41 replies to this topic

[starlight]

Have been looking round at getting an underdrive pulley kit for my turbo since my belt idler pulley bearing has started sounding like a squirrel...

Anyway, I've been in contact with MMG Performance and Liam is willing to sell their underdrive kit for £150 incl P&P (as opposed to £189 plus postage) if we do a group buy of 5 or more...





From the website:

Real HP & torque gains across entire RPM range.
Underdriven pulleys are a performance product that actually net additional engine torque and bhp by reducing parasitic drag caused by belt-driven accessories, but more importantly by being lighter and reducing rotational mass. This modification also allows for quicker gear changes due to the RPM being more responsive.

Free up 12-15 BHP

These are some of the best bhp improvements you can find for your money.
The kit has been designed to allow you to remove the auxiliary belt tensioner, a/c idle pulley and all of the casting they are bolted to, so in total 4.65kgs can be lost as a direct result of fitting this kit.

INCLUDED IN THE KIT:-

1X UNDERDRIVEN PULLEY
1X ADJUSTABLE ALTERNATOR BRACKET
1X BELT





All this for £150

Better than using the standard pulley and a short belt, as there will be no issues with oil pipe clearance

1. pjohn151
2.
3.
4.
5.

[kipper]

Still seems expensive, but what the hell!

[Mac vx]

After one of these too. Count me in. 1. pjohn151 2. Kipper 3. mac vx 4. 5. Let me know when we need to pay and who lol

[John Faulkner]

free up 12-15bhp!?!?!?!?!

[kipper]

free up 12-15bhp!?!?!?!?!

I do have my doubts

[starlight]

free up 12-15bhp!?!?!?!?!

I do have my doubts

Well, I don't believe you can get that kind of power increase either, at least not steady state engine speed - aux drive belt drag (excluding alternator loading) is normally in the region of around a constant 2-3Nm parasitic loss depending on belt routing and number of pulleys, so probably most gains would be from the reduction in rotational inertia, and therefore its losses in relation to changing engine speed...

but as stated before, you do get rid of almost 5kg of weight, and in my case a rather annoying squirrel sound coming from my idler pulley bearing Plus it is a full kit requiring no other parts and includes a purpose designed adjustable alternator bracket, allowing proper set up of the belt tension

Edited by pjohn151, 04 September 2009 - 07:05 AM.

[Muttley]

Liam put this on my car back in June this year, don't know about the 10-15 bhp increase but it sure does make the engine rev alot easier. Well worth the money imho. Steve

[redvts]

once the group buy is closed how do tou go about paying? ring the company direct and tell them you are on the list? just ive never done one before

Edited by redvts, 04 September 2009 - 08:44 AM.

[redvts]

whats it like to fit one of these? im assuming its a clam off job?

[starlight]

Haven't fitted mine yet, but you can access everything from the drivers side wheelarch after taking out the liner. Might need to remove the undertray, but certainly don't need to take the clam off

[redvts]

oh right not as bad as i thought then, seriously thinking about doing it

[John Boy]

Guys, couple of questions: 1. The new drive in the second photo shows several pulleys excluded from the new set up. What are these and what will drive them now. Or have I got the wrong end of the stick? 2. Will this work well with a lightened flywheel? I presume that they are both after the same goal, to speed up spin up and down. Cheers John

[starlight]

1. The new drive in the second photo shows several pulleys excluded from the new set up. What are these and what will drive them now. Or have I got the wrong end of the stick?

The other two pulleys are a belt tensioner pulley and an idler pulley. The idler pulley would be an air con unit (or power assisted steering ) pulley, which on the VX220 aren't fitted. The fitting of the kit removes the need for these (the belt tension is manually set with the alternator position in the kit) and in conjunction with the crankshaft pulley, remove just under 5kg of weight from the engine.

2. Will this work well with a lightened flywheel? I presume that they are both after the same goal, to speed up spin up and down.

