Date: Fri, 13 Oct 2006 15:40:50 -0400
Reply-To: Bostig Eng <syncrolist@BOSTIG.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Bostig Eng <syncrolist@BOSTIG.COM>
Subject: Re: Bostig Zetec kit .. Ground clearance
In-Reply-To: <001001c6eee9$5c977be0$fb8bd04b@t41>
Content-Type: text/plain; charset="us-ascii"
When I said skid plate, I meant our skid plate, which is just under 1/2"
thick, and attaches to the cradle.
With the short pan only (which is reinforced as well) you gain about 3/4"-1"
of clearance in the middle, with our skid plate it drops 1/2", but you can
drag the whole thing off rocks all day long and not worry about it.
One thing that is hard to characterize is that since the muffler/cat aren't
there anymore, the departure angle is totally different, and since the
further away from the wheel centerline you go, the more the clearance
matters (generally speaking, pointy narrow rocks being the exception) you
might well avoid some of the scrapes you mentioned entirely.
Since it is such a difficult thing to characterize, and you can't predict
exactly what you are going to encounter, if you feel you are likely to be
dragging the rear of the van in off-road conditions, go for the short pan
and skid plate, then it really doesn't matter if you're bouncing off things
or not, you won't have damage. Also since the exhaust is protected as well,
you won't be putting tears into thin gauge steel as you might with the stock
setup, even if it doesn't tear, a good scrape will rapidly accelerate a
breach caused by rust in the exhaust, and as we all know vanagon exhaust
parts aren't free.
We are going to be posting a video so you can see the skid plate etc over
the weekend.
Thanks,
Jim
________________________________________
Bostig Engineering
Engine Systems Voodoo
http://www.bostig.com/
617.272.3800
-----Original Message-----
From: Larry Chase [mailto:roadguy@ROADHAUS.COM]
Sent: Friday, October 13, 2006 1:02 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Bostig Zetec kit .. Ground clearance
Jim,
As always ... great detailed response.
A couple of f/u questions on clearance.
"add the skid plate and you sac ~1/2" in the center again"
So with the short pan ... we'd loose 1/2" of clearance in the center with
the skid rails?
What about in the back .. Not height but angle.
The trails I travel often result in scrapping the front bumper/tire pan and
the back exhaust area ... from time to time.
Deep narrow and such.
Even though the height difference is ~1/2" the photo looks like maybe the
angle is a bit different and perhaps the carrier would scrape a bit more
than the stock
Config.
http://tinyurl.com/kww56
Actually I'd like to add about 1"2" of ground clearance.
Wild Man Brady's experiences are interesting though.
Wat a great test pilot :)
good road,
good adventure,
good life,
larry chase
www.roadhaus.com
soon to be roadhaus.org
Date: Thu, 12 Oct 2006 09:44:07 -0400
From: Bostig Eng <syncrolist@BOSTIG.COM>
Subject: Re: Bostig Zetec kit...WOW...
Hi All,
To address the concerns about ground clearance, yeah that pic is not
representative, it really does look like it is about to touch the ground.
The base kit will sacrifice ~3/4" in the dead center, but with the short pan
clearance is the same as stock at it's lowest, add the skid plate and you
sac ~1/2" in the center again. The ground clearance as you move up the sides
of the cradle is better than stock. We also include 3/4" rear spring spacers
on all 2wd kits because we have found that most rear springs on customer
vans sag below their stock height to begin with. The 3/4" spacer brings them
back to stock ride height. I've wanted for some time to get a standardized
set of measurements for evaluating clearance, and start building a database
of what folks have on their rides as this is something everyone should
consider when converting.
Brady has gone into more inhospitable ugly rockcrawling, ass-dragging, you
really shouldn't be there situations with the conversion than anybody I've
seen in a vanagon. He's destroyed one pan (did the worst case scenario and
fell on a bowling ball sized rock, right into the pan between the cradle and
the front of the pan) the pan was punched in about 4 inches, the pick did
NOT break, and he proceeded to drive another 1000 miles on it... we had
packed along another $29 pan and $30 pickup to take with just in case on
that one, but wanted to push our luck and drive on it like that. The skid
plate on the cradle with short pan will allow you to drag the entire ass end
of the van off a rock with the front tires(on a syncro) and still let you
drive home fine.
Jonathan mentioned cold air... yes, is a great way to get even more power.
As to why we didn't offer another way, we focused on plugging into the stock
setup, and we do offer the enclosed element airbox, but because of the
restrictive size of the vanagon snorkel block off panel, you end up losing
several wheel HP and ft-lbs of torque if you go this route (even over
pulling under lid air) We are finishing the first cold air kit which is a
variation of what a customer in GA already did for his install:
http://www.thesamba.com/vw/forum/album_page.php?pic_id=292227
With the included datalogger/reflasher he logged a 45 deg. F drop in intake
air temp going this route... so well worth doing as the engine management
will be able to add more spark advance without knock.
