What would you do?

spuddy

spuddy

Ulster Area Rep.
As I'm sure some of you know I have suffered my first gearbox explosion. I'll get some pics up in the coming days, it's not pritty what goes on in a box when a gear goes bang!

This small hiccup has got me thinking, if I continue to drag the car there will be alot more gearbox failures, it's unrealistic to think 405flbs torque is going to pass easily through a standard GT box without breaking.

So how many times can you replace a box and due to not knowing fully the history of that box, you have to replace bearings, syncros and seals (or maybe thats just me) before it becomes un economical.

I have been looking to buy and MR2 and mod it up to a decent spec in or around 600hp. This is going to cost a fair bit.

I've started to think since I have a GT already running 400+hp I could put a little extra into it and make it more durable and competative.

Instead of going down the MR2 route I could fit the GT with a dogbox both for strength and the ability to flat shift which would improve my ETs. I could also outfit the car with a full light weight bodykit (Boot, Bonnet, Wings, Doors and Windows). I could also fit smaller front brakes so I can run 13" rims with full drag slicks, a proper inlet and ignition system combined with a standalone ECU.

There are alot of Honda Turbo builds appearing over here but I'm thinking so long as the Irish drag scene maintaines a Turbo class under 1600cc then I could possibly dominate it. I think with a similalre setup to what I'm running I could knock on the door of 500hp.

So anyway, let me know what you guys would do.
 
Starlet_Sam

Starlet_Sam

Moderator, Regional Area Reps Supervisor & Gay Car
Why use an MR2 which competitively would be mediocre with 600bhp when you could have a car that wins it's class?
 
Jay

Jay

Admin
It sounds like you already know the answer mate.

Someone has to step up to the plate and take an EP to the next level.

Push the envelope a little. ;)
 
Brendanlez

Brendanlez

Member +
There is a crowd over beside Limavady, who might help you out with some information, Limavady Gear Company. They do some gear machining for our company, and as far as I can recall the have built some rally gearboxes for the likes of Evo 8's. Maybe if you have a talk with them they might be able to help you with the dog box.
 
spuddy

spuddy

Ulster Area Rep.
Brendanlez said:
There is a crowd over beside Limavady, who might help you out with some information, Limavady Gear Company. They do some gear machining for our company, and as far as I can recall the have built some rally gearboxes for the likes of Evo 8's. Maybe if you have a talk with them they might be able to help you with the dog box.
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Hmm interesting! I'll have to get in contact with them and see what they think.

It is a fair bit of money but sure what else would I do with it :p
 
Texx

Texx

Super Moderator
How did your last box fail? Did it strip the teeth off of a gear?

There's no doubt a straight cut gear set will be able to handle a lot more power and torque than the stock helical cut gears, but fitting an expensive straight cut gear set could expose other weaknesses in the transmission. Is there any signs that the transmission case twisted or either shaft bent or distorted under load? I'd be asking and trying to answer as many obscure questions as I could before investing a significant amount of money into a gear set only to then install it into an assembly that is not up to the job.

Are there any other cars using a C52 or equivalent box that output similar or more power and torque figures as yours and are used for drag racing?
 
spuddy

spuddy

Ulster Area Rep.
Both gears from 3rd are completly stripped bare, well all but 2 of the teeth are uncrecognisable, I have the entire box stripped, next time I'm down where its being fixed I'll take alot of pics.

The casing itself did appear to have a crack in it. The shafts themselves I'm not sure if they have twisted, how would you tell?

I'm not sure if anyone else is running as much torque though one of these boxes. However there is a possible reason for the failure. The slave cylinder was knackered and when the box let go I had difficulty getting her into second gear on a run, then shifted to 3rd and it was difficult to get in and boom, gearbox gone.

Maybe the Slave cylinder wasn't able to cope any longer.
 
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Iain@CRD

Iain@CRD

Lifer
This is my opinion Spuddy.

You have a very competative GT and one of the quickest in Ireland also, if you changed to something like an MR2 with 600hp that wont be as competative or fighting for the "lead" as much as the Starlet would be.

