SR20 / Sr20det to RB25 gearbox conversion plate s14 s15

[fry]

What you will get for your money is the conversion plate and all the nuts and bolts to fix the RB25 box to your SR20.

Only slight other modifications needed to do the conversion and any DIY mechanic can do it.

Takes only a short while longer to do than a normal gearbox/clutch swap.



The plate

Is made from 6mm thick steel, it is 1st laser cut, then the second stage is the CNC machine, all the studs are tig welded in, it is then acid dipped and Zink plated before all the dowels are pressed in. Made to the highest of standards using the best possible materials, machines and knowledge i know of. Also has been through extreme testing in my car(polo) running 465hp and 405ftlb torque, so no need to worry about quality, rust or breakages.



Prices
up to 9 plates, members pay £295, non members £320
10 plates or more, members pay £250, non members £270.


I now hand you over to Polo

[Polo2]

Thanks Fry

Any Q's please ask here and il do my best to answer in as much detail as i poss can.

Here is a bit more info on the plates.

FAQ's

"Will my standard sr clutch work with the conversion?"

Yes, any clutch and flywheel combo for the sr will work fine with the conversion. I am using the exeedy twin hyper clutch.

"Will the input shaft locate into the spigot bearing enough with the 6mm plate?"

Yes, the standard plate that is between the engine and box is 2mm thick, this is 6mm thick so its effectively only 4mm also the input shaft on the rb25 box is longer, so you will actually get more location than with the sr box. You can create more location if you wish by fitting a new spigot bearing, by putting it in so its flush with the crank rather than below flush, how they are as stock.

"Is there any machining that needs doing to the box or any thing else?"

No, none at all! Its near on a bolt on kit.

"What else do i need to do the conversion?"

All you will need is,

- rb25 box

- rb25 prop

- rb25 gear stick/shifter

- rb25 clutch slave cylinder

- rb25/r33 manual or s14 auto gearbox cross member

- And one of these plates of course

- Its recommended that you fit a new spigot bearing

"What other modifications do i need to do?"

- The transmission tunnel needs slight modification

- The rb25 prop needs to be shortened (you don't need to get a sr prop mated to the rb25 prop as the rear flange is the same) there are places that can do this for as little as £50.

- The starter motor threaded holes need to be drilled out to 12mm, as with the conversion it is held in place with studs. Also, depending on what age the starter, you may need to shave a slight bit off of the location lip (s14a late and s15 only)

- There is one threaded hole in the box that also needs to be drilled out.

- The gear stick/shifter sits 6cm more foreword than the sr box, so the hole the stick/shifter comes through in the body needs to be made slightly bigger.

Once you have done that lot it really is just bolt on.

The s14 auto or r33 manual gearbox cross member mounts straight up to the body and box using a standard mount, so no need for a custom box mount!

The rb25 slave mates straight to the s14 hose!



This is all based on a s14 body, there is no reason it wont work on any other body,

Il have full detailed pics of step by step fitting up in a few days.

[Aj82]

Very interested in one of these. Looking forward to pics. How do you know how much to shortern the prop by?


Cheers Aj

[Polo2]

Very interested in one of these. Looking forward to pics. How do you know how much to shortern the prop by?


Cheers Aj

Iv got all the mesurments for s14 and s15 Im yet to fit one to an s13 body to get the mesurments for one. There are 20 of these plates fitted to cars all over the world already with no reported problems. I know at least two of them are in s13's and two are in s15's, all the ones iv fitted so far have been in s14's.

Il start a list once iv got a few people who are 100% commited.
I dont need to take a deposit but im leaning towords taking one to avoid time waisters.

[Polo2]

Iv just had a word with the people i use to make the props, we have come up with a system where you will just have to quote a Ref No or name (yet to be desided) so you dont have to get involved with mesuring etc.
Iv just had one done this week and it was £71.50 posted

[Aj82]

Superb!! IM intersted so will be watching this thread.


Cheers Aj

[danb]

what are the boxes rated too?? i know you said your running 465 through it, but can they take more? or are you maxing it out as it is?? also the £71.50 is that us sendign the prop to them, they doing the work and sending it back - or them supplying the prop aswell??

[STR8E180]

there is a pretty good thread on hardtuned.net comparing all the RB25 gearbox adapter kits for SR20's so it might be worth checking out if ur in the market one for

http://hardtuned.net/forums/index.php?showtopic=400980

[Polo2]

what are the boxes rated too?? i know you said your running 465 through it, but can they take more? or are you maxing it out as it is?? also the £71.50 is that us sendign the prop to them, they doing the work and sending it back - or them supplying the prop aswell??

Thats buying the prop and sending it to them

Tbh, i dont know how much the ratio's effected things as i changed the diff ratio at the same time, they are quite long i think, id recomend changing to a 4.1:1 diff ratio.

[danb]

also what about the speedo sensor?? what happens to that?

[Polo2]

also what about the speedo sensor?? what happens to that?

