyncro Fri May 27, 2016 7:49 am

I have run an underdrive pulley on a few Subarus in vans, but havent had the chance to do so with the Zetec, YET :!:

In all honesty, I would send Jim at Bostig a message asking his feelings on the subject.

Many variables at play here.

I have an EG33 with an under pulley and lightened flywheel, along with many other hop ups.
I did this for fun, because I can.
Man, it will spin fast and quick.

thasty07 Fri May 27, 2016 7:59 am

I say try it, cutting edge innovation doesnt happen from the arm chair :D

thatvwbusguy Fri May 27, 2016 8:01 am

Are you running factory power steering lines with the restrictor, or replacement lines?

My old '87 Wolfsburg had rotten power steering lines when I bought it. I quieted the pump down completely by pulling it off and replacing it with the Bostig idler pulley :wink: I actually prefer the feel of manual steering on the road, but that is clearly a personal choice.

insyncro Fri May 27, 2016 8:10 am

I have also pulled the pump for the Bostig pulley on one conversion.
The feel of the road for sure.
As long as your alignment is in check, parallel parking is a breeze.

And yes, Jay is right on, you need the restrictor or the pump will howl.

buildyourown Fri May 27, 2016 11:34 am

thatvwbusguy wrote: Are you running factory power steering lines with the restrictor, or replacement lines?

.

I did blow a line and had to make a replacement. I used the banjo fitting from the stock line so not sure if that's were the restrictor lives.
I recall you mentioning the restrictor in another post. I tried to make my own ( small orifice in a SS disc). It made the line leak like crazy so I removed it immediately.

insyncro Fri May 27, 2016 11:38 am

The resistor is found in the stock van high pressure line coming from the pump.

You absolutely need a restrictor IMO.

tschroeder0 Sat May 28, 2016 9:44 am

I'm new to the zetec/bostig world, but I drive my van A Lot! Since I bought the van about 4-5 months ago, I have put on nearly 6 thousand miles, in all kinds of conditions.
A couple of thoughts: Noise? My bostig with the turbo is amazingly quiet, almost no noticeable engine or power steering noise on the road. All I hear is the wind, tire noise. So, you may want to look into the cause of the noise first.
RPM- @70mph I am at about 3900rpm. I have now run at this speed/RPM for literally days, all day with not so much as a hiccup. So, that would not be a worry to me either.
I just had to make an emergency run from Co to wi- I drove it almost straight through at 65-73mph for about 15hrs. I got 20mpg...great little engine!



Powered by phpBB © 2001, 2005 phpBB Group