There loads of high powered RWD cars and im sure theres a few in Ireland but rarely do you a FWD GT with the power you have.

If you dogbox it you wont regret it.
 
billybob

billybob

Untrusted Seller
Iain@CRD said:
This is my opinion Spuddy.

You have a very competative GT and one of the quickest in Ireland also, if you changed to something like an MR2 with 600hp that wont be as competative or fighting for the "lead" as much as the Starlet would be.

There loads of high powered RWD cars and im sure theres a few in Ireland but rarely do you a FWD GT with the power you have.

If you dogbox it you wont regret it.
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x2 .stick with the starlet lad for awhile you have to run a low12s with your car or 11s you can do it your nearly there ..no good given up on it yet :rockon:sure the seson is only started hopefully il have mine done for the next one 5e all the way:)
 
M

madmanGT

Banned
abit of topic here guy's but whats your inputs on this tubby! i am now thinking of getting into the drag scene and was thinking something along the lines of this,ovbiously on a forged engine
Picture515.jpg
 
Texx

Texx

Super Moderator
spuddy said:
Both gears from 3rd are completly stripped bare, well all but 2 of the teeth are uncrecognisable, I have the entire box stripped, next time I'm down where its being fixed I'll take alot of pics.

The casing itself did appear to have a crack in it. The shafts themselves I'm not sure if they have twisted, how would you tell?

I'm not sure if anyone else is running as much torque though one of these boxes. However there is a possible reason for the failure. The slave cylinder was knackered and when the box let go I had difficulty getting her into second gear on a run, then shifted to 3rd and it was difficult to get in and boom, gearbox gone.

Maybe the Slave cylinder wasn't able to cope any longer.
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I'd be interested to see some photos. Are both 2nd and 3rd gear synchos still in one piece or did they get chewed up at the same time?

You can check the run out of the input and output shafts in a similar way your would for a camshaft. Support both ends of the shaft using a pair of V blocks and then measure the run out with a dial gauge.

What's all this 'dog box' lark people are talking about?

Is this referring to dog engagement instead of using synchro rings?
Or is this referring to straight cut gears instead of using helical cut gears?
Or a sequential shift set up instead of a H shift pattern?

If your going to upgrade then straight cut gears with dog engagement are the obvious choice. But as I said above, I'd want to be as certain as possible that the C52 casing and shafts are actually capable of retaining and transferring the amount of power and torque your engine will throw at them. It's all well and good fitting nice strong shiny gears in there, but it'll be a waste of money if one of the shafts can't cope or the case cracks open and throws the input shaft out the side of it.

It may be worth looking at what's being used with big power turbo'd 4/7A-GE's, if C52/C56 box's are being retained then knowing any common problems or weaknesses will be of benefit.
 
billybob

billybob

Untrusted Seller
Iain@CRD said:
This is my opinion Spuddy.

You have a very competative GT and one of the quickest in Ireland also, if you changed to something like an MR2 with 600hp that wont be as competative or fighting for the "lead" as much as the Starlet would be.

There loads of high powered RWD cars and im sure theres a few in Ireland but rarely do you a FWD GT with the power you have.

If you dogbox it you wont regret it.
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id say he has the quickest gt in Ireland sure its a great setup he has there defo 11s in this or better than a 12.9 easy :)but teds is nice a quick too :)a glanza gearbox with a nice lsd will do it
 
spuddy

spuddy

Ulster Area Rep.
Yea Tex, by dog box I mean straight cut gears with dog engagement.

I havn't had a look at the syncros yet, I have ordered new ones as a precaution though. I would be surprised if they havn't suffered damage, the amount of metal fragments in the box was insaine. They were all brand new syncros fitted about 6 months ago.

@Madman, thats a big looking turbo, which of the VF series is it?
 
sacodetoro

sacodetoro

Lifer
If it were me, before i got a expensive custom gearbox I reduce the power/torque slightly so a stock box could cope and then go with the smaller rolling circumference wheels and very lightweight body panels. I think you will see greater gains time wyse by doing that rather then having 50 bhp more.

The solution to your problem isn't to throw money at it right away. I'm not saying don't get one in the end I would just do that first
 
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