As far as the metal tubing causing heat soak, that is a good point. It is
likely the case that you're raising intake air temp by using metal, but the
difference in going with another material or even insulating it is my
experience not worth while(unless we could sell 100,000 of them in which
case we'd make a new intake manifold). Unless the metal is in the path of
lot's of radiant heat from exhaust etc, the benefits to insulating are not
worth a change. This is as I've observed in other turbo applications I've
builts where every bit of power is being wrung out of an engine, and
insulation didn't have a measurable effect and ended up coming out again,
even though it is covering a lot longer run, pushing much greater air masses
with the confines of the engine bay.
In fact we already got lucky with this setup, as the longer intake has a
two-fold effect, it relocates the throttle body which is needed, and it
lengthens the intake tract, which adds power and torque below 3k rpm at the
expense of the top end above 6k(which most people prefer)
The intake temp thing would be worth testing though, as if we datalog total
timing advance along with a thermocouple output on the intake tubing, we
will be able to see if there is an impact, and by exactly how much simply by
insulating, driving, and datalogging.
Thanks,
Jim Akiba
Date: Thu, 12 Oct 2006 09:44:07 -0400
From: Bostig Eng <syncrolist@BOSTIG.COM>
Subject: Re: Bostig Zetec kit...WOW...
Hi All,
To address the concerns about ground clearance, yeah that pic is not
representative, it really does look like it is about to touch the ground.
The base kit will sacrifice ~3/4" in the dead center, but with the short pan
clearance is the same as stock at it's lowest, add the skid plate and you
sac ~1/2" in the center again. The ground clearance as you move up the sides
of the cradle is better than stock. We also include 3/4" rear spring spacers
on all 2wd kits because we have found that most rear springs on customer
vans sag below their stock height to begin with. The 3/4" spacer brings them
back to stock ride height. I've wanted for some time to get a standardized
set of measurements for evaluating clearance, and start building a database
of what folks have on their rides as this is something everyone should
consider when converting.
Brady has gone into more inhospitable ugly rockcrawling, ass-dragging, you
really shouldn't be there situations with the conversion than anybody I've
seen in a vanagon. He's destroyed one pan (did the worst case scenario and
fell on a bowling ball sized rock, right into the pan between the cradle and
the front of the pan) the pan was punched in about 4 inches, the pick did
NOT break, and he proceeded to drive another 1000 miles on it... we had
packed along another $29 pan and $30 pickup to take with just in case on
that one, but wanted to push our luck and drive on it like that. The skid
plate on the cradle with short pan will allow you to drag the entire ass end
of the van off a rock with the front tires(on a syncro) and still let you
drive home fine.
Jonathan mentioned cold air... yes, is a great way to get even more power.
As to why we didn't offer another way, we focused on plugging into the stock
setup, and we do offer the enclosed element airbox, but because of the
restrictive size of the vanagon snorkel block off panel, you end up losing
several wheel HP and ft-lbs of torque if you go this route (even over
pulling under lid air) We are finishing the first cold air kit which is a
variation of what a customer in GA already did for his install:
http://www.thesamba.com/vw/forum/album_page.php?pic_id=292227
With the included datalogger/reflasher he logged a 45 deg. F drop in intake
air temp going this route... so well worth doing as the engine management
will be able to add more spark advance without knock.
As far as the metal tubing causing heat soak, that is a good point. It is
likely the case that you're raising intake air temp by using metal, but the
difference in going with another material or even insulating it is my
experience not worth while(unless we could sell 100,000 of them in which
case we'd make a new intake manifold). Unless the metal is in the path of
lot's of radiant heat from exhaust etc, the benefits to insulating are not
worth a change. This is as I've observed in other turbo applications I've
builts where every bit of power is being wrung out of an engine, and
insulation didn't have a measurable effect and ended up coming out again,
even though it is covering a lot longer run, pushing much greater air masses
with the confines of the engine bay.
In fact we already got lucky with this setup, as the longer intake has a
two-fold effect, it relocates the throttle body which is needed, and it
lengthens the intake tract, which adds power and torque below 3k rpm at the
expense of the top end above 6k(which most people prefer)
The intake temp thing would be worth testing though, as if we datalog total
timing advance along with a thermocouple output on the intake tubing, we
will be able to see if there is an impact, and by exactly how much simply by
insulating, driving, and datalogging.
Thanks,
Jim Akiba
