[ChopTop]

So i just noticed DDM signature:

2.4L - Stage 3 Supercharged - 305whp - 93 octane
2.4L - Rotrex Supercharged - 340whp - 93 octane
2.4L - Custom Turbo - 304whp - 93 octane
2.0L - 2871 Hybrid turbo - 371whp - 93 octane

And I was surprised to see the WHP differences between the Rotrex SC and the Stage 3 MP62. Is there a simple answer for the 35whp difference?

Due to the price differences and complexity involved, I keep waffling between supercharging and a V8.

 

[DaveOC]

So i just noticed DDM signature:

2.4L - Stage 3 Supercharged - 305whp - 93 octane
2.4L - Rotrex Supercharged - 340whp - 93 octane
2.4L - Custom Turbo - 304whp - 93 octane
2.0L - 2871 Hybrid turbo - 371whp - 93 octane

And I was surprised to see the WHP differences between the Rotrex SC and the Stage 3 MP62. Is there a simple answer for the 35whp difference?

Due to the price differences and complexity involved, I keep waffling between supercharging and a V8.

I've seen one of Dave's installations of the Rotrex and it is very clean. One of the guys from Texas had it at our Dells meet this past September. It was a very nice install and was very typical of DDM's quality installations.

For some pictures of the Rotrex, and a timeline for availability: http://www.solsticeforum.com/forum/f101/stage-1-super-charger-121378/

:dthumbs:

.

 

[[email protected]]

So i just noticed DDM signature:

2.4L - Stage 3 Supercharged - 305whp - 93 octane
2.4L - Rotrex Supercharged - 340whp - 93 octane
2.4L - Custom Turbo - 304whp - 93 octane
2.0L - 2871 Hybrid turbo - 371whp - 93 octane

And I was surprised to see the WHP differences between the Rotrex SC and the Stage 3 MP62. Is there a simple answer for the 35whp difference?

Due to the price differences and complexity involved, I keep waffling between supercharging and a V8.

The biggest difference is the power delivery of the different superchargers. The Rotrex is a centrifugal supercharger, which means it builds boost with RPM and peak power comes closer to redline. The MP62 based superchargers basically hit peak boost as soon as you open the throttle at any RPM and maintain that boost throughout the rev range. That makes it sound like the MP62 superchargers are going to be better all of the time, however that is not the case. The Rotrex units make more power than the MP62 at the same pressure and there are different versions available that can make lots of power with the same brackets and charge tubes.

All of that being said, from our experience, this is how you make the choice -

Automatic or manual car and you like to rev the engine to 7000RPM all the time = Rotrex
Manual car and like that strong bottom end and mid range = MP62 kit

I really like the Rotrex since it is a high ROM screamer and is also silky smooth, but then I am used to revving the engine out to redline all the time coming from the small displacement 4 cylinders in the Miata.

I am actually finishing up another install right now that is our install for the instructions, I can post some more pics up when I am done also. The MP62 new prototype outlet manifold should be here in a couple weeks and if that validates out well then we will start back with the MP62 kits also.

Hope that helps and doesn't just make it more confusing
Dave

 

[ChopTop]

Thanks Dave, I appreciate the explanation. I don't like the idea of running my car to redline so it looks like the MP62 would fit my driving style better. But if I win the lottery it's a LS7 for me.

 

[[email protected]]

Finished up the final version of the Rotrex install, more info in the coming days.

There will be 2 different versions of the Rotrex kit. The base version which is pictured below is for those that want a really stock OEM feel and sound from the car. It is designed to work with the stock exhaust manifold, stock catalytic converter and stock cat back exhaust. So it is hard to tell that anything has been done to the car from outside without opening up the hood. On automatic cars we typically would see around 240hp at the wheels with an exhaust and high flow catalytic converter or about 100hp gain at the wheels with the usual Stage 2 supercharger we sold, with the Rotrex we are seeing around 250hp with everything else being completely stock. With changing out the exhaust, catalytic converter and manifold you can gain an extra 10hp at the wheels also, so it makes more power than the usual Stage 2 supercharger.

