To clarify:

It was neither crankshaft nor camshaft sensor signal noise.

It was mechanical signal noise to the MAP and FPR, both of which come off the same port on the throttle body. Get a change in both MAP signal and fuel pressure, and you'll see changes in output.

This is the first time we've seen this phenomenon so exaggerated on a 930. Maybe it's because the ECU processor and sampling rate is much faster than on other ECUs? Maybe it's just reversion that combination of parts (CR + stock ports + 964 cams + headers + small turbo etc)? Maybe it's just because of where the signal was taken from, at the throttle body?

We've seen this on Supras on the dyno, and if the MAP signal is measured in turn at each of the four different ports on the manifold, you get noise at different RPMs.

Regardless, filtering smoothed it out considerably, and by the time the larger GTX35R turbo was fitted, it was pretty much a non-issue.

Here are final from the GTX30R dyno tests, wastegate only vs. boost control activated.

http://forums.pelicanparts.com/uploa...1465838394.jpg

http://forums.pelicanparts.com/uploa...1465838426.jpg

http://forums.pelicanparts.com/uploa...1465838440.jpg

A local automotive machine shop.
New valves, guides, stem seals, springs & retainers.
Least amount of surfacing.
No porting or polishing.

Is that spool below 3000 rpms just the smoothing of graph? Anxiously waiting the GTX35R comparo graphs.

That's a huge difference. This is just due to having the boost control activated? So w/o the boost control dumping the WG signal the WG was leaking?

What turbine housing?

30r looks like a pretty fun setup. I never would have guessed the spring controlled waste gate would compromise boost build so severely.

Gentlemen's bet for the 35: Im gonna go with 468.3 whp

My spring allows full boost .8bar by 2900 rpm. His spring is soft or that turbo overcomes it somehow and lessens the response.
I use a gt3076r on a 3.0 6.5/1 930 engine. If my engine can get quick boost his will get quicker. Is there something I'm missing?

Are you efi and dyno mapped? Lower timing would spool faster but torque may be down. Header split desing would also effect spool.

IIRC that 45mm wastegate had a low pressure spring in it.

The headers' WG circuit wasn't ideal -- nor were the collectors for that matter -- but the price was right and you make the most of what you've got to work with.

I saw the new vid....
I'm really glad someone has done this turbo comparo.
But in the end it just makes sense to listen to the pro's. Chris has been saying it all along, Get the gt35r for the 3.3-3.6 engines.

<iframe width="853" height="480" src="https://www.youtube.com/embed/Pg_Dp_j9li4" frameborder="0" allowfullscreen></iframe>
Sorry if I jumped the gun

Nice! Are the GTX35s on backorder now this video has gone live? ;)

Very strong numbers. This is still on stock port 930 heads and pancake??

Yes, stock heads with stock valves, untouched 930 flat manifold.

Very nice!!

So does the poor WG design affect total flow if one shoots for higher PSI anyway? I cant see that in the graphs.

Impressive numbers! Great considering how close the setup is to mine. Maybe I missed it, but is this on 91 octane?

Yes, 91 octane. Impressive. So which turbo for this same engine but CIS and SC cams with '79 fuel head, adjustable WUR with RPM switch, .9 bar spring? Fuel will limit to 375 RWHP or so? I would think the HP and TQ curves for both would be very close? Great video, thanks.

What size spring? 1 bar or 1.2 bar?

Higher the boost should result in more airflow through turbine and less through WG circuit.

I mean, would better wg design result in higher hp or not. It migh give bad turbulence or something else.

Well, this is my theory. If you have back pressure from a restrictive WG circuit, your boost rises slightly higher than desired boost levels negating hp loss from said restriction.

Dr. Chris, Dr. GJF, your thoughts?