40 replies to this topic

[Jonny2spud]

Has anyone used a rotrex supercharger on a z22se? They seem to have a great reputation but I can't seem to see much in conjunction with a vx220 na. As always, your help is very much appreciated.

[Bargi]

I think Dutch Peter who writes the ODBTuner software upgrade for NA ECUs may run one. I'm sure our Euro Oracle that is Smiley will confirm

[smiley]

Yes, peter runs one. (a C30 i think)

He did 317 horsies on the last dyno day (which is not enough; he wants more)

 

 

You put it where airco pump goes on a Z22se: 

 

After putting his dyno sheet against a harrop that did 316 horsies that day, it was interesting to see that the torque curve started slightly later, but looked quite similar in growth. (i did not expect that) 

 

Air is pushed into the oem manifold. (This is Peters car, where a 2.4 inlet is used)

 

 

If you keep the system small, you can even put the little cooler in the right ear, so no front clam off job. 

Edited by smiley, 20 December 2013 - 08:38 PM.

[jonnyboy]

Interesting!

[Sticky]

Rotrex into iTBs ftw

[Jonny2spud]

Thank you for the information!!! This is a really interesting development!! This really is a great forum with so much information made available so quickly! If anyone else has explored this option I would love to know your comments. Thanks

[techieboy]

There's an Italian Speedster that did it a few years ago too, details are on the site somewhere.

 

You need to decide what characteristics you want though. Roots/positive displacement supercharges (like the off the shelf GM solution) delivers in a totally different way to a centrifugal charge like the Rotrex and you need to be more sure of what you want to achieve in order to spec the size of it and where it delivers in the first place.

[Ponk]

Not quite what you're looking for but i ran a c30-94 on a Peugeot 106 Rallye for a couple of years. It was a fantastic unit which gave a very revvy feel (think VTEC) as peak power was high up the rev range. Made 210 bhp and 185 ft lb from a 1.6 engine (125 bhp standard). Have a word with TTS performance for all things Rotrex.

[Firthy]

That looks such an OEM conversion.... Existing air box, manifold (no need to change alternator), no faffing with relocating the ecu, no worries with the fuel lines or belt slipping hugely either I wouldn't of thought... Did Peter make his own rotrex bracket? Where's the catch... Any more info?

[Bargi]

There really isn't much to the conventional SC Stg 2 conversion. As for fuel lines, there's been plenty of SCs with the occasional belt shredding and no fuel lines ripping apart. In fact I believe turdos have more of a problem with fuel lines going by what I've seen from Wolfie

[smiley]

Did Peter make his own rotrex bracket? Where's the catch... Any more info?

 

Peter indeed made (or has let made) his mounitng bracket.

There is no catch. Rotrex is popular on lotus conversions.

Because of cheap availability of the M62 system, it's not really done much on ours for some reason.

 

If courtenay would add it to the shop, incl a premade bracket, it would probably be interesting for the harrop club, as you can chase the same numbers with one of these. 

 

The most difficult part is to get a clear grip on the feeling of power delivery of centrifugal versus roots like techie said.

All i know is that similar peak power delivery dyno sheets put over each other looked scarely similar.

Only difference i could see was the rotrex starting to climb about 500 rpm later then the harrop.

This summer i'll try to pinch a ride in Peter's car. Maybe that will give me a better feeling on the difference then those dyno sheets.

 

Edited by smiley, 21 December 2013 - 08:25 AM.

[Firthy]

Thanks guys..... As you say Smiley I'm sure if there was a pre made bracket this would be more popular... Completely agree that there isn't much to a stage 1 or 2 either... TBH I am only interested in a small power hike equivalent to a stage 1 or slightly more and would want a very neat no hassle conversion. My car is tracked more and more now so I like the idea of less heat and less noise.... Am I right in saying this could potentially be a better at managing heat ( in take temps) and noise on track? There is no way I would do an sc without obd due to the reasons around having to block of the air whole and not let the bottom end breath..... I have seen to many failures.... so I would want OBD anyway.... Are there any others than Peters running reliably in this state of tune?

Edited by Firthy, 21 December 2013 - 09:58 AM.

