I'm looking for a little basic advice for fitting a small turbo to a single cylinder GY6 Dune Buggy engine.

I've fitted an Ecotron RHB31 ZV21 to a common GY6 engine. The engine was originally a carburated 150cc engine which i increased to 170cc and fitted fuel injection. All seems well so far.

The turbo is designed for small engines and the specs say it will produce between 7 and 12 PSI.

I tried lowering the compression with spacers between the barrel and crankcase with bad results, so my first question is what do i restrict the boost to?

I'm not too happy with the stock wastegate valve, would i be better off using a different adjustable wastegate?

Any other advice would be very welcome.

TIA

 

I think you will have difficulty getting that turbo to work, it is designed for engines in the 550-750 cc range which make 50-70 hp. Do your best to make it function as is and see if it will spool at all before you put a lot of time and resource into it.

No way to tell you what to reduce the boost to. Shave the piston or bore the jug deeper if you are really concerned about the compression.

 

Thanks for the reply BEN,
Looking at the Ecotron PDF manual, their data says this particular turbo is designed to fit engines from 125cc to 600cc, my engine is 170cc. I've seen several of these fitted to GY6 scooters on YouTube and I've also seen another fitted to a 150cc Dune Buggy where it produced just under 10 PSI of boost. I did try lowering the compression by fitting spacers between the barrel and the crank case but this wasn't very successful, there was no halfway between high pressure and low pressure in the cylinder, it either fired or became very difficult to start.

I just wondered if there was a safe maximum boost, the wastegate is non adjustable and i wondered if i would be better off fitting an adjustable wastegate to be on the safe side?

 

You need to retard ignition timing, you may be able to re-key the flywheel if it's magneto . Do you have access to e85? If so your going to be in good shape

 

Hi BEN,
The engine has fitted a MotoEFI fuel injection system very similar to the Megasquirt/Microsquirt EFI systems and actually uses an early version of their software. The timing is fully adjustable from within the software. E85 as in fuel? Yes, i had planned on using this with the engine.

 

Pop the turbo on and go then. The e85 will help deal with the compression.

 

Yep, E-85 will allow at least 15 psi on stock compression without detonation. Make sure you have a high quality head gasket.

 

Thanks for the information and help guys, its been really useful and appreciated.

One last question about the stock wastegate valve, should i leave it as is or change it for an adjustable wastegate?

 

leave it, run it, change it if necessary later.

 

But without knowing, how would i know if it should be changed? The only buggy ive seen this turbo fitted to pushed about 10 PSI, if the manual for the turbo is to be believed, the turbo pushes between 5 and 12 PSI. What do i look for apart from knocking and preignition to tell me things arent good and i know to reduce the boost?

 

Knock and the boost gauge are the best indicators. 12 psi should be very safe with E85. At this boost level an intercooler will be very beneficial to performance and knock.
Start with full load timing about 10 deg less than stock at 12psi boost.
Establish best-power timing on the dyno.
Advance it 4 or 5 degrees listening for knock.
If no knock, your best-power timing is safe.

 

It doesn't make sense to go to an adjustable wastegate until you know the stock one is not going to produce the pressure you are looking for. If you are unhappy after you run it then make the change.