Manual Boost Control on a RzR

[Sparky]

Brad -- --

I'm considering a Big Bore and Stroked "Kit" for my Rzr. This will raise the CC to 902.

I'm considering also the possibility of a manual Boost controller instead of the current spring Boost controller. I envision some type of knob affair that I can incorporate on the dash. What have you got ??

Also - How does the Turbo map out for this larger engine -- Will the Turbo go up to 30 PSI or are we out of it's efficiency profile ??

Also - Have you folks worked with a rising rate fuel regulator ?? If so - Have you put together a "Kit" ??

And - Have you swapped out the factory fuel injectors for higher flowing ones - If so ..... Any thoughts ??

I'm also exploring the possibility of adapting the Aerocharger to the Weber -- A bored and stroked 850 .. ..

As you see -- I've to much time on my hands .. .. ..

Dave

[Andrew]

If you are going to build the engine in the rzr you will need a different trim Aerocharger. The 64/150 that we included with the kit is perfectly sized for the stock engine but it is too small for a 900cc engine. If you simply stroke the engine to a true 800cc engine and run the rev limiter at 7000rpms, I would use a 72/150 53 series Aerocharger. If you go to the 900cc big bore and stroked engine you will need to step up to a 90/200 53 series Aerocharger. Both of these turbos will bolt directly in place of the current Aerocharger. On either unit I would not suggest running more then 25psi.

We tested a rising rate regulator during the development of the kit and actually include them in other kits that we produce. If you are looking to run a regulator, I only suggest that you use a Aeromotive compact regulator as many of the other companies make an inferior product. Brand "H" is notorious for missing parts from the factory.

Swapping out the factory injectors will require an entirely new fuel controller, so that you can pull fuel from the factory ECU map during idle and low rpm running.

For the Weber I would also suggest a 72/150 or 90/200 depending upon what boost level you want to run.

[Sparky]

And to clarify --

The 64/150 can't be upgraded/re-built .. One needs to purchase the larger flowing 90/200 53 then for a 900 Polaris motor ??

A few more questions -- Controlling Boost .. ..

What are the options for controlling the Boost from inside the vehicle ?? I want to eliminate the spring/shim Turbo Boost Controller .............

Your kit's fueling box -- What is the maximum boost the box will handle ??

Upgrading the fuel pump and using a rising rate fuel regulator -- Are you going to put together an upgraded fuel system that one can order in the near future ?? If not -- Any direction for correct part numbers and vendors ?? I see Mountain West does offer a complete upgraded fuel kit - For their Supercharger system.

Just thing out loud .......... On the throttle body -- I've the early style that required JB welding your adapter to -- I'm considering getting a late model throttle body and having it machined larger -- This will require your later model adapter -- Do you see any problems in this area ??

Do you see any other roadblocks on using your Aerocharger Turbo system on the 900 cc Polaris engine ??

Thanks ........

Dave

[Collin]

Dave,

The 64/150 was sized specifically for the stock RZR motor. When you start talking about upping the cc's to 900 you are effectively increasing the size of the motor by over 18%. Though the turbo you have would physically work, it will not be the most efficient for a big bore kit with 7000+ redline because the change results in a 80% increase in airflow. Here are a few examples:

(all the below is figured with our compressor calculator which has proven to be accurate compared to stock RZR and standard Aerocharged RZR dyno results)

Stock Aerocharged RZR:
Engine Size: 49in^3
Engine Speed: 6000rpm
Air/Fuel Ratio: 11.8
Outlet Pressure: 6psi
Intercooler Effectiveness: 70%
Comp. Pressure Ratio: 1.41
Air Flow Volume: 95cfm
Engine Power: 83hp
Required Turbo: 64/150 - This turbo also allows for a large safety margin and plenty of room for the operator to turn up the boost.

Your 900cc kit
Engine Size: 55in^3
Engine RPM: 7000rpm
Air/Fuel Ratio: 11.8
Outlet Pressure: 15psi
Intercooler Effectiveness: 70%
Comp. Pressure Ratio: 2.02
Air Flow Volume: 171cfm
Engine Power: ~149hp

Now 149hp is quite a lot for a RZR. If you think yours is fast now then get ready for the first time you summon over 60 more horsepower in a vehicle the size of a RZR. Consider this however, there is room to advance your current kit to these levels without needing to up the cc's Example:

Aerocharger kit with Dynatek, Air/water intercooler, & raised boost
Engine Size: 49in^3
Engine RPM: 7000rpm
Air/Fuel Ratio: 11.8
Outlet Pressure: 15psi
Intercooler Effectiveness: 80%
Comp. Pressure Ratio: 1.83
Air Flow Volume: 141cfm
Engine Power: ~135hp

We are running the above setup at ~11psi currently with stock rzr kit fuel system with stock pressure! We need to up the boost and get it back to the dyno. We will also be experimenting with upgraded pump, rising rate regulator, and custom timing maps via the Dynatek box to see how much higher we can go over the above numbers. Bottom line is that you could upgrade you existing kit and get similar results or you could tear into your engine to do a big bore kit for $4k which would require a different Aerocharger, or do an engine swap for over $8k. The weber makes is advertised to make 130hp even though Weber's technical site says it makes 104hp, the ecu is also said to be limited to about 15psi.

Compressor maps for all the aforementioned Aerochargers can be found here:
http://aerocharger.com/aerochargers.php

You can run a boost controller if you like. Set the Aerocharger to your desired low boost setting then use your manual or electronic boost controller for your high boost setting. Essentially all the boost controller is doing is bleeding off an amount of air that tricks the turbo into thinking it hasn't hit max boost yet.

As for the throttle body adapter that shouldn't be a problem as boring out a throttle body will only change the inside dimensions. You would need to bore out the throttle body adapter to take full advantage of the new TB.

[Sparky]

Collin/Andrew --

A couple of months have passed - And much has taken place ............

In a few days I'll be picking up my 902 motor. This motor is slightly different than what is currently offered - I won't go into detail but do have 2 specific questions .. ..

The stock Polaris injectors are 18.25 Lbs per hour at 43.5 PSI fuel pressure. At 80% duty cycle each injector produces 45 HP. At 95% duty cycle each produce 53.4 HP.

I'm looking for a replacement injector that will produce appx 55 HP at perhaps 60 % duty cycle.

Any leads ?? Also will have to have the Polaris harness.

I also want to run a different fuel pump and rising rate regulator. I've some canditates in mind -- How bout you ??

I also have to have a Boost signal for the regulator -- Do you see any problem with Teeing into the Fuel Box Boost line ??

If all else fails - I'll just add a stock 4th injector as this will get me to the 200 HP mark on fuel.

On paper the new engine pencils out at 209 HP -- The one real roadblock is the rather poor flowing head. Mine's port/polished with 2mm over valves - And this only helps slightly with flow. Realistically we are shooting for 165 hp.

[Sparky]

One cannot make long posts on your BBS -- Got cutoff on my above post !!

I'll have to call shortly and order another Turbo and your larger Donaldson filter along with a few other parts.

One other thing -- I've been plagued this winter with blowing out the exhaust doughnuts and I have Holz engine mounts so the drive train assembly doesn't have virtually any movement. My question is - With my new motor running at twice the Boost I'm now running (11 PSI) and a larger volume of exhaust -- Is there any other material for the exhaust doughnuts ?? I'm looking for something that will not flake apart and completely seal.

I'd rather not re-invent the wheel -- If you have any thoughts on any aspect on the 902 .. Pass um along to me.

Appreciate it .......

Dave