5 speed better or worse for a turbo engine.
- theKbStockpiler
- Posts: 596
- Joined: Sun Jul 15, 2012 10:25 am
5 speed better or worse for a turbo engine.
The title says it all. I have the parts to do a 914 5 speed conversion but was wondering if it might be a step in wrong direction. I hear that when big block owners go with a supercharger they actually prefer a 3 speed over 4 because of the broad torque curve. A turbo is generally stated as being best at boosting at higher RPM's though.
Thanks for your input.
Thanks for your input.
Super beetle with attitude
- panel
- Posts: 4201
- Joined: Sun Sep 24, 2000 12:01 am
Re: 5 speed better or worse for a turbo engine.
What's the ratios of the 4spd? And what ratios for the 5spd ?
'65 Bus with a JDM Subaru EJ20 Turbo
Built by Germans powered by Japanese and brought together by Canadians
Built by Germans powered by Japanese and brought together by Canadians
-
- Posts: 4720
- Joined: Thu Feb 15, 2007 9:28 pm
Re: 5 speed better or worse for a turbo engine.
The 914 5 speed is a slower shifting transmission.......which takes longer to get back on boost.
Ask Mario how fast my 67 trans will shift........
Ask Mario how fast my 67 trans will shift........
Stripped66 wrote:The point wasn't to argue air temps with the current world record holder, but to dispel the claim that the K03 is wrapped up at 150 HP. It's not.
- theKbStockpiler
- Posts: 596
- Joined: Sun Jul 15, 2012 10:25 am
Re: 5 speed better or worse for a turbo engine.
Is it just to get it over the 1st/Reverse gate or overall?
Also the five speed is basically evenly spaced between gears If I remember right with final gear being the same as the 4 speed.
Here's the 5 speed specs. I'll post the 4 speed vw later.
Transmission type(s): 914 (300.01, 300.05, 300.11, 300.12)
Original equipment for: Porsche 914 70-72 w/tail shift or 73-76 w/side shift
Description: 5 speed H pattern manual transaxle with early Porsche synchromesh and dog leg 1st gear
Limited Slip Differential: A ZF 40-80% LSD was optional equipment
Speedometer: Mechanical
Transmission controls: Rod linkage
Clutch: Mechanical/cable, push clutch, 215mm single plate
Oil capacity: Approx 2.5L hypoid SAE 90
Weight: Approx 119lbs
Stock gear ratios:
1970-1976 914/4: 11:34 A, 18:34 F, 23:29 N, 27:25 V, 31:22 ZD Or approximately 3.09 1.89 1.26 .926 .71
Final drive 7:31 Or approximately 4.428
4 speed beetle
Also the five speed is basically evenly spaced between gears If I remember right with final gear being the same as the 4 speed.
Here's the 5 speed specs. I'll post the 4 speed vw later.
Transmission type(s): 914 (300.01, 300.05, 300.11, 300.12)
Original equipment for: Porsche 914 70-72 w/tail shift or 73-76 w/side shift
Description: 5 speed H pattern manual transaxle with early Porsche synchromesh and dog leg 1st gear
Limited Slip Differential: A ZF 40-80% LSD was optional equipment
Speedometer: Mechanical
Transmission controls: Rod linkage
Clutch: Mechanical/cable, push clutch, 215mm single plate
Oil capacity: Approx 2.5L hypoid SAE 90
Weight: Approx 119lbs
Stock gear ratios:
1970-1976 914/4: 11:34 A, 18:34 F, 23:29 N, 27:25 V, 31:22 ZD Or approximately 3.09 1.89 1.26 .926 .71
Final drive 7:31 Or approximately 4.428
4 speed beetle
Super beetle with attitude
-
- Posts: 3146
- Joined: Mon Jul 24, 2006 3:11 pm
Re: 5 speed better or worse for a turbo engine.
I luv the stock gear ratio in my 76 wouldn't want anything with a 4:42 or even a 4:12
wider the ratio the better for the load
wider the ratio the better for the load
-
- Posts: 38
- Joined: Wed Mar 05, 2008 12:35 am
Re: 5 speed better or worse for a turbo engine.
