Honda 1.8L on RV6A Now Flying!

[rv6ejguy]

I'm using a TO4E-50 compressor and T3, stage 3 turbine wheel in a .82 housing. We've used this on a couple of RV turbos with 160-225hp and it's a good match. With your 1800cc, I'd drop down on the turbine a/r to .63 but a similar sized compressor would be needed at 175hp.

Most people match turbos wrong and many spreadsheets are wrong too as they don't take density ratio into account at airplane altitudes. People blindly follow what others have done before them, not knowing enough to realize the errors.

Compressor inlet flow must be much higher at 10K to deliver the required mass flow at the 2.0 pressure ratio.

My compressor discharge temps confirm we're operating on the map where we should be.

I would not use a turbine wheel smaller than 2 inch exducer (minor diameter). Not sure if you can do that with T25 type flanges. Haven't checked what you can get in the GT series turbos but you may have to mix and match turbo frame parts to get a proper match of turbine and compressor like I did.

[charosenz]

Originally Posted by rv6ejguy

I'm using a TO4E-50 compressor and T3, stage 3 turbine while in a .82 housing. We've used this on a couple of RV turbos with 160-225hp and it's a good match. With your 1800cc, I'd drop down on the turbine a/r to .63 but a similar sized compressor would be needed at 175hp.

Most people match turbos wrong and many spreadsheets are wrong too as they don't take density ratio into account at airplane altitudes. People blindly follow what others have done before them, not knowing enough to realize the errors.

Compressor inlet flow must be much higher at 10K to deliver the required mass flow at the 2.0 pressure ratio.

My compressor discharge temps confirm we're operating on the map where we should be.

I would not use a turbine wheel smaller than 2 inch exducer (minor diameter). Not sure if you can do that with T25 type flanges. Haven't checked what you can get in the GT series turbos but you may have to mix and match turbo frame parts to get a proper match of turbine and compressor like I did.

Ross,

That is very good information and I appreciate you sharing that. I am looking to for less HP. I think 180HP is a good safe number to shoot for with this engine. Plenty for what I am looking for.

You are certainly welcome to post pics of your turbo set up in this thread if you have time, I would like to see it and I suspect so would other readers.....but I know you are quite busy.....

Yes, calculators are what they are. The Matchbot calc is good and bad. Good because it is one of the few calculators that incorporate the changes in altitude for different set ups. But it is biased in that it automatically inserts boost based on the particular BW turbo it thinks you need - which may or may not really be the boost you are looking for. (like in my last link).

I am not sure if you had a chance to look at the pic of my exhaust set up, but I am not opposed to welding up a honda to T3 flange adapter like the Honda to T25 flange that is shown....

The next step in my set up is to do some accurate fuel consumption measurements at WOT to calibrate the FF# setting in the programmer.

Charlie.

[rv6ejguy]

Many calculators also underestimate engine mass flow by using unrealistic or arbitrary VE values. I base mine on hp which is overall more accurate.

Even a lot of the Reno Sport Class folks are doing it wrong IMO.

The T3 flange will open up some larger matching turbines for you. There is no sense in having a tiny turbine wheel on an application which is not at low rpms, is usually at high load and does not demand fast response. It's very different from automotive in that respect. The larger wheel is much more efficient here than a small one and should give better BSFCs everywhere and more power with less manifold pressure.



Here's a shot of my intercooler. The turbo is buried aft of the engine, I'll try to dig up a photo from the top. That might take a bit, we're working 7 days a week right now to keep up with orders. It's snowing again here anyway. Might as well be at work...

If you're running down around 135hp in cruise, be sure to look at the surge margins up high at the lower pressure ratios. The TO4E-50 compressor has a very wide operating range which works well in my case. It's a great match at low power and high and high and low altitudes too.

[rv6ejguy]

Here are a couple pix of the same turbo on an STi engine in an RV7.





My turbo is high mounted to avoid the use of the scavenge pump required on this installation.

We're both using the integral wastegate with a dual port actuator so we can easily change the manifold pressure from the cockpit.

Notice the strong mount to support the turbo here which is critical to reliability. Also consider exhaust slip joints to reduce mechanical loads on the exhaust pipes from differential expansion. I'd use 321 stainless for all the piping to the turbo, much more reliable than 304 at these temperatures.

[charosenz]

Ross,

That looks great. A lot going on in that ship! Thanks for sharing.

I have SS on order to weld up a new Honda to T3 flange adapter.

and I am glad that I only have one exhaust to work with..

Charlie

[rv6ejguy]

Yeah, plumbing on an opposed engine is a lot more of a challenge with a single turbo.

[charosenz]

https://onedrive.live.com/?v=photos&...photos&o=OneUp

Here is a pic of the "first fit" of my new T3T4 on the R18. The short adapter I welded up will work well for the test stand, but I will need to reduce the size of this to make it fit inside the Rv6A cowling.

Here is the side view.

https://onedrive.live.com/?v=photos&...photos&o=OneUp

It will be a few weekends before it is back up and running.

I am not sure why I am only getting links and not actual photos. I have followed the instructions to have photos appear but sorry, only links. If anyone has some insight on this please share...

Charlie

[charosenz]

Originally Posted by charosenz

https://onedrive.live.com/?v=photos&...photos&o=OneUp

Here is a pic of the "first fit" of my new T3T4 on the R18. The short adapter I welded up will work well for the test stand, but I will need to reduce the size of this to make it fit inside the Rv6A cowling.

Here is the side view.

https://onedrive.live.com/?v=photos&...photos&o=OneUp

It will be a few weekends before it is back up and running.

I am not sure why I am only getting links and not actual photos. I have followed the instructions to have photos appear but sorry, only links. If anyone has some insight on this please share...

Charlie

One more attempt at the photo download....



This one using google photos and not MS onedrive.....The URL is pasted in the post but no photo...weird....

[Snowflake]

Try using halie.com. It's designed for sharing photos through sites like this.

[charosenz]

Testing....

Thanks Snowflake, here are a few pics using halie.com

Top view of first fit of T3T4

This is resized down to 500 kb hope it works.



Here is the side view.