Non-syncromesh with helical teeth?
- Thread starter croc
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Albins. See Dave Deersons photos, post #306 on http://www.gt40s.com/forum/gt40-build-logs/16138-kiwi-scratchbuilt-11.html#post267414
Yup, Albins..............I did want straight cut gears at first. You know, I felt that for all the money I spent on regearing the box that I wanted everyone to hear/know how I spent my money!!!
I, however caved in to reason when they(Albins) stressed that a low angle helical gear is actually stronger then a straight cut gear and the difference in friction is too slight to notice in my application.
I, however caved in to reason when they(Albins) stressed that a low angle helical gear is actually stronger then a straight cut gear and the difference in friction is too slight to notice in my application.
Someone please correct me if I'm wrong; but i always thought, even though a straight cut gear is weaker than a helical gear, they don't put the thrust loads on the case. And because of that, they they can increase the horse power capacity of a box?
I did a lot of research before plunking down any $$$, and as far as I know, Albins is the only maker of dog change gears for a 930 gearbox. As far as thrush loads go,I am putting an honest 410hp to the ground in a 2100lb tube frame racer with slicks,running 25 min track sessions(sometimes back to back), and gearbox temp have never been an issue. In have been told that a 930 box can take upwards of 700hp. So what I ended up with is a "poor man's LG500"(even though doing up the 930 still wasn't cheap, an Lg,DG300 or DGB box will start at $20k,$10k an $15k respectfully).
Here is the breakdown of costs in my gearbox. Good usable core $2100. Limited slip(KAAZ unit) + labor to setup ring and pinion $2000. Dog0change conversion $4,000( each ratio is $890US and then dog rings/sliders and new selector shafts). I did the conversion myself, which is good that I learned, since I had the box apart a few more times due to issues that crop up. Here is a good link for going through a 930 box: A time for change….A 930 transmission gear swap ImagineAuto’s Imagine Nation Here are some tips: 1. The engine needs to be solid mounted if you're going to have a rod style gearshift as you need the drivetrain to remain stable if you shift without the clutch. If you don't, what will happen is the torquing of the engine/trans coupled with the motion of the gearshift linkage will force the shift rail into slipping in the shift fork( mine happened in 3rd).I am planning on eventually machining up some spacers for the rails so the will bottom against the case and will not let the fork over-travel. 2. You will have to grind/machine the lower rear bearing area of the case if you are going to put a taller 1st gear as there is a big casting rib that will foul a bigger gear. 3. use the chance of having the case empty to install fittings for a cooling system. *(see Russ Noble's thread for a great writeup and pics of how it's done!) Overall, it's still not an inexpensive endeavor, but like I said before, for my use (track only) this was the best compromise for the money instead of getting a Hewland DGB( I still keep my hopes up for a bargain someday!!! Dave
Dave,
Thanks for the informative post: I especially appreciate the link about the 930 trans. rebuild.
BTW, I own an '88 Lola Indycar gearbox that is DGB based. The extra wide gears look beefy, but the LSD in it(used for Indycar road races)looks positively tiny. I'm surprised that it could hold up to all that power and wide rear slicks.
Do you know by any chance how much power/torque the DGB transaxle is supposedly capable of handling?
Jack
Thanks for the informative post: I especially appreciate the link about the 930 trans. rebuild.
BTW, I own an '88 Lola Indycar gearbox that is DGB based. The extra wide gears look beefy, but the LSD in it(used for Indycar road races)looks positively tiny. I'm surprised that it could hold up to all that power and wide rear slicks.
Do you know by any chance how much power/torque the DGB transaxle is supposedly capable of handling?
Jack
Jack, I'm not really sure, but there were many GTP cars with big horsepower motors( V8 Chevies and turbo motors) that used the DGB (although some later on used the March designed case with the 2 piece final drive housing that was much stronger). Jack Ondrak has a Huffaker Fiero that now sports an ex-Indy turbo Buick V6 with 650 to 700hp through his DGB.
You make it sound as if you're not happy with 930/Albins set-up. Why's that?
As for LG500, its shaft centres was something like 115mm compared to 930's 76mm, and the LG's crown wheel was like the Chevy 12-bolt with HUGE hypoid offset. Not my cup of tea.
The nearest Hewland to the 930 is the FGC, which has the same 76mm shaft centres and about 8.5" spiral bevel crown wheel. No hypoid. The next size - the DG300 - is similar to the FGC but with 89mm shaft centres and again no hypoid BS
. However, I just wish that selector forks in Hewlands were on the input shaft though.
Ian Anderson
Lifetime Supporter
Hi Middy
Have you looked at the Elite Transmissions offerings
Elite Racing Transmissions : Homepage
They seem to offer a range of stuff and are UK based
Ian
Have you looked at the Elite Transmissions offerings
Elite Racing Transmissions : Homepage
They seem to offer a range of stuff and are UK based
Ian
Albins is a top notch gear cutter and do make good quality gears.
Albins cuts all of our off-road gearbox gears.
Those gears stand up behind 1200 hp in some cars.
You misunderstood me. Once I got everything sorted (shift linkage, fork adjustment/ retention,cooling system,etc..), I am really pleased at how it shifts.I have nothing but praise for Albins in the performance of their products and how I was treated/handled during the ordering process. The transmission/act of shifting is now "transparent" in how I don't have to think about or worry about the act of changing gears. I just long for a DGB due to the fact that it is a proper "race" transmission and most mid engined race cars of the 80's and early 90's used it. I like the ability to tinker with the gear ratios at the track. Also,it would be kind of neat tobe able to hang the rear suspension off the trans and do away with alot of weight back there( there were a few Spice-built Fieros with this setup-see pic) That's all, I guess it's just a case of wanting what we don't have!! I did have the opportunity of getting a DG300 for a very good price not too long ago, but the DG300 has the shift linkage low and on the right,whereas the DGB is high on the right(very similar to position where my 930 has it), so I would have to rework or build new headers and reconfigure much to change the shift linkage routing. The DGB also as I understand, was an improvement over the 300(many upgraded the DG300 with DGB internals and called it the DGZ). One of these days I will take the time to show a build thread of my car, but sometimes I feel like I'm afraid of the criticism, as some here have been building/racing some serious machinery much longer than me!
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In what way was the DGB different from the DG300 (besides shift linkage location)? As you probably know Hewland only did a manual for the latter.
"One of these days I will take the time to show a build thread of my car, but sometimes I feel like I'm afraid of the criticism, as some here have been building/racing some serious machinery much longer than me!<!-- google_ad_section_end --> "
If you are afraid of the possible criticism here , do you have a build thread somewhere else?
If you are afraid of the possible criticism here , do you have a build thread somewhere else?
Jeez Dave,
No-one that's been building or racing on this site is going to criticise you. We just like to see you out there doing it.
We're all petrol heads, doesn't matter that its not a 40. Just being rear engined and using the same sort of stuff we are using is enough. We share common problems, fixes and upgrades. Your inputs on my buildthread have been most informative and helpful.
Lets see your car....
No-one that's been building or racing on this site is going to criticise you. We just like to see you out there doing it.
We're all petrol heads, doesn't matter that its not a 40. Just being rear engined and using the same sort of stuff we are using is enough. We share common problems, fixes and upgrades. Your inputs on my buildthread have been most informative and helpful.
Lets see your car....
