Bay Bus Shift Points

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Amskeptic
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Re: Bay Bus Shift Points

Post by Amskeptic » Tue Jun 04, 2013 6:24 am

Bleyseng wrote:I'd say 5500 rpms in first, second and third as this is where valve float is just starting on a stock type 4.
In reality a stock type4's hp tops out at 4400rpms so that would be the shift point. :compress:
Please do not provide incorrect information as "fact". I know you have had your ear cocked to the Raby Engine Development program, and perhaps the Type 4 Porsche racing community where lots of fast loose information abounds. Some of it is even "useful", but your information must be vetted.

"Valve float is starting at 5,500 rpm"? Whose valve spring pressures? If some engine has been beating on valve springs for thousands of miles, sure, a little valve float may occur. But you cannot tell me the factory specified valve spring pressures were giving it up at 5,500 rpm, not when your own 914 has a redline at 5,800.

"In reality, a stock Type 4's hp tops out at 4,400"? Again, the 1700s were peaking at 4,800 rpm, the 1700 Porsche and 411s were peaking at 4,900 rpm. The 2.0 engines were at 4,200-4,300 rpm.

What is the published stock hp/RPM of the Porsche 914 2.0?

Please do not make sweeping generalizations that blanket over the factory specifications published the world over. Many engines have exceeded the factory specs, because of the politics of output versus taxes! So Mercedes has been under-reporting output since Germany taxes based on output, while the phallically challenged Chrysler boys were over-reporting the Hemi's output, and Ford and GM were d**ksizing the musclecar hp readings right off the theoretical numbers! That is why we had to standardize in 1973 with the SAE net ratings off the flywheel with all ancillaries bolted up.

In reality, I have only run across a few Type 4 engines that were anywhere tuned well enough to put out the factory horsepower.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Bleyseng
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Re: Bay Bus Shift Points

Post by Bleyseng » Tue Jun 04, 2013 9:25 am

Amskeptic wrote:
Bleyseng wrote:I'd say 5500 rpms in first, second and third as this is where valve float is just starting on a stock type 4.
In reality a stock type4's hp tops out at 4400rpms so that would be the shift point. :compress:
Ok, the TWO Liter bus type 4 engine. In reality, I haven't seen a unmolested factory built 1700 in years so they don't count.)
Amskeptic wrote: Please do not provide incorrect information as "fact". I know you have had your ear cocked to the Raby Engine Development program, and perhaps the Type 4 Porsche racing community where lots of fast loose information abounds. Some of it is even "useful", but your information must be vetted.
I have been working on/rebuilding VW engines since 1969 when we just went and bought all new VW parts (wholesale) to rebuild engines including cases. I entered the 914 stuff in 1995 Autocrossing and learning how to squeeze extra hp and torque out of the type 4 from several local racer types. Yep, I am not a stock engine guy as you can't buy those great German VW parts anymore!
Amskeptic wrote: "Valve float is starting at 5,500 rpm"? Whose valve spring pressures? If some engine has been beating on valve springs for thousands of miles, sure, a little valve float may occur. But you cannot tell me the factory specified valve spring pressures were giving it up at 5,500 rpm, not when your own 914 has a redline at 5,800.
I can tell you this as the springs do start giving up the ghost at 5500 and valve float starts there. Porsche installed the 5400 rpms rev limiter in 914 to stop owners from over reving their engines. Look at the published hp charts and the hp curve drops off a cliff at 5000 rpms.
Amskeptic wrote: "In reality, a stock Type 4's hp tops out at 4,400"? Again, the 1700s were peaking at 4,800 rpm, the 1700 Porsche and 411s were peaking at 4,900 rpm. The 2.0 engines were at 4,200-4,300 rpm.
Again, I am speaking about 2.0L engines especially since I have seen one 411 in my life. The 2.0L bus cam is the limiting factor in a stock 2.0L bus. Using the Web 142 (stock 914 2.0L cam grind) improves the top end of the bus 2.0L without hurting the low end. The 411's had a great carb cam that became the Web73/R9550 cam and also a modified version was in the early 1700 bus motors. This info was on Shoptalk years ago. That's why those motors rev so nicely vs the (crappy to me) 2.0L bus solid and hydro cams as they top out at 4300rpms. Next time we meet up its time for you to drive my Westy as its like a rev happy 1700 with lots of hp and torque)
Amskeptic wrote: What is the published stock hp/RPM of the Porsche 914 2.0?
95hp @4900rpms but the best I have ever seen on a dyno is 88hp)
Amskeptic wrote: Please do not make sweeping generalizations that blanket over the factory specifications published the world over. Many engines have exceeded the factory specs, because of the politics of output versus taxes! So Mercedes has been under-reporting output since Germany taxes based on output, while the phallically challenged Chrysler boys were over-reporting the Hemi's output, and Ford and GM were d**ksizing the musclecar hp readings right off the theoretical numbers! That is why we had to standardize in 1973 with the SAE net ratings off the flywheel with all ancillaries bolted up.

