Backwoods Supercharger

Turbos? Superchargers? Step this way...
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Re: Backwoods Supercharger

Post by Pensive » Wed Apr 18, 2018 10:18 pm

They’re a wierd kind of bearing, you can’t really tell if they’re ok without inserting the rotors. Then the only test you can do is what you see in the video

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Re: Backwoods Supercharger

Post by PeteH » Wed Apr 18, 2018 11:02 pm

I have no specific knowledge. Is that end float you are generating? If you push the end gears in and out can you generate any end float? If you can then you can put a dial gauge on it and measure how much. I assume there must be an acceptable limit on the amount of end float, which you must be able to find somewhere.
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Re: Backwoods Supercharger

Post by Pensive » Thu Apr 19, 2018 12:14 am

I can’t move the End gears in and out at all.

Little concerned that the metallic sound might be a worn spindle where the gear rotor bearings mount allowing play, but surely this would result in slight play in the cogs... and I don’t teally have much if any.

Re:end float - One rotor barely moves, the other only moves a tiny bit, I can just fit a Stanley blade in the gap at the needle bearing end.

I’m not concerned about any of the play, just wondering why there is the metallic sound as it spins and if it’s normal.

Watching this video it sounds like it should be silent?

https://youtu.be/Xx5iZHTkeco


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Re: Backwoods Supercharger

Post by 350matt » Thu Apr 19, 2018 10:52 pm

Hello

I'd say the rear rotor bearing on 1 or both rotors is worn as there should be virtually nil vertical play and that 'clinking' sound when you turn it over is the rotors touching each other

I've never known the gears to wear , the plastic or rubber couplers often break up though which also creates a racket

so I'd say you will have to replace the rear bearings with new parts

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Re: Backwoods Supercharger

Post by Pensive » Thu Apr 19, 2018 11:39 pm

yrah that what I was thinking. Mainly because I can do that first without removing the cogs because I really don’t fancy that. Trying to get them back on right is going to be very hard :-/

I’ll buy a needle bearing kit with some of that freaky blue grease :D

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Re: Backwoods Supercharger

Post by Pensive » Fri Apr 20, 2018 11:21 am

ORdered this kit from powerhouse uk:

https://www.ebay.co.uk/itm/151686324126

Doesn't include the coupler but does include snout bearings if i need them. I'll get a fixed coupler if I'm pleased with the needle bearing replacement. The genuine eaton coupler has a spring mount in it, which looks like it might damp the rattle. The fixed coupler transfers any variance in idle from the flywheel directly into the rotors without damping so can cause rattle in some cases. It's usually this spring that fails in the couplers. But the genuine couplers are £60-odd and the fixed are £30. At this point, I'm probably better going for the damped one. In for a penny in for a pound right? Total charger budget so far is £393 so another £60 means refurbished supercharger and outlet / inlet adapters is going to run me about £450 which is still on budget.

I asked them if I could get away with the Oven->Housing freezer->bearing trick for the needle bearings and he said he'd never tried it. He recommended using a press. I have a mate in bournemouth who has a garage some I'm sure he'll have one I can use in exchange for beers and giggles.

I'm in two minds about the snout. There's no play at all and If i'm going to reuse the existing pulley (which is wider than the pettit pulleys I have) I don't really need to pull the pulley off it at all. But powerhouse recommended I should change the oil seal, which means removing the pulley and punching the snout out as far as I can see.

We'll see.

___________________________________________

In other news Ryan sent me my 3 Pettit pulleys (I can only really use 2 of them - otherwise my boost will be too low). It's interesting to note that these are a rib thinner than the stock Jag pulleys. If I used a RRP upgraded pulley set I'd be plug and play with the pulley that came with the supercharger which, I think, says a lot about the choice of belt width Pettit made. However, we'll see how we go for now.

I'm not sure it's responsible to use a wider pulley on the charger, than on the crank, as this will allow the belt to walk off the crank - so I'll probably have to change the pulley anyway (and thats if it's the right size, although I don't think i can go much smaller!). But if it's the right size it might make more sense to actually buy the pulley set from RRP and run the wider belt solution.

The irony is the snout pulley I have is a little smaller than the pettit 6 psi one, which I think would actually put me around 6 to 8 psi with the pettit crank pulley (given the lower cc/rotation of the m90). I need to do the maths later on - now i can measure all the pulleys.

