2006 Rotrex SC 95% complete Dyno attached

[cpeteod]

First I want to thank Dustin for all the hard work he put into this project. Many long nights over the winter in my garage. Second Rob from No Limit Motor Sport Import Performance Parts. He is the owner and has given me some great help. Also taught me a thing or two about tuning. Great guy to bring your car to if you need anything. Ok for the fun stuff.

Project 2006 Lotus Elise Rotrex SC
SC unit - Rotrex C30-94 unit
Fuel Injectors - Blitz 660cc
Cooler type- Air to water intercooler
Pulley size- 100mm
PSI produced- approx 9 max
Fuel Pump- Walbro 255
HP Total - 281.6 (all numbers to the wheel)
Torque - 186 (all numbers to the wheel)
Clutch - Stock (sliping a little but have a new AEM ready for winter install)
Fuel Injection Control - AEM FIC/6
Gain - 106hp and 60 ft-lbs

[Demonized]

Interesting, but evidently the same result as a turbo a weee bit too big for the application.

Edit; did you guys try playing with the cam switch?

I recall seeing Dyno results of a turbo'd Elise that showed similarly odd powerband, messing with the cam switchover point and creating a smooth line, as opposed to the ~100hp jump from 6500 to 8000.

[ggelise]

Congratulations Chris! The instillation looks top shelf. How does she drive? That is a great number and only 60% of what the blower can pump! Great choice man. I am biased but think that this blower/charge cooler combo is the absolute best solution.

[kmt63]

i was wondering if the rotrex would work on the 2zz.well here is the proof.how does this compare cost wise to the other superchargers?

[Darth G-F]

Can someone please pass up the crack pipe?

That car barely makes any more power than stock up to 7000rpm, then BOOM you get hit by 100hp in a matter of 1000rpm just to hit on the rev limiter.

It must feel good to be hit by 100hp so quickly. But this is not an efficient set up imho.

[Ryephile]

Looking at the dyno curve means this setup would be great for dragstrip or perhaps roadcourse with a close-ratio 'box, but around town it'd feel pretty much like....


nothing...nothing...nothing.......nothing......... ...FFFAAAAAASSSSTTTT!!!



Congratulations on the buildup, it looks top shelf indeed. Rotrex aren't inefficient, however since they're drive RPM dependent they are inherently high-strung at the expense of low-end torque. This is why Rotrex are typically used on big 'merican V8's that have plenty of low-end grunt by themselves. Thanks for giving some decent data, along with a proper before and after dyno!

[cpeteod]

Getting the cam to switch over at 4500 is the key and I have to figure out how i can get this done. I may have to beg Charlie . As far as cost. Just decided to tinker with this project. I am sure Rob can reproduce this with a little help. Doing the install myself i would say i stayed under my 5k budget.

[cpeteod]

Originally Posted by ggelise

Congratulations Chris! The instillation looks top shelf. How does she drive? That is a great number and only 60% of what the blower can pump! Great choice man. I am biased but think that this blower/charge cooler combo is the absolute best solution.

Thanks for the kind words, and for the people with all the negative stuff to say, feel free its your opinion. What I did wasn't to have a better kit because I must say Charlie's solution and BWR are both great, I just wanted to have fun. Having fun I did.

[Tang0_au]

hmm, thats a REALLY strange power curve ...

i have a rotrex on my 1zz-fe (running 8psi) powered elise and its a very linear power curve ... none of this big lag, then booooooooost ... i think you have some more work to do on the dyno ? check out the 2zz rotrex MR2-spyders on Spyderchat.com: The Online Community for Toyota MR2 Spyder Enthusiasts!


did all the work myself and had to figure out a huge amount of stuff as people seem relucatant to do it on the lotus - dont know why as its been done a LOT on mr2-spyders ... looks like the general design we come up with is pretty much the sam tho, good to know i'm running a full standalone ecu as well ...

great work tho, must be a hoot to drive !

[Monsi]

wtf? is that a centrifugal blower?