In reality, I have only run across a few Type 4 engines that were anywhere tuned well enough to put out the factory horsepower.
Colin
I totally agree! but I have roller dyno'd my 914 with its souped up 2.1L and will dyno my Westy one of these days to back up my blanket generalizations so I don't have to rely on factory numbers.
Geoff
77 Sage Green Westy- CS 2.0L-160,000 miles
70 Ghia vert, black, stock 1600SP,- 139,000 miles,
76 914 2.1L-Nepal Orange- 160,000+ miles
http://bleysengaway.blogspot.com/

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Re: Bay Bus Shift Points

Post by Amskeptic » Thu Jun 06, 2013 8:53 pm

Bleyseng wrote:
Porsche installed the 5400 rpms rev limiter in 914 to stop owners from over revving their engines. Look at the published hp charts and the hp curve drops off a cliff at 5000 rpms.
The Porsches and 411s had a 5800 rev limiting rotor, 5400 rotor on the buses.
Bleyseng wrote:
Amskeptic wrote: "In reality, a stock Type 4's hp tops out at 4,400"? Again, the 1700s were peaking at 4,800 rpm, the 1700 Porsche and 411s were peaking at 4,900 rpm. The 2.0 engines were at 4,200-4,300 rpm.
Again, I am speaking about 2.0L engines especially since I have seen one 411 in my life. The 2.0L bus cam is the limiting factor in a stock 2.0L bus.Next time we meet up its time for you to drive my Westy as its like a rev happy 1700 with lots of hp and torque)
I will be happy to drive your Westy. We can do the 50-70 time trial at the top of the hill both directions to compensate for wind.
Colin :compress:
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Re: Bay Bus Shift Points

Post by locoqueso » Mon Jun 10, 2013 10:29 am

This post was very helpful. I really appreciate the illustrations to back up the info. I'm looking forward to the book!
1978 VW Campmobile (P-21) Westfalia - T2 2.0L F.I.- 151,000m
1982 Mercedes-Benz Estate Wagon (300TD-T) - S123 3.0L T.D. - 142,000m
1993 Dodge Maxi Van (190 SLF) InterVec Falcon - B350 Magnum 5.9L F.I. - 70,000m

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Re: Bay Bus Shift Points

Post by Amskeptic » Wed Jun 19, 2013 10:11 pm

locoqueso wrote:This post was very helpful. I really appreciate the illustrations to back up the info. I'm looking forward to the book!
Heyer Loco,
I am going to try 69 mph in 3rd in the BobD. Then we will know what the owner's manual is talking about when it says you may accelerate briefly in 2nd and 3rd gear beyond the recommended ranges "there is a governor to protect the engine".

In the Road Warrior, I hit the governor at 59 mph in 3rd with a 1700 and a 5.38 rear axle.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Re: Bay Bus Shift Points

Post by Westy78 » Thu Jun 20, 2013 10:45 am

Amskeptic wrote:
locoqueso wrote:This post was very helpful. I really appreciate the illustrations to back up the info. I'm looking forward to the book!
Heyer Loco,
I am going to try 69 mph in 3rd in the BobD. Then we will know what the owner's manual is talking about when it says you may accelerate briefly in 2nd and 3rd gear beyond the recommended ranges "there is a governor to protect the engine".