We will also have the option for the larger Rotrex that looks basically the same but moves more air, that one does require long tube headers and full exhaust and we have made as much as 340hp at the wheels on a manual car with those mods. Although we will probably set it up for around 300-310hp at the wheels, which is more than the usual Stage 3 that we offer.

Once again the power comes on differently between the 2 superchargers, they are both a lot of fun though, enjoy the pics!

More information on the Rotrex before the official announcement - http://www.ddmworks.com/Rotrex-Supercharger-Kit-for-the-24L-SolsticeSky-by-DDMWorks_p_656.html

 

[RedOne07]

So i just noticed DDM signature:

2.4L - Stage 3 Supercharged - 305whp - 93 octane
2.4L - Rotrex Supercharged - 340whp - 93 octane
2.4L - Custom Turbo - 304whp - 93 octane
2.0L - 2871 Hybrid turbo - 371whp - 93 octane

The equivalent of US Regular costs 6.7 US$ a gallon over here, and the equivalent of US Premium 7.05 US$ a gallon. So I was wondering, is there a SC or Turbo option that is happy with regular gas ?

Also wondering what above DDM upgrades will do to the MPG ?

 

[JohnWR]

The equivalent of US Regular costs 6.7 US$ a gallon over here, and the equivalent of US Premium 7.05 US$ a gallon. So I was wondering, is there a SC or Turbo option that is happy with regular gas ?

Also wondering what above DDM upgrades will do to the MPG ?

With that small of a price penaltly for premium I don't think I would worry about it. If my math is correct you are paying $0.35 more per gallon for premium. Most of the stations in this area are charging $0.75 more per gallon for premium. Granted, you are paying a lot more to start with, but a 5% increase is rather more palatable than a 35% increase.

And either increase is just part of the cost of more power from a small engine.

 

[RedOne07]

Thanks John. I don't worry about it, but would be stupid not to look into it

 

[[email protected]]

The equivalent of US Regular costs 6.7 US$ a gallon over here, and the equivalent of US Premium 7.05 US$ a gallon. So I was wondering, is there a SC or Turbo option that is happy with regular gas ?

Also wondering what above DDM upgrades will do to the MPG ?

There is not going to be much you are going to be able to do with the stock 10.4:1 and much boost on 87 octane. If you are going to be running any boost pressures more than just a couple psi you will need to be running atleast 91 octane.

Hope that helps,
Dave

 

[RedOne07]

All of that being said, from our experience, this is how you make the choice -

Automatic or manual car and you like to rev the engine to 7000RPM all the time = Rotrex
Manual car and like that strong bottom end and mid range = MP62 kit

So there is no choice for an automatic ?

I have a automatic and am looking for more oompf bottom and mid range.

 

[[email protected]]

So there is no choice for an automatic ?

I have a automatic and am looking for more oompf bottom and mid range.

Actually, with the automatic you can use any of the supercharger kits and most of the turbo kits out there without any issues. The PD kit is probably what you are looking for and will add the most low and mid range power. Our new castings are shipping to us next week for that kit and we expect them here after we get back from NASSM for testing.

Let me know if there is anything else I can answer or help you with,
Dave

 

[ChopTop]

Dave, how do/did you determine that the internals of the 2.4 (177HP/166TQ) can handle an additional 100HP+?

 

[RedOne07]

Thanks Dave.

With PD Kit you refer to Positive Displacement Kit , the MP62 Kit, correct ?

Can't wait till those new MP62 kits are available and field tested. I am very reluctant to take this big (for me) step. So I will first go for the Stage-1.

Are the Installation Instructions already available , or is there perhaps an estimate how many hours it will take to do the install ? I want to use that information so the Chief Mechanic of the shop can guesstimate the total cost.

 

[nighttripper]

Anything on the new castings?

 

[ChopTop]

Anything on the new castings?

See DDM post #8 for MP62 status: http://www.solsticeforum.com/forum/f11/supercharger-waiting-list-131281/#post1868362 But the gist of the post is that DDM isn't going to comment on the availability MP62 until it's ready for sale.

FWIW, you'd probably get the most current information by calling DDM and talking to Dave or Ivy.