| Author |
Message |
BFB
Samba Member
Joined: November 03, 2014
Posts: 2804
|
 Posted: Fri Feb 16, 2024 4:27 pm Post subject: Dyno day |
 |
|
If anyone is in the area and interested, im thinking of setting up a dyno day this summer. I recently talked to a guy that owns a dyno shop and he’s all for it, i just need to pick a day.
It’d be in S.W. Missouri and i plan to foot the bill so all youd have to do is show up. Vw shit only & its not intended as a time for anyone to spend hours on the machine tuning their car , just run it and see what hp your making and let the next guy have a go.
_________________
"how am i supposed to torque the rear wheel nut to 250 ft lbs??? " - clonebug
An interesting thing happens in forums where everyone starts parroting the same thing and "common knowledge" takes over.
Most experts aren't. |
|
| Back to top |
|
 |
RandyV
Samba Member
Joined: November 23, 2019
Posts: 385
Location: So Cal
|
| Posted: Fri Feb 16, 2024 8:04 pm Post subject: Re: Dyno day |
|
|
I don't live out your way but would take you up on it if I did!! That's a very, very cool offer!!
For anyone who hasn't done it, it's a blast!
Empi will be doing it again this year after a year off and it's well worth it.
2 years ago we had everything from 60hp stockers to 600hp bugs. (yes, 600hp) 
And it's as much a spectator sport as anything....(heck I'd probably be hosting over/under betting on the side for guessing #'s) 
Should be an awesome time and again....very kind of you to offer!!!  |
|
| Back to top |
|
|
chrisflstf
Samba Member
Joined: February 10, 2004
Posts: 4123
Location: San Diego
|
| Posted: Sat Feb 17, 2024 9:32 am Post subject: Re: Dyno day |
|
|
| Is this a chassis or engine dyno? How much loss in power comes from the trans, etc? Typically? Do buses have more loss than a bug due to the rgb`s. Just curious |
|
| Back to top |
|
|
Vanapplebomb
Samba Member
Joined: November 03, 2010
Posts: 5572
Location: Holland, MI
|
| Posted: Sat Feb 17, 2024 10:04 am Post subject: Re: Dyno day |
|
|
| chrisflstf wrote: |
| Is this a chassis or engine dyno? How much loss in power comes from the trans, etc? Typically? Do buses have more loss than a bug due to the rgb`s. Just curious |
Although more prone to error, well setup chassis dynos correct for this by spinning down. They measure the deceleration of the roller when power is removed, which they translate to losses in the drive train and tires. That approximation is added to the measured power during acceleration. It’s no DIN or SAE measurement standard, but it gets you pretty darn close.
_________________
1800 Type 4 Berrien 295
http://www.thesamba.com/vw/forum/viewtopic.php?t=487021 |
|
| Back to top |
|
|
jpaull
Samba Member
Joined: February 22, 2005
Posts: 3650
Location: Paradise, Ca
|
| Posted: Sat Feb 17, 2024 11:06 am Post subject: Re: Dyno day |
|
|
Its a chassis dyno because he mentioned not spending time tuning the "car". A chassis dyno is best suited for quick runs and way easier then loading and unloading engines and all thats needed to get a engine setup on a engine dyno.
Thats a pretty awesome and generous offer!!
_________________
[email protected] MPH 1/4 Mile & 8.1 @ 83.7MPH in 1/8 Mile with Mild Type 1 VW Mag Case 2234cc commuter engine in stock weight bug w/only .491 total lift(CB2292 Cam), 42x37 heads, 48idf's, Street tires, Belt on, Mufflers, Pump gas, video of the run here: https://youtu.be/M3SPqMOKAOg
Transmission by MCMScott:
Rhino case, Klinkenberg 4.12, Superdiff, 002 mainshaft with 091 first idler. Weddle 1.48 Third & 1.14 Fourth. |
|
| Back to top |
|
|
vwracerdave
Samba Member
Joined: November 11, 2004
Posts: 15601
Location: Deep in the 405
|
| Posted: Sat Feb 17, 2024 11:58 am Post subject: Re: Dyno day |
|
|
It has been reported by many engine builders you get 17%-20% loss through the drivetrain on a chassis dyno as opposed to an engine dyno.
_________________
2017 Street Comp Champion - Thunder Valley Raceway Park - Noble, OK
2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK |
|
| Back to top |
|
|
Alstrup
Samba Member
Joined: July 12, 2007
Posts: 7873
Location: Videbaek Denmark
|
| Posted: Sat Feb 17, 2024 12:55 pm Post subject: Re: Dyno day |
|
|
| Vanapplebomb wrote: |
Although more prone to error, well setup chassis dynos correct for this by spinning down. They measure the deceleration of the roller when power is removed, which they translate to losses in the drive train and tires. That approximation is added to the measured power during acceleration. It’s no DIN or SAE measurement standard, but it gets you pretty darn close. |
Actually, it is a Din standard. I forget the number. You can look it up.