In the Road Warrior, I hit the governor at 59 mph in 3rd with a 1700 and a 5.38 rear axle.
Colin
Don't you have to have the special rotor in carbed engines for the rev limiter to work? Vaguely in my mind I seem to remember reading somewhere that the ECU in the FI engines also had some sort of limiter built in?
Chorizo, it's what's for breakfast.

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Re: Bay Bus Shift Points

Post by Amskeptic » Fri Jun 21, 2013 11:56 am

Westy78 wrote:
Amskeptic wrote:
locoqueso wrote:This post was very helpful. I really appreciate the illustrations to back up the info. I'm looking forward to the book!
Heyer Loco,
I am going to try 69 mph in 3rd in the BobD. Then we will know what the owner's manual is talking about when it says you may accelerate briefly in 2nd and 3rd gear beyond the recommended ranges "there is a governor to protect the engine".

In the Road Warrior, I hit the governor at 59 mph in 3rd with a 1700 and a 5.38 rear axle.
Colin
Don't you have to have the special rotor in carbed engines for the rev limiter to work? Vaguely in my mind I seem to remember reading somewhere that the ECU in the FI engines also had some sort of limiter built in?
I had the 5400 limiter rotor in the Road Warrior for its entire life. Lubricated with silicone grease to make sure it shorted the rotor on time. It had a simple weighted slide against a spring tension that would reach the end of its travel and kill the spark. Nifty.

Image

As soon as VW was required to equip their engines with catalytic converters (1975 CA), the ignition-based rev limiter was a no-no. Imagine cutting ignition at 5,400 rpm . . . all that fuel slamming into the catalytic converter :angryfire:

The L-Jet ECU allegedly limits revs by soft fuel cut-off at the injectors.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Bleyseng
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Re: Bay Bus Shift Points

Post by Bleyseng » Fri Jun 21, 2013 10:33 pm

Amskeptic wrote: As soon as VW was required to equip their engines with catalytic converters (1975 CA), the ignition-based rev limiter was a no-no. Imagine cutting ignition at 5,400 rpm . . . all that fuel slamming into the catalytic converter :angryfire:

The L-Jet ECU allegedly limits revs by soft fuel cut-off at the injectors.
Colin
Allegedly is correct as mine revs to 6000rpms without any cutout unless I put the rev limiter rotor back in for when I let other people drive.
Geoff
77 Sage Green Westy- CS 2.0L-160,000 miles
70 Ghia vert, black, stock 1600SP,- 139,000 miles,
76 914 2.1L-Nepal Orange- 160,000+ miles
http://bleysengaway.blogspot.com/

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Re: Bay Bus Shift Points

Post by Amskeptic » Tue Jun 25, 2013 9:16 am

Bleyseng wrote:
Amskeptic wrote: As soon as VW was required to equip their engines with catalytic converters (1975 CA), the ignition-based rev limiter was a no-no. Imagine cutting ignition at 5,400 rpm . . . all that fuel slamming into the catalytic converter :angryfire:

The L-Jet ECU allegedly limits revs by soft fuel cut-off at the injectors.
Colin
Allegedly is correct as mine revs to 6000rpms without any cutout unless I put the rev limiter rotor back in for when I let other people drive.
Which vehicle?
The Porsche?
The Porsche stuck with the 5,800 rpm rev limiting rotor because it did not have a catalytic converter.

