Rotrex Supercharger

[Ant]

Well as some may know I've been working on an easy fit S/Charger option to suit the M20 and M50 engines.

Its now finished

3 specs avail, all using the same charger but the drive ratio is changed with different pulley dims.

for now we have 6.5 psi, 9 psi and 14.7 psi kits avail, the lower boost kits will bolt onto a stock late B25 with no mods to internals, however the 1 BAR kit will require the CR dropped to ensure reliability

the kits are fully R+D'd, development has been shared with another company who have years of experience with Rotrex chargers.

Unlike the Eaton blowers these are more akin to a turbo style power delivery, more up top with great midrange but no requirement for bypass valves, dump valve is of course an option

rough and ready pix to follow...








Fits both pre and postfacelift style M20 engines, anyone lucky enough to have A/C will need to sacrifice the compressor though........ you cant have it all it seems ( I tried)

Apologies for the pix quality , but you get the idea I hope.

[march109]

Ooooh I'm about to get very excited!

Do you have any numbers regarding price and power for the available option?

[oakey]

OOOOOH Have you got any power figures? or expected power figures?

[Ant]

pix added

for power, guidelines below, every lump is different so these are ballpark dependant on CR chosen etc etc etc

6.5 gives 240/240 9 should net 275/260 and the biggy is the wrong side of 300 HP ( 343 in testing on low CR with intercooler and MS setup )

its not supposed to be a sales pitch thread BTW anyone interested please drop me an Email or a call during the week.

I MAY get a few days off now this is put to bed... props to the silent partners too

[d6dph]

This looks like a very exciting step forward for E30 tuning.

Congrats on getting this rolling dude, And indeed to the silent partners.

[DRIFTBOY]

This is very interesting.

I've not had any luck finding a suitable turbocharger for my M30 and just recently been wondering about supercharging instead.

I expect they make a better noise too!

[1an]

looking good Ant,

{whispers} do you have an idea when your going to be wanting my dads car {whispers}

[Ant]

Ian, flat oot trying to make a hole dude, problem with what I do is there's always some margin for movement on the in-out dates as stuff can grind to halt waiting for a 10p part

Re the charger kits..

Prices firm TBA slightly under £3K total for the hardware inc VAT oil etc etc, , the bolts you see in the pix are not the final units that will be supplied, all will be 12.9 grade hex headed HT jobbies Edit: that is a DIY price BTW, a chip and RRFPR or similar will be needed , or MS-piggyback whatever you want.

oil reservior and lines/fitting are all included in the kits, liftetime warranty on the chargers too , bonus.

[1an]

Ian, flat oot trying to make a hole dude, problem with what I do is there's always some margin for movement on the in-out dates as stuff can grind to halt waiting for a 10p part

Re the charger kits..

Prices firm TBA slightly under £3K total for the hardware inc VAT oil etc etc, , the bolts you see in the pix are not the final units that will be supplied, all will be 12.9 grade hex headed HT jobbies

oil reservior and lines/fitting are all included in the kits, liftetime warranty on the chargers too , bonus.

no problem mate,

are these the kits that i was talking to you about when we were last down?

[prisspringle]

i'm with driftboy any m30 options??

chris

[DaveD]

a good price ..you should have had this earlier before the stock market crashed.lol

are you using the 84 or the 94 ...another supplier quotes 260bhp with the standard fitting charger and intercooler

is it going to be like that guide i got earlier in the year and have you been speaking to richard

I will have to think about it for after xmas

[march109]

agreed definatly gonna have to wait until after crimbo, but how does it compare to a turbo'd m20 Ant?

assume you have had one built up and running since you have pics and know the sort of power to expect, re drivability and cost per bhp which would you have turbo or sc?

[DaveD]

its a supercharger...no lag and power and torque from tick-over...much more driveable than a turbo

[march109]

its a supercharger...no lag and power and torque from tick-over...much more driveable than a turbo

Thats what I thought but after reading:

Unlike the Eaton blowers these are more akin to a turbo style power delivery, more up top with great midrange but no requirement for bypass valves, dump valve is of course an option

I wasn't sure so I asked? and I'm still not sure, as you've just contradicted what Ant said.

[lance1a]

hello mate, does the lower boost unit come with an intercooler as part of the package? Air-Air? Cheers. great work!

[DaveD]

its a supercharger...no lag and power and torque from tick-over...much more driveable than a turbo

Thats what I thought but after reading:

Unlike the Eaton blowers these are more akin to a turbo style power delivery, more up top with great midrange but no requirement for bypass valves, dump valve is of course an option

I wasn't sure so I asked? and I'm still not sure, as you've just contradicted what Ant said.