[PaulCP]

There's an Italian Speedster that did it a few years ago too, details are on the site somewhere.  .

Should find it if you search for posts by "Ricky" back in 2004/5

[techieboy]

Ah Ricky had one as well? I was thinking of someone a little more recently; maybe it was Ricky's old car in somebody elses hands.

 

I enquired (as did MandarinVX) about getting one a few years ago but the costs got absolutely stupid in comparison to the GM M62 conversion as TTS wanted to do most of the conversion before they'd actually sell a kit or even a plain charger (custom mounting bracket, custom pulleys, custom pipework etc). It all got a bit too complicated when you had to start cramming in the fussy external oil system and they still reckoned an intercooler or chargecooler was needed (which I think Bemani or Komo-Tec or whoever did the Elise/Exige Rotrex conversions also fitted). That and at the time, the need for an aftermarket ECU put me off it. On the bright side, it would have worked perfectly with the cast Saab B207 turbo inlet manifold (surprised Peter has stuck with a plastic manifold ).

 

If spec'd right, it's a good choice, especially on a track car and a much better choice than an overdriven M62 or Harrop. The temptation is to probably get too big a charger and leaving yourself with a bit of blackhole in the torque delivery until it spins up to a fast enough speed (that was my impression of driving a rotrex equipped S2000). Decide in advance where your redline is going to be and size the charger to deliver it's max power just before that and it's probably spot on and don't get get swayed by the "it can give you 500bhp" at 100,000rpm kind of specs. It definitely makes a lot of sense on an S2000 with a 9k red line, especially given the facts it got less torque than an NA VX but I do like the delivery of the M62 on a car that's used on the road as much as on the track, makes for a much better drive.

 

ETA: If the above pic is all Peter is running on his car, I can see why he wants to get water/meth injection support into the standard ECU.

 

[smiley]

Am I right in saying this could potentially be a better at managing heat ( in take temps) and noise on track?

 

No, peter is facing the same issues as the rest of the trackers, and had added water injection to his system for that.

For noise he just avoids the tracks with low tollerance. (as i will also be doing as from now) 

[Firthy]

Thanks Techie very interesting.... Yes I would only be looking for an extra 70 - 80 bhp I wouldn't be chasing huge numbers... So if I could just run the oil cooler in the ear without the charge cooler that would be ideal..... I'm guessing the main issues are: - The bracket - What size for optimum torque and an extra 70 bhp Plus I wouldn't have a clue where to start

[smiley]

 

ETA: If the above pic is all Peter is running on his car, I can see why he wants to get water/meth injection support into the standard ECU.

 

I'm not 100% sure of the current setup, as that pic was taken a few years ago.

Back then he did not have the front mounted pro alloy cooler. Not sure if it's in now.

 

When running 260isch horsies he had a restricter in the air supply, as the C30 was to effective. 

Once enforced he removed it, resulting in the 317 result.

I think he's going for a bigger rotrex this winter.

 

Unfortunately Peter does not post on his setup in the dutch forum, so info is limited. 

 

[Firthy]

Hahaha oh fair enough... No quieter and still heat issues then = not worth the hassle

[techieboy]

From memory, Rotrex used to do a "sizing" type calculator on their website that would give you an idea of the best match supercharger to match your engine, which direction the pulley runs at and what sort of boost you wanted and whereabouts. They'd then make a suitable pulley (their's are 8-rib as standard which obviously wont work on our cars) to scale it right. Just had a cursory look on their website and there's nothing obvious.

 

The pain in the arse thing from a making it all fit point of view was that all of the external oil system had to be mounted lower than the charger itself as it's effectively dry sumped, which is a potential headache when the charger is mounted as low as that on our engines. Would be good to see what Peter did on that front.

[FLD]

The rotrex external oil system is essential for proper operation.  They use a planetary gear system that needs a very specific viscosity hence the special oil system.  This allows them to spin the compressor faster making the unit smaller.  You could go for a vortech which can run from the engine oil circuit (like a turbo) but it is a larger unit.  The are a great unit, far more efficient than a roots blower but do lack the balls low down.  Strapped one to an RV8 once.  That was good.