Correct, the two are after the same goal of reducing rotating mass, hence its inertia, and so speeds up the engine spin up and down, so yes it would work well with a lightened flywheel

Edited by pjohn151, 05 September 2009 - 12:51 PM.

[John Boy]

1. The new drive in the second photo shows several pulleys excluded from the new set up. What are these and what will drive them now. Or have I got the wrong end of the stick?

The other two pulleys are a belt tensioner pulley and an idler pulley. The idler pulley would be an air con unit (or power assisted steering ) pulley, which on the VX220 aren't fitted. The fitting of the kit removes the need for these (the belt tension is manually set with the alternator position in the kit) and in conjunction with the crankshaft pulley, remove just under 5kg of weight from the engine.

2. Will this work well with a lightened flywheel? I presume that they are both after the same goal, to speed up spin up and down.

Correct, the two are after the same goal of reducing rotating mass, hence its inertia, and so speeds up the engine spin up and down, so yes it would work well with a lightened flywheel

Sounds good to me. Sold then:

1. pjohn151
2. Kipper
3. mac vx
4. John Boy
5.


Now just need a group buy on lightened flywheels!

[bigp2]

1. The new drive in the second photo shows several pulleys excluded from the new set up. What are these and what will drive them now. Or have I got the wrong end of the stick?

The other two pulleys are a belt tensioner pulley and an idler pulley. The idler pulley would be an air con unit (or power assisted steering ) pulley, which on the VX220 aren't fitted. The fitting of the kit removes the need for these (the belt tension is manually set with the alternator position in the kit) and in conjunction with the crankshaft pulley, remove just under 5kg of weight from the engine.

2. Will this work well with a lightened flywheel? I presume that they are both after the same goal, to speed up spin up and down.

Correct, the two are after the same goal of reducing rotating mass, hence its inertia, and so speeds up the engine spin up and down, so yes it would work well with a lightened flywheel

Sounds good to me. Sold then:

1. pjohn151
2. Kipper
3. mac vx
4. John Boy
5.


Now just need a group buy on lightened flywheels!

Any chance of getting the bracket on its own? I have a pulley and belt from another buy but could do with a bracket to make it easier to fit.

Phil

[Dynamo]

I will have one too please: 1. pjohn151 2. Kipper 3. mac vx 4. John Boy 5. Dynamo Thanks for sorting out the group buy

[starlight]

whats it like to fit one of these? im assuming its a clam off job?

OK, fitted mine this last weekend. I'll put together a set of guidelines as I have a load of pictures to go with it.

Highlights - You can fit all of this by removing only the rear r/h side wheel and archliner (I did it without taking off the undertray - but for removing the redundant idler pulley and tensioner brackets, it would be easier to get to the bolts from underneath than struggle to get your arm in through the wheel arch and around the chassis)

Issues - There are a lot of male torx headed bolts to remove. I found that an assortment of standard imperial sockets (5/16", 3/8", 7/16") fitted perfectly well without chewing up the head.

All done in less than an hour (including taking pictures).
And yes, you can tell the difference when accelerating through the gears - especially in 1st/2nd




Oh, and it got rid of my squirrel noises

Group buy discount is still available from MMG, PM me for details

[Dynamo]

whats it like to fit one of these? im assuming its a clam off job?

OK, fitted mine this last weekend. I'll put together a set of guidelines as I have a load of pictures to go with it.

Hi there pjohn151, I would like to fit this before I go off to Spa next Thursday with the Lotus on Track trip.

Would you have time to post up your fitting guide before this weekend? I'm planning to fit it this weekend, and your guide would ensure I do it properly!

Thanks

Adrian

[starlight]

As previously mentioned you will need a set of sockets that will fit the torx head bolts that are found in the engine bay. First a bit of health and safety - Working on cars is dangerous, and no liability accepted for any omissions from the following sequence - these were how I fitted the kit, and in no way form definitive instructions

Jack up rear and remove drivers side wheel


Remove the brackets from the inlet manifold to the alternator and cylinder head

[starlight]

Remove the wheelarch liner