The bus?
Who the hell is doing 6,000 rpm in the bus?
Fess up! :pirate:

091 Transaxle Speeds @ 6,000 RPM.
..1.....2.....3......4
25 / 47 / 77 / 109 mph
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Re: Bay Bus Shift Points

Post by Bleyseng » Tue Jun 25, 2013 5:06 pm

The 2.0L Westy! I can't detect any rev limitation with it. The 914 has none either using the stock Djet and will rev to 6500rpms with the heavy duty valve springs without any problem. The stock 76 914 had a speed limiter box on the FI harness and I have one laying around if you want a pic. Yes, I install a rev limiter in the Westy (5400) if I let others drive it (rarely), the 914 is such a strange animal to drive with the 901 shift pattern I don't let other people drive it as they always shift from 1st into reverse!
Geoff
77 Sage Green Westy- CS 2.0L-160,000 miles
70 Ghia vert, black, stock 1600SP,- 139,000 miles,
76 914 2.1L-Nepal Orange- 160,000+ miles
http://bleysengaway.blogspot.com/

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Re: Bay Bus Shift Points

Post by Amskeptic » Fri Jun 28, 2013 7:49 am

Bleyseng wrote:The 2.0L Westy!
Really?? I will be ginger with my BobD experiments. You have original ECU?

Bleyseng wrote: I can't detect any rev limitation with it.
Have you actually hit the rev limit speeds in whatever gear?
You have to do 69 in 3rd to hit the factory rev limiter. Why don't you do the experiment on your bus, then I won't have to.
Colin :blackeye:
(thanx!)
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Re: Bay Bus Shift Points

Post by Bleyseng » Fri Jun 28, 2013 11:39 am

I tried it this morning hitting 6000rpms in second gear with my Factory Stock to this 77 Westy ECU. It runs out of breath but no "limiting" type action is felt like if I have the rev limit rotor installed which shuts off when you reach the rpm.
Do you have the 4500 rev limit rotor in Cloe? I saw those were stock for 71 buses for some reason....
Geoff
77 Sage Green Westy- CS 2.0L-160,000 miles
70 Ghia vert, black, stock 1600SP,- 139,000 miles,
76 914 2.1L-Nepal Orange- 160,000+ miles
http://bleysengaway.blogspot.com/

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Re: Bay Bus Shift Points

Post by Amskeptic » Mon Jul 01, 2013 9:03 am

Bleyseng wrote:I tried it this morning hitting 6000rpms in second gear with my Factory Stock to this 77 Westy ECU. It runs out of breath but no "limiting" type action is felt like if I have the rev limit rotor installed which shuts off when you reach the rpm.
Do you have the 4500 rev limit rotor in Cloe? I saw those were stock for 71 buses for some reason....
Airkooledchris and I hit the factory rev-limiter on his factory L-Jet '79 Bus the day before yesterday. Sounds like countless rally cars do bup-bup-bup-bup, soft shut-off of the injectors coming from the ECU.

As, posted, 6,000 rpm in 2nd gear is 47 mph. Is that what you hit? Really?
I have no idea what is going on with your cars.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Bleyseng
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Re: Bay Bus Shift Points

Post by Bleyseng » Mon Jul 01, 2013 10:01 am

yes, I did just to see and I'll try it again this morning driving around "just to see". Maybe that's a 79 yr thing? I do it entering the freeway when the oils hot.
Urban legend on 914 Djet was it had this too at 5500rpms but its not true as it runs up fine to 6500rpms but slowly leans out as the revs climb to 13.5 to 1 at WOT. So its the injectors maybe running out of gas not the Djet built in rev limiter unless its the 76 model w/speedlimitor.
Geoff
77 Sage Green Westy- CS 2.0L-160,000 miles
70 Ghia vert, black, stock 1600SP,- 139,000 miles,
76 914 2.1L-Nepal Orange- 160,000+ miles
http://bleysengaway.blogspot.com/

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Re: Bay Bus Shift Points

Post by airkooledchris » Mon Jul 01, 2013 12:59 pm

The 79 I have is California specific, not that I think it should matter, but you never know, as they did some other things different with this system.

I wasn't in gear at the time we hit it either, the throttle cable was stuck in the floored position and it just wound up and started bouncing on the limiter (WAAAAA NA NA NA NA NA NA NA NA) until the cable was freed up. That's probably the easier test to do, just floor it in neutral while your in the driveway with the e-brake on and see what happens when you hold it there for a few seconds.
1979 California Transporter

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