Cosworth Supercharger Owners Thread

[Matt@Cosworth]

Originally Posted by DavieOxide

Hi folks,

I'm new to this forum but have had been reading through through this thread with great interest. Lots of really good information on here!

I have been running the cosworth SC for about 9 months now and have put about 16k miles on her . Beginning to get itchy fingers again so i have just ordered forged internals and a bunch of other good stuff.

I am going to make up a set of pulleys to speed up the SC. Does anyone have any thoughts/comments on running a secondary set of pulleys in front of the crank pulley? It would save changing all the stock pulleys and you could run a really neat short belt. As far as I can see the only thing in the way is the inlet pipe and I would think this could be re routed. I'd really appreciate some ideas on this.


Cheers in advance.

if you're going SD ( speed density) then yes you can modify the inlet pipe to not include the stock airbox and MAF meter , if you need some support to achieve this then I'd be happy to help where I can
the minimum radius you can run is 25mm on a PK tooth belt so bear that in mind when designing your nose pulley and you'll need to run about a 3:1 ratio to get the boost into the sweet spot for the unit, so as the crank pulley is 137mm diameter ( I think from memory) then you will need to make the crank pulley bigger and possibly require 8 ribs not 6 to account for the extra power to drive it.
however one issue with extending the length of the pulley so its no longer overhung means that you will be canterlevering the bearings in the nose casting
now they will cope with a certain level of load but the overhang needs to be kept to a minimum and some kind of tensioner will be required as you need to try and achieve a minimum of 180 to 200 degrees of belt wrap on the charger pulley

[weederr33]

Originally Posted by DavieOxide

Hi folks,

I'm new to this forum but have had been reading through through this thread with great interest. Lots of really good information on here!

I have been running the cosworth SC for about 9 months now and have put about 16k miles on her . Beginning to get itchy fingers again so i have just ordered forged internals and a bunch of other good stuff.

I am going to make up a set of pulleys to speed up the SC. Does anyone have any thoughts/comments on running a secondary set of pulleys in front of the crank pulley? It would save changing all the stock pulleys and you could run a really neat short belt. As far as I can see the only thing in the way is the inlet pipe and I would think this could be re routed. I'd really appreciate some ideas on this.

Cheers in advance.

If you end up doing this, you should make a build thread on here so we can see what all you've put into the engine/ transmission. I'd love to know the whole set up. What internals did you go with?

[DavieOxide]

Originally Posted by Matt@Cosworth

if you're going SD ( speed density) then yes you can modify the inlet pipe to not include the stock airbox and MAF meter , if you need some support to achieve this then I'd be happy to help where I can
the minimum radius you can run is 25mm on a PK tooth belt so bear that in mind when designing your nose pulley and you'll need to run about a 3:1 ratio to get the boost into the sweet spot for the unit, so as the crank pulley is 137mm diameter ( I think from memory) then you will need to make the crank pulley bigger and possibly require 8 ribs not 6 to account for the extra power to drive it.
however one issue with extending the length of the pulley so its no longer overhung means that you will be canterlevering the bearings in the nose casting
now they will cope with a certain level of load but the overhang needs to be kept to a minimum and some kind of tensioner will be required as you need to try and achieve a minimum of 180 to 200 degrees of belt wrap on the charger pulley

So are you suggesting that I remove the MAF sensor altogether and just use the MAP sensor in the inlet manifold? I was just going to be route the pipework but if you think this is feasible then perhaps it would be a better option. Thanks for offering to help.

I will look at fabricating a tensioner bracket to get the correct pulley wrap. How close are the bearings on the SC? I could always make up a front bearing bracket to take the load but then perhaps just changing the full pulley set would be easier after all...

[Norville Rogers]

So what is everyone's stocktake view on the Cosworth? In the market and in the UK but not overly impressed after reading this thread

[ajc209]

Originally Posted by Norville Rogers

So what is everyone's stocktake view on the Cosworth? In the market and in the UK but not overly impressed after reading this thread

What is it you're not impressed with?