There's is of course a big cost implication there, which puts me at risk of busting my budget but I'm not going to to totally bodge it over £300-odd.

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Re: Backwoods Supercharger

Post by 350matt » Fri Apr 20, 2018 1:06 pm

Bear in mind the extra width / ribs on the Jag snout pulley will be to run it 1.2 bar of boost

as you're going for a half of that you should be fie to drop a rib or so off the drive belt

also couplers with springs etc are there to damp out variations in belt speed due to firing intervals
I've used the M90 on a 6 cylinder ( roughly equivalent to the 13B) and it was debatable if the sprung coupler did very much other than melt its rubbers....
I'd have no qualms about using the fixed coupler drive on this one

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Re: Backwoods Supercharger

Post by Pensive » Fri Apr 20, 2018 2:10 pm

350matt wrote:Bear in mind the extra width / ribs on the Jag snout pulley will be to run it 1.2 bar of boost

as you're going for a half of that you should be fie to drop a rib or so off the drive belt

also couplers with springs etc are there to damp out variations in belt speed due to firing intervals
I've used the M90 on a 6 cylinder ( roughly equivalent to the 13B) and it was debatable if the sprung coupler did very much other than melt its rubbers....
I'd have no qualms about using the fixed coupler drive on this one

Fair enough.

The jag crank pulley is a beast!

Here they are side by side.

Image

Due to perspective the charger pulleys look similar but the pettit one is a fair bit bigger.

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Re: Backwoods Supercharger

Post by Pensive » Wed Apr 25, 2018 9:59 am

Quick question re: cat - vote below!! :)
1) retain stock cat, as it won't impede the output as much as people say it does.
2) cat delete
3) sport cat is best, as you can tune it to pass the mot and perform well under load.

None of this is in my budget at present and i currently have stock mazda OEM cat.

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Re: Backwoods Supercharger

Post by PeteH » Wed Apr 25, 2018 11:19 am

Your limitation is going to be how well you can remove the exhaust gasses from the engine. That will determine the maximum boost you can run while keeping it reliable. A free flowing exhaust will massively help. The better your whole exhaust system, the better your power, and the better your reliability.
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Re: Backwoods Supercharger

Post by Rotary Potato » Wed Apr 25, 2018 11:23 am

2.

Why create a problem when one doesn't need to exist?
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Re: Backwoods Supercharger

Post by Pensive » Wed Apr 25, 2018 11:37 am

PeteH wrote:
Wed Apr 25, 2018 11:19 am
Your limitation is going to be how well you can remove the exhaust gasses from the engine. That will determine the maximum boost you can run while keeping it reliable. A free flowing exhaust will massively help. The better your whole exhaust system, the better your power, and the better your reliability.
Fair enough. Decat is also the cheapest option offering the best performance. So I guess I’ll do that :)

Plus : FLAMES. :D

I’ll add it to the budget.

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Re: Backwoods Supercharger

Post by Lemon » Wed Apr 25, 2018 1:21 pm

just get a mallet and an iron bar.
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Re: Backwoods Supercharger

Post by 350matt » Wed Apr 25, 2018 5:36 pm

If you have a good working Cat I'd put it to one side for MOT times

there are usually plenty of ghetto decats on here or on the 'bay ' for a small sum

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Re: Backwoods Supercharger

Post by Pensive » Wed Apr 25, 2018 6:57 pm

350matt wrote:If you have a good working Cat I'd put it to one side for MOT times

there are usually plenty of ghetto decats on here or on the 'bay ' for a small sum
Exactly my thinking.

I’ll buy a gutted one or a dead one and have at it. I have a “persuader” mallet.


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Re: Backwoods Supercharger

Post by wiggles » Wed Apr 25, 2018 8:40 pm

I'm very interested in this project as I'm sure are a few others so when it comes to getting the supercharger mount made up maybe a few of us could buy one to bring the costs down? I know we don't know if it works yet.... But can't see why not
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Re: Backwoods Supercharger

Post by Pensive » Wed Apr 25, 2018 9:04 pm

The thought did cross my mind; I'm hoping to get a batch of custom parts made up once I've got a prototype - but that's down the road.

There is another guy who messaged me also interested in getting involved - maybe a few cavalier souls might be willing to experiment financially once I've got a working prototype. It might allow me to over-flow my budget a little to get the project over the line.