That said, most US produced chassis dyno´s do not have this option in the software. I beleive the newer Dynojet have the software. Then the question is, are the rollers weighed in and calibrated(?)
The transmission loss is typically in the range Dave mentioned, but it can be as low as 14% and as high as 30%. It all depends. But it is still good fun
_________________
https://www.thesamba.com/vw/forum/viewtopic.php?t=435993 |
|
| Back to top |
|
|
Vanapplebomb
Samba Member
Joined: November 03, 2010
Posts: 5572
Location: Holland, MI
|
| Posted: Sat Feb 17, 2024 1:04 pm Post subject: Re: Dyno day |
|
|
To your point, they often aren’t calibrated well. You can always tell they are off when Hp and Torque don’t cross near 5252 rpm. I have seen some pulls several hundred RPM off. 
_________________
1800 Type 4 Berrien 295
http://www.thesamba.com/vw/forum/viewtopic.php?t=487021 |
|
| Back to top |
|
|
gt1953
Samba Member
Joined: May 08, 2002
Posts: 13948
Location: White Mountains Arizona
|
| Posted: Sat Feb 17, 2024 1:41 pm Post subject: Re: Dyno day |
|
|
The fellow that built my stock 1600 dual port has an engine dyno...it produced 60 hp at the fly wheel at 7000 feet elevation...then on the dyno where the wheels of the car on the giant roller and the car strapped down. SAme engine in the care produced 48 Hp to the ground.
A dyno day is fun.
_________________
Volkswagen: We tune what we drive.
Numbers Matching VW's are getting harder to find. Source out the most Stock vehicle and keep that way. You will be glad you did.
72 type 1
72 Squareback
({59 Euro bug, 62, 63, 67, 68, 69, 73 type ones 68 & 69 type two, 68 Ghia all sold}) |
|
| Back to top |
|
|
Alstrup
Samba Member
Joined: July 12, 2007
Posts: 7873
Location: Videbaek Denmark
|
| Posted: Sat Feb 17, 2024 1:50 pm Post subject: Re: Dyno day |
|
|
OK. BUT, then I HAVE to ask, was it a steady state measue or a powersweep on the engine dyno? Reason is, that a steady state measure is always higher than a powersweep. I do not recall how much, but there is a noticeable difference.
If we look at your numbers and calculate without skewing to which method is used you have a 25% drivetrain loss.
_________________
https://www.thesamba.com/vw/forum/viewtopic.php?t=435993 |
|
| Back to top |
|
|
BFB
Samba Member
Joined: November 03, 2014
Posts: 2804
|
| Posted: Sat Feb 17, 2024 7:22 pm Post subject: Re: Dyno day |
|
|
Yes it is a chassis dyno but not the type with the roller, this one bolts to the vehicle’s hubs.
Sorry for my ignorance but i dont know enough about them to know the names of the different types.
_________________
"how am i supposed to torque the rear wheel nut to 250 ft lbs??? " - clonebug
An interesting thing happens in forums where everyone starts parroting the same thing and "common knowledge" takes over.
Most experts aren't. |
|
| Back to top |
|
|
Alstrup
Samba Member
Joined: July 12, 2007
Posts: 7873
Location: Videbaek Denmark
|
| Posted: Sun Feb 18, 2024 2:49 am Post subject: Re: Dyno day |
|
|
Ohh. Its called a hub dyno. They can handle a lot of hp. But they cant measure transmission loss. But, what you see is what you get as there are no wheel slip and tyre drag from improper alignment etc.
Make sure they have the adapters to the bolt patterns "we" use.
_________________
https://www.thesamba.com/vw/forum/viewtopic.php?t=435993 |
|
| Back to top |
|
|
vwracerdave
Samba Member
Joined: November 11, 2004
Posts: 15601
Location: Deep in the 405
|
| Posted: Sun Feb 18, 2024 8:26 am Post subject: Re: Dyno day |
|
|
All dyno numbers can be manipulated. Weather conditions also has a factor in HP numbers. The most accurate number is your ET at the drag strip. The time clock doesn't lie to anybody.
_________________
2017 Street Comp Champion - Thunder Valley Raceway Park - Noble, OK
2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK |
|
| Back to top |
|
|
Alstrup
Samba Member
Joined: July 12, 2007
Posts: 7873
Location: Videbaek Denmark
|
| Posted: Sun Feb 18, 2024 8:55 am Post subject: Re: Dyno day |
|
|
No offense, but that is at least the 3rd or 4rth time you bring that postulate. And it is SO NOT right. - Well, it is if you want to look at how fast your car is on the strip, here you have the human factor on top of all the rest. Also it does not show how the engine performs in the lower to mid rpms which is where you use it on regular driving.
As for manipulating the numbers, sure, but then the number number you get is not calibrated anymore.
Of course enviromental factors have to be calculated in when doing a test. Do you take that into account when you go dragracing??? - No you don´t, so the numbers you get are already skewed there. Also, do you calculate the drag Cof of the car? Probably not.