[Ryephile]

^^ Yes, Rotrex are centrifugal superchargers, hence the ramp in torque gain. They do not have lag like a turbo, since they're always spinning in proportion to engine RPM. They inherently need lots of engine RPM [or a massive overdrive] to provide enough Rotrex shaft RPM to get onto the compressor map islands with enough efficiency to be effective. I don't see anything unusual with the dyno plot other than it would probably benefit from a lower cam-switchover.

Again, congrats on the build-up!

[cpeteod]

Originally Posted by Tang0_au

hmm, thats a REALLY strange power curve ...

i have a rotrex on my 1zz-fe (running 8psi) powered elise and its a very linear power curve ... none of this big lag, then booooooooost ... i think you have some more work to do on the dyno ? check out the 2zz rotrex MR2-spyders on Spyderchat.com: The Online Community for Toyota MR2 Spyder Enthusiasts!


did all the work myself and had to figure out a huge amount of stuff as people seem relucatant to do it on the lotus - dont know why as its been done a LOT on mr2-spyders ... looks like the general design we come up with is pretty much the sam tho, good to know i'm running a full standalone ecu as well ...

great work tho, must be a hoot to drive !

Very fun to drive, just always keep the RPM range up. And I did use many things I found on the web to help with this considering it has been done before on 1zz and 2zz motors many times. Plumbing and the bracket aren't the same even though i started with the bracket design off a Celica GTS but that had to be modified.

[Demonized]

Originally Posted by Ryephile

I don't see anything unusual with the dyno plot

[LordZ]

Congratulations on getting it all together. I'm REALLY glad I went with my VF now though after seeing that dyno chart.

While it might be a blast for you on the street, that would suck at the track for me. Way too much lag on that powerband.

But I bet it is a blast on a nice straight road.

[ggelise]

Can someone please pass up the crack pipe?

That car barely makes any more power than stock up to 7000rpm, then BOOM you get hit by 100hp in a matter of 1000rpm just to hit on the rev limiter.

It must feel good to be hit by 100hp so quickly. But this is not an efficient set up imho.
__________________

Well proven technology- it is just a tuning issue. The crack pipe users will slow way down so you can get a whiff as you are getting passed .

[kmt63]

i looked at one of the links above from the spyder site.that guy had a nice torque curve.he was using hydra for the ecu.

[Ryephile]

Originally Posted by Demonized

Easy there killer. What I meant was I don't see anything seriously wrong with the curve. I'm not saying it's a torque curve ideal for auto-cross, drag racing a ZR1, or is flawlessly tuned, but then again the OP hasn't posted enough datalogging for us to give any sort of useful response or advice. Like we both said in earlier posts, a lower cam switchover RPM would probably significantly help make the engine less 2-mode and more progressive.

Cheers,
Ryan

[Darth G-F]

Originally Posted by ggelise

Well proven technology- it is just a tuning issue. The crack pipe users will slow way down so you can get a whiff as you are getting passed .

No need to slow down, just stay below 7000 or and you will never know which way the litle Katana went. And if I were to add the VF2, you would never know there was VF car in the area...

Rotrex is proven technology for big block, low torque cars that run out of puff at higher rpm.

I just think this is not the right tool for the job. I don't question the op work at all. Just that the SC choice doesn't look like something I'd want.

Same thing happened on the Miata forums a few years back when a company put up a centrifugal SC kit. All the disadvantages of both the turbo and SC. With no advantages of either...

[dustylax]

Rob said there was a issue with a wire not being right, glad you got it sorted out and now the tune went well Chris. It made just what we expected which is always nice, the only thing im not exactly happy about is the torque of course but i guess its sorta good, it will save you some tires haha. I am expecting higher numbers both HP and TQ once you get that ACT clutch in there.

[xtn]

Similarly to a turbo installation... If that unit is only rolling at 60% capacity near the engine's redline and the boost isn't hitting until late... couldn't you select the next lower sized unit to bring the power band down a bit?

xtn