I quote from another revue
"Another benefit to using the ROTREX, as opposed to any displacement charger is the fact all displacement chargers produce maximum boost at about 3000 engine rpm and then tail off as you rev higher. This is a big problem when driving, as you do not want near max power at low rpm as you get tremendous traction problems, which is a particular problem if you compete in drag races and standing quarter miles, as all you do is spin the wheels and go no where. The ROTREX, being a centrifugal type charger has a nice even increase in boost pressure rising in a linear pattern, with usable extra power from 1000 engine rpm and max boost at 7000 rpm ( or at what ever you desire, depending on the engine).

The latest revision of ROTEX unit is integrated with it's own oil pump and supply as opposed to the older models which had to be connected to the engine for an oil feed. The main advantage of this is that special traction oil can be used which gives a very high standard of lubrication but does not include any friction reduction additives that are contained in modern engine oil, especially synthetic. In this configuration we are able to produce a lot more boost(up to 1.25bar), an increase of 0.4 bar more than the older units! ."

[blingsta]

Theres always been the argument of "supercharger or turbo". Ive never driven a charged motor, but under the impression and been told that its not as fun to drive as a turbo and doesnt give that boost that a turbo does? someone correct me if im wrong? Although i know the power from a charger is constant from idle as its run by the pulley where as with the turbo you have to wait for the pressure to build..

[d1mmy]

Nice one mate!


More stuff to think about!!!

[Ritchie]

I have considered a rotrex for my M30 although tbh i havent looked that far into it. An old workmate of mine supercharged his Golf VR6 and it sounded fantastic! Very mad-max-esque.

[Gunni]

So are you not using anything to relieve pressure?
So it´s ratio then must be linear in power delivery?

My friend with 2 rotrax centrifugals on S62 is using bleed valves so that boost pressure is gotten earlier and then bleed off to maintain the desired max boost pressure until rpm, same as a wastegate basically.

[ste]

Well as some may know I've been working on an easy fit S/Charger option to suit the M20 and M50 engines.

And M52 I'm guessing?

Seriously interested in more details Ant, will give you a bell dude.

[buster]

so whens the s50 version coming out ?

[Ant]

Hadn't factored it TBH Andy, ASA,ESS and CA all do a kit already for these.

Want me to look into it dude ?

[agreen]

ant you have a pm

[buster]

Hadn't factored it TBH Andy, ASA,ESS and CA all do a kit already for these.

Want me to look into it dude ?

yes please.

[ian332isport]

Hadn't factored it TBH Andy, ASA,ESS and CA all do a kit already for these.

Want me to look into it dude ?

yes please.

I reckon it would fit nicely where the air pump would normally be

[old_skool]

Hadn't factored it TBH Andy, ASA,ESS and CA all do a kit already for these.

Want me to look into it dude ?

yes please.

I reckon it would fit nicely where the air pump would normally be

[Jhonno]

interesting..

[hoshy]

very sweet. after reading the corky bell book I'm starting to wonder if centrifugal is the way to go rather than the eaton. hmm.

Ant, these look awesome.

[daimlerman]

Is this a kit of bits to DIY? Or is the price mentioned include fitting ECU mods etc? Would it destroy my 2.7?

[Onz]

hmmm, what about Eaton? I thought Eaton chargers were the best type of charger units.

[appletree]

Eatons arn't realy the best infact there probly the worst for efficency but it depends on the power dlivery you want.

If you want a boost in low down torque and a smooth power then the "twin screw" type blower would be better as it is much more efficent than a eaton (roots) type blower but then is also alot more expensive due to the machining process, thats why so many manufactures use the eaton unit as there cheeper and theres been more development done with them.

The centrifugal type blower seams to behave more like a turbo as in you get more boost mid range and up top although theres no lag theres still a eliement of "slipage" as its not a positive displacement charger untill the charger comes to the sweet spot and it all comes together.

I did look in to the centrifugal type blower when i did mine but due to the cost of the units i couldnt realy afford to just "suck it and see" where as a £200 eaton unit could always be sold on easly, nice to see Ant tuck the plunge and came back with some good results!

I would love to build a low comp IS lump and use a rotex on that

[Onz]

nice comments mate, i wasnt sure about the different types of blower before. I am familiar with the G60 blowers from Vw and the Eatons. What type is the G60 just oout of interest? And do you know which type they used on aeroplane engines. I read a really interesting article about the lancia supercharged and turbo charged engine recently. I think they used a centrifugal blower on that but i am not sure.

[buster]

Hadn't factored it TBH Andy, ASA,ESS and CA all do a kit already for these.

Want me to look into it dude ?

yes please.

I reckon it would fit nicely where the air pump would normally be

good idea
Isnt the A/C pump in the same place also ?

[orr]

s50 for me to please