I used to have (still have in the workshop) a 901 5 speed in my beetle (same box as the 914 tail shift box but with the diff reversed) however i managed to break 1st twice with about 80 hp I had slightly different ratios when it was rebuild than a stock one, with my tyre size it was basically like a 1200 box 1-4 then a bit longer than a 1600 box in top was nice but not really very strong, although im sure if i was more careful it would have been better.
when it comes to racing i prefer longer gears to load the turbo up and have less gear changes, it really depends on the powerband you end up with on my drag golf i use a Diesel gearbox simply because i couldn't do the 1st gear change quickly enough to not mess it up every other time.
when it comes to racing i prefer longer gears to load the turbo up and have less gear changes, it really depends on the powerband you end up with on my drag golf i use a Diesel gearbox simply because i couldn't do the 1st gear change quickly enough to not mess it up every other time.
- theKbStockpiler
- Posts: 596
- Joined: Sun Jul 15, 2012 10:25 am
Re: 5 speed better or worse for a turbo engine.
Were you dumping the clutch or just hard acceleration? How wide are your rear tires?64 sunroof wrote: ↑Mon Mar 05, 2018 4:42 am I used to have (still have in the workshop) a 901 5 speed in my beetle (same box as the 914 tail shift box but with the diff reversed) however i managed to break 1st twice with about 80 hp
Super beetle with attitude
- woodsbuggy1
- Posts: 820
- Joined: Sun Feb 20, 2011 5:15 pm
Re: 5 speed better or worse for a turbo engine.
I bet a 6 or 7 speed would be even better, the more time you spend shifting gears the less time you will be on boosts.
Sorry, don't mean to sound like a jerk but just look at what works for the guys that are serious and copy as much as you can.
Good Luck
Kenric
Sorry, don't mean to sound like a jerk but just look at what works for the guys that are serious and copy as much as you can.
Good Luck
Kenric
Good quality is getting harder and harder to find.
- Chip Birks
- Posts: 4008
- Joined: Wed Mar 12, 2008 5:59 pm
Re: 5 speed better or worse for a turbo engine.
I run a 4 speed in mine. No reason to run a 5 speed, it has more than enough get up and go to pull long gears. Mine are slightly shorter than stock, but i run a taller tire that stock too. The added cost of converting to anything Porsche makes very little sense in my mind.
- theKbStockpiler
- Posts: 596
- Joined: Sun Jul 15, 2012 10:25 am
Re: 5 speed better or worse for a turbo engine.
The 901 5 speed has a weak first gear but some people think it would be okay to do hard launches with 195 tires on it. I just did a thread on Pelican Parts and the respondents are telling me it's pretty easy to snap off the main shaft with even a 80hp motor. A new shaft is $1500.
I guess I will plan on shelving the 901 idea and let a 914 owner have a chance to break it up instead of me. I liked the way my old 74 ;with a 4 speed ,drove around town anyways.
I guess I will plan on shelving the 901 idea and let a 914 owner have a chance to break it up instead of me. I liked the way my old 74 ;with a 4 speed ,drove around town anyways.
Last edited by theKbStockpiler on Wed Mar 07, 2018 4:48 pm, edited 1 time in total.
Super beetle with attitude
- petew
- Posts: 3920
- Joined: Sat Oct 07, 2006 4:05 pm
Re: 5 speed better or worse for a turbo engine.
901s would be starting to be valuable with the concourse Porsche crowd wouldn't they? I'd sell it off and buy a Subaru if you really want a 5 speed. But like most people here, the stocker late AB trans are my pick. Just make sure you go with a 3:88 R&P. Wish I'd done that now.
- buguy
- Posts: 6209
- Joined: Wed Jan 26, 2005 8:53 pm
Re: 5 speed better or worse for a turbo engine.
I bet 3:88's would be great! My stock 65 first gear is useless! I can let the clutch out with no gas input without stalling.... easy. Even before the turbo. It would be a great car to learn to drive a stick in!
- theKbStockpiler
- Posts: 596
- Joined: Sun Jul 15, 2012 10:25 am
Re: 5 speed better or worse for a turbo engine.
The low 1st is a blessing to get going on a hill.
Super beetle with attitude
- buguy
- Posts: 6209
- Joined: Wed Jan 26, 2005 8:53 pm
Re: 5 speed better or worse for a turbo engine.
I live in Florida. Dead flat here.
- woodsbuggy1
- Posts: 820
- Joined: Sun Feb 20, 2011 5:15 pm
Re: 5 speed better or worse for a turbo engine.
Indiana is flatland too. The first time my buddy from Kentucky came up visit he said "If your dog runs away you can watch it for 3 days" . I guess that why we go south and east to climb hills.
Kenric
Kenric
Good quality is getting harder and harder to find.