_________________
https://www.thesamba.com/vw/forum/viewtopic.php?t=435993 |
|
| Back to top |
|
|
vwracerdave
Samba Member
Joined: November 11, 2004
Posts: 15601
Location: Deep in the 405
|
| Posted: Sun Feb 18, 2024 10:31 am Post subject: Re: Dyno day |
|
|
| Alstrup wrote: |
| Of course enviromental factors have to be calculated in when doing a test. Do you take that into account when you go dragracing??? - No you don´t, |
Yes I do. I have a weather station and record the data on every pass in my log book. With my log book and experience I can look at my times from the last pass and the current weather conditions and predict my ET. The track also has an iPhone app to see all your times and weather conditions for all the racing you do the entire day. I can look at my incremental times (60', 330', 660', and 1000') and see where my car is falling off, or how bad I drove.
There are internet calculators that use your vehicle weight, ET, and MPH and tell you how much HP you make. According to many racers and engine builders they are pretty accurate.
Yes there are factors in driving skill and traction, but the time clock does not lie.
Dyno numbers are very important for you to tune your car, but don't mean a lot when comparing them with other cars.
BFB, I hope you get a good turnout. It can be very fun day with guessing and side betting on what each car will make. Make a party out of it. Have somebody bring a grill and cook some hot dogs.
_________________
2017 Street Comp Champion - Thunder Valley Raceway Park - Noble, OK
2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK |
|
| Back to top |
|
|
BFB
Samba Member
Joined: November 03, 2014
Posts: 2804
|
| Posted: Sun Feb 18, 2024 11:31 am Post subject: Re: Dyno day |
|
|
| vwracerdave wrote: |
…….
BFB, I hope you get a good turnout. It can be very fun day with guessing and side betting on what each car will make. Make a party out of it. Have somebody bring a grill and cook some hot dogs. |
Thanks, hope so too. Majority of the vw guys i know own rails and getting these people together is like herding cats. I’m hoping other people with vw’s show too though, even if it’s something stock
Alstrup, yeh the guy that owns the dyno shop said he’d purchase the adapters. I thought that was pretty cool of him.
_________________
"how am i supposed to torque the rear wheel nut to 250 ft lbs??? " - clonebug
An interesting thing happens in forums where everyone starts parroting the same thing and "common knowledge" takes over.
Most experts aren't. |
|
| Back to top |
|
|
gt1953
Samba Member
Joined: May 08, 2002
Posts: 13948
Location: White Mountains Arizona
|
| Posted: Sun Feb 18, 2024 3:16 pm Post subject: Re: Dyno day |
|
|
I happen to like the numbers that both the engine dyno and the big roller dyno provided. Nope not a drag racer.
_________________
Volkswagen: We tune what we drive.
Numbers Matching VW's are getting harder to find. Source out the most Stock vehicle and keep that way. You will be glad you did.
72 type 1
72 Squareback
({59 Euro bug, 62, 63, 67, 68, 69, 73 type ones 68 & 69 type two, 68 Ghia all sold}) |
|
| Back to top |
|
|
chrisflstf
Samba Member
Joined: February 10, 2004
Posts: 4123
Location: San Diego
|
| Posted: Sun Feb 18, 2024 3:24 pm Post subject: Re: Dyno day |
|
|
Any tips for a first time Dyno user?
Besides tires ok, motor/trans up to temp. All tuned and ready to go
Do I need a tach in the Bus? |
|
| Back to top |
|
|
67rustavenger
Samba Member
Joined: February 24, 2015
Posts: 11247
Location: Oregon
|
| Posted: Sun Feb 18, 2024 4:22 pm Post subject: Re: Dyno day |
|
|
| chrisflstf wrote: |
Any tips for a first time Dyno user?
Besides tires ok, motor/trans up to temp. All tuned and ready to go
Do I need a tach in the Bus? |
For a rolling road (Chassis) dyno. I'd say decent tires are a must.
Get the tune as good as you can. You're paying for the dyno time. Asking the dyno operator to tune your engine will cost you $$$ and time to get your engine sorted.
Make sure to ask the operator if you can tune at the shop or if you are just running the numbers to see what you have.
They hopefully can advise you on what the engine needs to get the most of what you are trying to achieve from your dyno session.
If the dyno operators shop is unfamiliar with tuning ACVW's and you have dual carbs. Bring along some extra carb jets to make adjustments, if the operator is helping get the engine sorted.
An afr bung welded in the exhaust system would be helpful too.
The tach issue will be tracked by the dyno software, if so equipped.
_________________
I have learned over the years.
Cheap parts are gonna disappoint you.
Buy Once, Cry Once!
There's never enough time to do it right the first time. But there's always enough time to do it thrice.
GFY's Xevin and VW_Jimbo!
2003 Astrovan? GFYS again, Xevin!
Don't let your bad ideas remain, ideas! |
|
| Back to top |
|
|
richparker
Samba Member
Joined: November 24, 2011
Posts: 7567
Location: Durango, CO
|
|
| Back to top |
|
|
|
