Date: Sun, 7 Nov 2010 10:31:58 -0500
Reply-To: Greg Potts <greg@POTTSFAMILY.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Greg Potts <greg@POTTSFAMILY.CA>
Subject: Re: Was Smartphone....Now: conventional Dyno for tuning?
In-Reply-To: <AANLkTikvSDOLodPDs8HuTsNLJ-gDX3097w-W0RkaXNg4@mail.gmail.com>
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Hi Don,
When tuning my aircooled bus I have a pre-set route I use down and back
along a local highway. I monitor the CHT gauge vs the speedometer and
determine if I've made anything better or not.
The youtube video I have seen says that the iPhone app computes numbers
that are very, very close to real world quarter mile ET's. But it's not
like I believe everythin I see in a youtube video...
I agree completely about accuracy testing; not much point in using an
instrument that isn't consistent. I think it'd also be VERY important to
get the weight of the vehicle plugged into the app if you want to get a
true HP reading. But if this thing does work out then it could be pretty
helpful... In my experience there are a LOT of iPhones out there in the
Vanagon community.
Happy Trails,
Greg Potts
Toronto, Ontario Canada
197x Westfakia "Bob the Tomato"
1987 Wolfsburg Weekender Hardtop (ND Graphics graphics wrap)
1988 Wolfsburg Weekender Hardtop (Colleen's ride)
www.pottsfamily.ca
BUSES OF THE CORN - AUGUST 12-14th, 2011
www.busesofthecorn.ca
On 11/7/2010 10:04 AM, Don Hanson wrote:
> While I have no experience with Smart phones and their dyno apps, a
> regular dyno is the way to tune, to modify effectively, to quantify actual
> gains as you attempt to improve on your vehicles.
>
> I wish I'd done a baseline dyno run on my recently-revised 1.8 l inline
> motor so I could compare what my actual increase in power has been . Having
> actual numbers 'means' something...Seat of the Pants impressions?....not so
> much. A few hours on a Mustang dyno (the one I am familiar with) after
> every major modification, tuning and tweeking, then you know you have found
> every last hp and lb/ft of torque possible from your latest 'improvement'
> It's quite illuminating. Surprising, too, how much can be gained or lost.
> Also informative to 'de-bunk'. A lot of 'common knowledge' can be shown
> as urban myth. Counter-intuitive changes can sometime give good performance
> improvements. Expensive aftermarket modifications sometimes give no
> meaningful gains. I would love to see some dyno print-outs on all the
> various engines used in Vanagons right now...from the same type dyno. I bet
> we would be surprised at some of the numbers.
>
> The 'work-around' that I use with this Vanagon instead of taking repeated
> trips to Portland for actual 'roller-runs' is to repeat runs up a familiar
> highway with a long (about 4mi) steady 7% upgrade, see what kind of speeds I
> can sustain. Crude. It's so much better to have some real print-outs.
>
> Some folks I know of use a widget called a "G-force". I assume these are
> similar to what you might get with a Smart Phone app....GPS, accelerometer,
> timing and some algorithms. These system's number's don't seem to jibe very
> meaningfully with the performance of the vehicles they are linked to in all
> cases, though I suppose you might get some useful data, percentage-wise..I
> would want to do some 'repeatability testing' to see if you could get the
> same numbers in repeated 'runs' using an I-Phone..An actual inertial
> dyno--that can give us 'apples to apples' numbers without a lot of
> variables.
>
> Don Hanson
>
> On Sat, Nov 6, 2010 at 10:10 PM, David Beierl<dbeierl@attglobal.net> wrote:
>
>> At 12:02 AM 11/7/2010 -0400, Greg Potts wrote:
>>
>>> For $13 it'd be pretty useful to tell you if that $50 widget actually
>>> did make a difference or if it's just a placebo effect...
>>>
>>
>> Are you absolutely sure you want to know?<g>
>>
>> Yrs,
>> David
>>
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