Need pics or suggestions on how to build or buy a 1 st gear lockout.
GB
Remove the gear and leave the bearing race in place. Put everything back together.
The shifter will still be able to go for first... but you wont find anything. If you truly want the shifter to not even go near first.. then make a small alum clamp for the shift shaft that stops it from moving forward in the case.
I dont have any pics on this computer. It is very simple.
B
If you put a clamp on the shift shaft, won't that stop you from getting into 3rd and 5th also?
Maybe this is more what your thinking
Attached image(s)
There are 3 shafts. One for 1st/R one for 2/3 and one for 4/5
All you have to do is stop what would be the forward motion of the of the shift shaft. Just the distance that the slider would need to engage the 1st gear dog teeth. Leave the slider on the pinion shaft (if you want to keep reverse) and remove the actual "driven" gear from the pinion shaft. The drive gear for first needs to stay in place.
I dont know what the actual term is that the 1st/reverse slider slides on, but 1st gear sits on it also.
B
KenH has a nice set-up on his. It allows you to keep out of 1st and reverse when needed. You remove the lock-out bar and you can do as you please.
KT
Ha ha.. I thought you wanted it GONE!!!
Sorry..
What I described above is for the V8 conversion guy's..LOL
Increase the spring pressure for 1/R and forget about it.
B
I just installed a 915 shifter I got from Seine Systems that was modified, adding a spring for 1st/rev to keep the shifter in the 2/3 slot unless you push pretty hard towards 1st/rev. I had to cut the ball off of the 915 shifter and weld the eyelet from the 914 shifter on the bottom, but I must say, it's the best shifting 914 I've ever driven, and it's not easy to accidentally get it into 1st. You can see it here- http://seinesystems.com/GateShift-901.htm
I also welded the tab on the left, after all adjustments, so I could remove the hose clamp that you see in the pics.
I had 3-4 failures from this exact "conversion" the welds broke every time. I had a certified welder do it after my first one broke.. For some reason that metal doesnt like to be welded!
Good luck!!
B
I figured it out: dont shift in the corner!!
Actually very few people have a car that can "lift throttle" and make an upshift in a corner without losing it...
B
Pictures
Never finished the drawing, but you get the idea.
Material is 1/4 steel angle.
Had a guy that fabs steel make it for me.
Ken
Attached thumbnail(s)
Attached image(s)
my rennshift basically alleviates any of the missed shift concerns.....
even while under 1.2-1.4 lateral g-loads? i never thought it was an issue with the shifter...
Trek..
I think Kens is MUCH cleaner that some of the others posted, but a MUCH simpler solution was shown in the main forum.
My concern here:
If you get hit from the side.. your right leg has to get passed the shifter somehow. The stock stick will break.. this wont.
Through my years I have met two people involved with side impact wrecks in their 914's. Both walk with a limp after wiping out the shifter with their right knee.
Look at the other solution. It is VERY stupid simple and does not get in the way of anything.
B
http://www.914world.com/bbs2/index.php?showtopic=62225&hl=1%20st%20gear%20lock&st=0
Attached image(s)
This is a store bought item tig welded to a block of aluminum and bolted to an existing threaded hole in the tub. It will also work with ANY shifter you install in the car.
B
I like it. I'm going to build one, unless a couple guys want to negotiate a lower price for a few units I'm willing to go along. I damaged my trans last month at Laguna Seca doing the 5 - 4 - 3 downshift coming into two, I caught 1st for 1/2 second. It was enough to make my trans start acting weird. 1st and reverse work but I have to double clutch to get into 5th. It's the last time that's going to happen.
The Rennshift doesnt solve it. I *thought* it did, but I experienced it myself a few events back in 914 2.0 car at an AutoX.
VERY fast right hand turn that I needed to upshift into third at the apex of the corner. I caught first.
This may sound *crazy* but the actual weight of your arm may effect how much the shifter is going to move in a high G corner. You have your hand on the shift knob and your arm is trying to go across your body pulling on the shift lever. I was in a stock seat with the lower cushion out.
B
Brad,
I agree,the best and safest lockout seems to be the plunger style with the red ball. The Rennshift is defintely a quality product but it does not fully lockout 1 st gear, it uses spring tension to accoplish this. Others members using the Rennshift have commented that they are going to stiffer springs to safe guard this happening. I've tried to source this piece at local tool suppliers with no results. Where can it be found? Any leads?
James will supply you with the correct stronger springs.
I guess I'm lucky...
but I've never had a first gear situation on the track
I don't autox though....
brant
Brant,
I think he is referring to the lockout/red knob thingy above??
I would imagine this is a "McMaster Carr" item.
Brant,
you are also correct.. AutoX transitions are MUCH more harsh than road course transitions. I can easily see why this is an issue in AutoX but hasnt really been seen in road racing.
B
oops..
I re-read the post.
your right, he is asking about the custom lock out and not the springs.
(regarding the rennshift... when I had one, I know James was kind enough to give me the stronger springs as they became available.)
Brad good eye, yep McMaster Car.
Search Weld-in Pin not bad priced either. Might have to recess it a little, or extend the shaft 5/8th is not a lot to play with. They also have a T-handle model, which would be easier to grab with gloves on.
Attached thumbnail(s)
Beleive it or not.. I actually do get involved with race car builds..LOL I dont just talk about it
Based on his alum block.. they probably extended the shaft. The shift rod is VERY close to the tunnel right there.. maybe they didnt have to??
For that price, buy one and find out
B
All these items being discussed will do no good for shifting a car in a high lateral G situation.
The problem is that the trans is changing its location related to the shifter. Even if you had a robot shifting the exact same spot the shifter you would still miss, because the engagment slots in the trans have moved to a different spot than when the car is unloaded. This includes anything done in the cockpit of the car like the linkage blocking pin. The back part of the chassis twists and now 1st gear is in the position of 3rd as the linkage up forward sees it. The RennShift does all that can be done in addressing the issue up front - by having gate springs you allow the shifter to find the 3rd gear slot as you pass through neutral and do not put any side load on the shift knob. You can't do any better than this at the forward end of the linkage.
I could easily build in a solid lockout device in place of the rev/1st spring in the RennShift, but it would be false security and would not solve the issue. The reverse lockout does work for upshifting, but that is a different dynamic situation.
The only way to fix this situation is to stiffen the chassis (assuming the mounts have already been replaced with solid if you are experiencing this issue). You are only going to go so far with that, so eventually it becomes something you just have to drive or change gear ratios around.
Roll cage
Solid engine mounts
Solid tranny mounts
And.. really light springs with a stock sway bar on not really sticky tires
No rust chassis
Still think this wont help?
Two other cars with the same issue.. full cages.. solid mounts and tranny mounts tied into the cage.
I beleive there is *some* movement, but come on ?? really ??
B
Ha ha..
Half the cars have bad tranny mounts!!..LOL
B
"If it is stiff enough, then the RennShift or these lockouts will do the job. But a lot of the cars in this thread are going to encounter this issue even with the blocking pins installed."
James, I got a solution, build a RennShift cable shifter for the 901. That takes the mechanical movement out of the picture. That is unless you mount the cable in a way that if causes stress and pulls the inner cable.
I know there has been a couple of home grown version, but a good quality kit might sell, then again it might not recoup the investment in engineering time.
Just Ideas.
Ah crap I just came back to a Boxster Trannie installation.
Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)