[weederr33]

Originally Posted by Norville Rogers

So what is everyone's stocktake view on the Cosworth? In the market and in the UK but not overly impressed after reading this thread

I think it's a great overall package. For some the price is a bit steep, but with all of the R&D involved, it's warranted. Plus I like the looks of a positive displacement supercharger vs a centrifugal.

What exactly are you looking for, and what does not impress you about the kit vs the others?

[Matt@Cosworth]

Originally Posted by DavieOxide

So are you suggesting that I remove the MAF sensor altogether and just use the MAP sensor in the inlet manifold? I was just going to be route the pipework but if you think this is feasible then perhaps it would be a better option. Thanks for offering to help.

I will look at fabricating a tensioner bracket to get the correct pulley wrap. How close are the bearings on the SC? I could always make up a front bearing bracket to take the load but then perhaps just changing the full pulley set would be easier after all...

there's a double row bearing in the nose just behind the pulley flange
so the standard pulley is overhung to put load in the middle of this race
if you start overhanging the front of the existing pulley you'll cantilever on this bearing so a 2nd support would be wise. Perhaps incorporate it into your new tensioner bracket ?

the reason I say to consider SD from the beginning is the Standard MAF installation starts to clip ( reach maximum voltage) at about 300Bhp
and running a Bar of boost means you'll max it out early on unless you remount it in a larger tube

[weederr33]

Originally Posted by Matt@Cosworth

there's a double row bearing in the nose just behind the pulley flange
so the standard pulley is overhung to put load in the middle of this race
if you start overhanging the front of the existing pulley you'll cantilever on this bearing so a 2nd support would be wise. Perhaps incorporate it into your new tensioner bracket ?

the reason I say to consider SD from the beginning is the Standard MAF installation starts to clip ( reach maximum voltage) at about 300Bhp
and running a Bar of boost means you'll max it out early on unless you remount it in a larger tube

Speaking of pulleys. Have you guys done any testing on the 10% smaller pulley and or received any more quotes on cost?

[Matt@Cosworth]

I'll chase it up

[ajc209]

Originally Posted by weederr33

Speaking of pulleys. Have you guys done any testing on the 10% smaller pulley and or received any more quotes on cost?

I think he's had it on the dev car for a while amd its been working fine but they dont intend to validate it by doing all the endurance testing they did for the stage 2 package.

If I recall something alone the lines of "all warrenty or implied warranty would be out the window if it puts a leg out of bed"

So its very much a, you can fit this but you are on your own. Which is the bit that put me off personally.

[DavieOxide]

Originally Posted by weederr33

If you end up doing this, you should make a build thread on here so we can see what all you've put into the engine/ transmission. I'd love to know the whole set up. What internals did you go with?

Yeah, I will try and write something up. I'm usually rubbish at keeping forums up to date lol.

Got Carrillo 10:1 pistons and forged rods on the way. Kelford uprated valve springs, ARP stud kit, cosworth head gaskets also in the pipeline.

Gonna take a few months until it's all done...

[weederr33]

Originally Posted by ajc209

I think he's had it on the dev car for a while amd its been working fine but they dont intend to validate it by doing all the endurance testing they did for the stage 2 package.

If I recall something alone the lines of "all warrenty or implied warranty would be out the window if it puts a leg out of bed"

So its very much a, you can fit this but you are on your own. Which is the bit that put me off personally.

Yeah, I can see where you're coming from. In terms of warranty, we're talking the supercharger, correct? If so, how long is the warranty?

[Akrelease2.0]

Does Cosworth have any plans on making a CARB compliant tune? I am also curious on the expected release date of the third stage.

[weederr33]

Originally Posted by Akrelease2.0

Does Cosworth have any plans on making a CARB compliant tune? I am also curious on the expected release date of the third stage.

Although there isn't an actual "carb" tune, there is the Stage 2.1 tune (supercharger plus catback) and that is essentially a carb set up without the fancy sticker. But... is Alaska a carb state?

As for the Stage 3... yeah....... BUT you'll be happy with just the supercharger and full exhaust set up.