Time to go Stage II!

[Alky V6]

The latest pics of the intake with all the o-ring grooving finished. Up to this point in the intake development, anyway.
The nitrous distribution blocks have been slightly repositioned to be better centered, and lowered just a little bit thanks to a pocket that I machined into the valley cover to accept the nitrous fuel solenoid.

 

[Alky V6]

The exhaust header adapters are finished except for the bolt pattern for the header flange.
Material for the header flanges (304SS), double slip merge collectors with V-band clamp flanges, a bellows, and some short transitions for the start of the primaries have been ordered.

 

[BlownV6]

Im impressed!! You get more done in one day than I get done in a year!! Your sorta pissin me off , I gotta go get something done. Mike

 

[czimpel]

Wow, that intake looks awesome, great job. Imagine if you had to buy something like that!

 

[Alky V6]

The exhaust header flange has been drawn up.

 

[Alky V6]

Im impressed!! You get more done in one day than I get done in a year!! Your sorta pissin me off , I gotta go get something done. Mike

Channel that anger and take it out on those heads.
Are you planning on making a rectangular port version of your billet heads? If so, I just might know of someone who's interested.

 

[Alky V6]

James, your unit is torn down.

 

[GNDriven]

Donnie, were the nitrous ports stick into the intake runner, is that an air tight fit? or does it have to be?

 

[TurboBuRick]

Beautiful work Donnie.

 

[Squid4life]

James, your unit is torn down.

Alright, should be able to come by at or just after lunch today. Thanks for the heads up!

 

[Alky V6]

Donnie, were the nitrous ports stick into the intake runner, is that an air tight fit? or does it have to be?

The nozzles have a section that incorporate a 1/16 npt on their bodies. You simply drill and tap a hole using a 1/16 npt tap. Then the nozzles simply screw into the holes. With thread sealer, the fitting is airtight.
Where I chose to install the nozzles is a little thicker due to a 3/8" radius fillet that I used along that area. That gave me plenty of material for tapping the holes and gave me a strong wall to support the nozzles. Actually, you can drill and tap through some pretty thin walls and still be able to install and have adequate support for the nozzles.

 

[Alky V6]

The engine sim that I use, Performance Trends Engine Analyzer Pro v3.9 has recently had an upgrade come available. Enterprise edition.
One of the new features that mainly caught my eye was the ability to build a complete turbocharger compressor map in the program rather than entering only a few specifications off of a compressor map. This should allow for better output results.
I went for the upgrade today, and can say that it is more accurate. The spool up characteristics of the output is much, much better.

 

[Reggie West]

So can you tailor the header lengths to optimize the turbo or will you be trying to spec a turbo to Comp turbo or someone else to match the motor?

 

[Alky V6]

So can you tailor the header lengths to optimize the turbo or will you be trying to spec a turbo to Comp turbo or someone else to match the motor?

The FI91X should be a much better match to this motor than it was to the Stage I configuration. I'm going to wait to see how this turbo works out before I start thinking about changing it out.
The lengths and diameters of the primaries AND secondary piping of the exhaust system will play a very large role in the power curve. This engine, according to the sim, is going to be very sensitive to exhaust back pressure, which does make sense seeing that a lot of the specs that I'm using will be treating this engine as if it were a N/A engine, thanks to the level of flow 'crossover' during the overlap period in the combustion chamber that this free breathing S510 turbine is going to afford me.
I'm going to be playing with some unorthodox specs so it will be interesting to see how things turn out.

 

[Alky V6]

To use the compressor map in the EAP sim, I have to convert lbs/min to cfm. I picked steps in cfm of 100. Multiply 100 cfm by .069 to get lbs/min. Instead of .069, some people use .076.
To get a more accurate output with the sim, it's best to be able to enter compressor map data as low as 1.0 pressure ratio. The S510 compressor map does not extend down to 1.0 PR, so I have to use a little imagination and guess how the compressor map efficiency islands might extend down to 1.0 PR.

 

[Alky V6]

Playing around with the upgraded sim. This screen shot is comparing two different calculations. The difference between the two is a 7 inch difference in the primary lengths of the exhaust headers. The longer primary length favors the midrange with a small sacrifice of top end power. At 5,750 rpm (anticipated launch rpm), a difference of 65 ft-lbs of torque.
Notice how the spool up is much smoother with the program using a full compressor map in the calculations.

 

[Alky V6]

This is what I came up with to finish off the S510 compressor map.

 

[norbs]

Looks like your turbo was WAY too big for your old combo...It may actually work for you now Numbers look good.

 

[Alky V6]

Here's an interesting comparison between my planned primary length and a 44 inch primary length. I ran this comparison because I've run across the recommendation of running a very long primary length on a Stage II BUICK V6 more than a few times in different books. The Powersource book is one.
You can see in this output that the longer primaries really pumped up the lower midrange rpm power levels. The trade off was a loss in high rpm output. But on a road course, how much peak hp do you really need? For certain types of racing, the trade off is very practical.
In my situation where I plan to launch the car at around 5700 rpm, the benefit of the long primaries has already waned, so the shorter primaries would be the better choice.

 

[Alky V6]

I used the engine sim to calculate an operating line (red) for my engine, and plotted it across the S510 compressor map using a .069 factor to convert cfm to lbs/min. This is the furthest to the left I can expect the operating line to lay on this compressor map.
If I were to use .074, .076 or .0807, other common conversion factors, instead of .069, it would simply move the operating line to the right a bit on the compressor map. Either way you look at it, this turbo should work quite nice with this engine, running very efficiently from 18 psi boost on up to over 45 with efficiency to spare, if this engine can push it that high. I'm expecting only 39-41.
Remember, this is only going to be a 228 cid engine.