Not sure I would want to offer a full DIY kit as such but I'd be happy to "enable" the cheaper project as best I could. With this in mind it's almost a shame I went for an M90 rather than an M112. But to be fair I havent fixed the M90 yet - it may yet be a dog.

As far as I can tell so far a basic kit would need:
1) Supercharger mount plate adaptor with pre tensioner attachment
2) custom pipework from charger to engine inlet with MAP sensor (boost side). (possible mod to existing inlet. not sure yet. one step at a time)
3) RRP pulley set for pettit supercharger (or nudge ryan to ask who bought his upgrade kit as they might have the old bits lying around....)
4) charge cooler (for use with any intercooler / coolant bottle / pump /mounting solution you wish)
5) custom pipework from charger inlet (cold air side) to off the shelf aftermarket air intake.
6) relocate plate where the airbox used to sit, for the relocation of injectors (I'm assuming this will be necessary).
7) relocate kit for the oil filler. (I'm assuming this will be necessary).
8) Diverter valve and adjustable boost limiter. (but this could be to preference really - you could go cheap and cheerful or go mappable electronic).

the only really challenging parts of this are 1), 2) and 5) - the rest is actually a number of fairly simple smaller elements.

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Re: Backwoods Supercharger

Post by 350matt » Wed Apr 25, 2018 10:59 pm

Thats a good list, 1 thing missing though is the ECU modifications to the map and possibly to the wiring loom?

I'm assuming mazda edit can cope with running the engine in a forced induction mode rather than NA and the current baro sensor socket can be re purposed to plug in a MAP sensor . If you were to use one of those combined P & T sensors by bosch this would also give you a air temp input post chargecooler.

then you woudl need to modify the MAF sensor wiring so the temp sensor input now comes from the MAP sensor

also I don't know why you need an adjustable boost limiter? Chargers will make the boost that they are spun at. might be a useful gizmo when setting it all up but otherwise all you need is the original diverter valve to prevent the charger stalling on the over-run

also I don't see why you need to move injectors? as surely you leave the metal part of the manifold alone and make your new adaptor to replace the current plastic portion?

or did you mean to move the coils ?

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Re: Backwoods Supercharger

Post by Pensive » Wed Apr 25, 2018 11:04 pm

I meant move the coils!! :D bit tired.....

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Re: Backwoods Supercharger

Post by Pensive » Wed Apr 25, 2018 11:05 pm

I did a little video :D

https://youtu.be/ifLz6eCiw74

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Re: Backwoods Supercharger

Post by PeteH » Wed Apr 25, 2018 11:31 pm

Nice vid. If you measure the hole size in the casting at either end of the needle roller bearings, you may find that one end is smaller than the other, indicating a seat for the bearing, and informing you which way to press them out. I'd be surprised if there wasn't a seat, because their position should be closely controlled. I'd also be surprised if you can hammer them out.
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Re: Backwoods Supercharger

Post by 350matt » Thu Apr 26, 2018 9:45 pm

Have you seen this?




looks a little different to your unit though

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Re: Backwoods Supercharger

Post by Pensive » Thu Apr 26, 2018 9:52 pm

Yup, that’s why I’m punching them out in the direction I am. I can’t get my Calipers to measure the width properly and I long ago threw away my cartography compass. :-/

I don’t want to push in the wrong direction. I’m going to call powerhouse since they sold me the bearings and they were very helpful..,


I’ll

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Re: Backwoods Supercharger

Post by 350matt » Sun Apr 29, 2018 10:00 pm

Just doing a bit of casual surfing

and wasn't aware that this BLitz SC kit existed?

http://www.turbosport.co.uk/showthread.php?t=1215550

Car is still on the road , well has an MOT
any one on here?

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Re: Backwoods Supercharger

Post by Pensive » Sun Apr 29, 2018 10:41 pm

I’d heard of it before but don’t think they sold too well in the uk - haven’t seen anyone say they have a blitz kit (I’m sure there are a few).

I sent an email to Pettit asking if they have any inlet manifolds available in case they have something on the shelf; however my fall back plan is to reverse the boost side tube and route a pipe for the diverter valve, which would allow me to re use the standard inlet manifold using off the shelf piping

This risks a slightly poorer air flow but means I won’t need to relocate the oil filler. Considering this option for cost reasons.

Would just need to drill in a MAP sensor.

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