Optimax High Performance Modifications

[t_nipper_74]

I am a new Optimax owner and am already curious to what high performance modifications are available to these motors... I am aware of the Simon Lightened Flywheel and am looking at doing this as my first mod. Has anyone had any experience with this product? What other options are available for these DI motors that are reasonably priced? I know Simon can build a 335HP motor, but I'm not looking for that much power, nor do I have that kind of budget.

I am looking more toward lightened flywheel, computer mods, and so on... I haven't herd anything about exhaust tuner mods on these motors though??? What are the more budget oriented options available for these motors and what kind of performance gains are seen? Also, I believe the rev limiter is set at 5750 on my motor... This seems kind of low to me. Can this be raised safely to yield more performance? If so, how many RPM's and what kind of gains?

If many of these mods are available for the XS and Pro XS 3l motors as well, maybe a similar modification thread could become a sticky??? I think it would be very useful to many who would be open to budget minded modifications. Plus, I believe Simon is a sponsor. Thanks for the replies


Modified by t_nipper_74 at 11:29 PM 6/9/2009

[EuropeanAM]

Have you spoken with Eric yet about your concerns?

He has some information on his website at: http://www.simonmotorsports.com

And yes, Eric is indeed a BBC Sponsor.

The flywheel and rev limiter "mods" are just that- they are a "modification of the product". I have not seen any evidence that these tamper with the "emissions footprint" of the engine- and I commend Eric highly for that

As for the tuner mod (as I recall, the tuner itself is not Eric's)- that's a little different. It does change the airflow characteristics of the engine slightly- and I've not yet seen enough data to make any judgement call, other than on a very limited number of engines. Perhaps some others who have tried it would like to chime in with their experience.

[Todd D]

Here is a link to the Hydro Tech tuner.

http://www.bbcboards.net...97386

[Bass Commander]

Eric Simon performed the flywheel mod and reflashed my ECU on my 250XS...runs like a top...a 92+ mph top that is

[t_nipper_74]

What about a set of reeds? I know they are a good way to squeeze out some power from motorcycles, lol which are a little more familiar to me. Does anyone make a set of performance reeds for these motors?

Also, what about the poppet diverter? What exactly is it, and is it worth the gains for the money? I see it on the Hydromotive website, and there was a pic of one with the exhaust tuner on an earlier thread when the tuner was just coming out.

Right now I am looking at the Simon Lightened Flywheel & ECU reflash and the Hydromotive Exhaust Tuner. I would think this combo would put a 225 up close to a 250 in performance...

[esdbass]

I think you should go to Hydro Tec's website and see what they did to a stock 250 XS, while this isn't your motor I think a combined upgrade from Eric and Wayne Worthy at Hydro Tec is the top of the food chain for your type of motor

[t_nipper_74]

I have checked out their site, and plan on doing a combination of what they both have to offer. Is Direct Injection the reason that you never hear of any head milling or modifications for increased compression and horsepower? I know that on most of the EFI motors that is the best bang for the buck, and the only thing I can figure out is that head modding is not an option of the Opti/XS motors...

[EuropeanAM]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by t_nipper_74 &raquo;</TD></TR><TR><TD CLASS="quote">I have checked out their site, and plan on doing a combination of what they both have to offer. Is Direct Injection the reason that you never hear of any head milling or modifications for increased compression and horsepower? I know that on most of the EFI motors that is the best bang for the buck, and the only thing I can figure out is that head modding is not an option of the Opti/XS motors...</TD></TR></TABLE>

You're correct in your assumption. These engines (like the EFI's) work on a "speed-density" theory of injection. For any specific set of parameters (barometric pressure, engine temp, throttle position and RPM) there is a fixed table that supplies a fixed volume of fuel. Alterations to the airflow characteristics result in lean conditions (and quite easily, I might add).

The EFI's, on the other hand, were a little more forgiving, since they ran "fat and rich" most of the time anyway.

In addition, if you "could" safely modify to the fuel curve, you would still have to overcome the hurdle of "o-ringed heads", and would likely introduce undesirable running characteristics (especially at idle) due to the configuration of the cylinder head, direct injector, and piston. It's a delicate "balancing act".... but a fantastic system! The Optimax is certainly one of the most "impressive" improvements to 2-stroke technology that I've seen during my career!