If you wire the RB speedo in you will get double the speed reading Iv got some one making a relay bored to bring it back to normal. They wont be included but wont be expensive, around the £20 mark

[danb]

If you wire the RB speedo in you will get double the speed reading Iv got some one making a relay bored to bring it back to normal. They wont be included but wont be expensive, around the £20 mark

great - sorry for all questions - want to make sure ive got all bases covered before committing.

25 box is out of all gts-ts aint they??

[Polo2]

great - sorry for all questions - want to make sure ive got all bases covered before committing.

25 box is out of all gts-ts aint they??

Yep, r33 GTSt Can pick the box's up any where tween £200-£450, you will also need the slave, prop, cross member and shifter from the same car, normaly an extra £100 for the other bits

[Robdriftit]

please keep this to the conversion plates

[Random Tim]

Been down to see Polo today to have my plate and gearbox fitted and took lots of pics. Here are a few so you can see how it all works.

The Plate


RB25 Box


RB25 Box next to SR20 Box. RB at back


Plate Fitted




Cut out in tunnel for shifter


RB25 and SR20 Props, RB at bottom


Box fitted up and ready to go


I have afew more pics on Photobucket if you want to see any more of whats involved in the conversion.

Thanks for today Paul, the car drives fantastic with this box

[danb]

awesome - ill deffo be going ahead with this - especially if we can get 10

[Polo2]

Cheers for sorting the pic Tim

You forgot to mention the great news with the shifter and speedo

We got the speedo reading basicly exactly how it should! with in 5-10mph Tim? I think with the shorter diff ratio it will be spot on

We got the shifter in as near on stock posision as poss and all works well with the stock gator

[Polo2]

Here are some of Tims pics of the shifter i made for him. Not perfect but a step in the right direction. A few slight tweeks on the mesurments of the shifter and it will be spot on.

Universal CV boot to stop oil splash

1st gear

Neutral

2nd gear

[Random Tim]

I did forget that yeah
The shifter feels fine to use in that position but like we said, it wont take much to get it perfect, that wasnt a bad guess for the position.
And the speedo reads within 5mph of polos beemer to over the speed limit.
The ratios feel fine on the road. Maybe a little long in 5th when at low speeds. I think when the power goes up to around 300 it will be fine

[Polo2]

Right, iv had a few people question the price and how iv come to what there up for. So, i feel i need to explane exactly what goes into making these plates and why they cost what they do. (which IMO is still bloody cheap, with out a doubt the cheapest option out there)

Julian at garageD is my main customer and has had over 50% of the plates iv had made so far. Also, iv sold a few to customers over in OZ,(at full price £350+£80 postage + tax/duty) none of them questioned the price atal once they see the quallity and understood exactly what is involved in them.
If this goes up to 10 plates you lot will be getting them at a bargain of a price!

Iv made these to help fellow sbody owners not to make money but im not doing it for free, as im sure you can understand takes alot of my time getting them produced.

So this is where the money goes,

To start with, i had to pay some one to sit down and do the drawings. This involved lots of running backwords and forwords, test fitting, mesuring, jigging, etc etc, That lot took place over 3-4months. Drawings and mucking around like that done come cheap.

Next was to buy in the materials for the jig and have the jig made. If any one has bought a block off alloy approx 2ftx2ft and a few inchs thick will know that aint cheap either. Again, making the jig its self is not just 5mins or a few hours, its a few days.

Then the guy im using to do all the drawings and basicly make the plates for me, had to buy in the tools to make them(tools and bits dont last for ever and need replacing, i.e the bigger counter sunk bolt hole cutting bit will only cut enough holes for 20 plates befor its useless)

The next stage was/is to order the sheet metal for the plate and get it lasor cut. Sheet metal tollerances are poor! i.e 6mm plate can be from 5.1mm-6.9mm! We have to make sure the sheet we get is exactly 6mm.

Once the plates are back from the lasor cutters, they are loaded one by one into the CNC machine, the machine does one side at a time. So for 20 plates the oporator has to attach a plate to the jig 40 times. Each plate spends a good period of time in the machine, not just 5mins.

Once the plates are out of the CNC machine, the studs all need TIG welding in, again a time consuming process. 8 studs per plate and you can only do one at a time, this is to stop the plate from distorting from the heat. So one stud is welded into each plate, then the second into each plate and so on.

Once all the studs are weded in, the pllates are acid bathed and zink plated.

Out of all the bolts to hold the plate to the engine there are 4x m12 counter sunk bolts. These need turning down on the lave one by one. (80x for 20 plates, takes a very long time)

On each plate there is one dowl that is screwed onto one of the studs, these are made one by one on the lave.

There are 3 other dowls in each plate, there not a standard size, so each one of them has to be milled down, one by one. I have to buy these in befor there milled down.

Then there is the cost of all the other nuts, bolts and washers.

Some of the costs above are obv one off's like the jig and the drawings, that has been spread over the first 40 plates. After the first 40 i will be able to lower the price more.

Now, hopefully you can understand how much time and effort these take to make and have a little more understanding of the cost.