Semi-DIY Mild Engine Build for FI

Hi Dave, good to hear from you and I appreciate your offer.

However, on the design I am using, the Aerocharger won't be a choke point. I have intake and exhaust valves enroute overseas from an OEM supplier in order to accomodate this arrangement:

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That's why I said in my previous post that I had to make some assumptions on valve cracking dP and opening rate... and potentially why I have a big dip in mid-range torque. I won't know for sure until I fab everything up and actually test it.

I would also like to make everything as simple and passive as possible. I also have tried to make this a "fail-safe" design in case there are issues with the vain controller, exhaust valve, and intake valve sticking. One of the ways to do this was complicate it a bit more with BCSV, wastegate, etc.

Glad to hear you've had experience on compound setups - now I know who to contact first when I get ready to tune it!

Dave

Looks like a Sequential Semi Compounded setup. What is your larger turbo going to be, and what pressure ratios will you be running on each turbo?
 
Dave - I erroneously said the Aerocharger was the LP turbo. I meant to call it the Low Flow (LF) turbo. That's where the confusion came from in this hybrid concept.


What is your larger turbo going to be, and what pressure ratios will you be running on each turbo?

I need a constant PR of just over 2 to get the previous curve. Problem is the turbine and compressor variables for two turbos. Getting them to overlap is difficult - especially for the LF turbo.

If I stick with the Aerocharger LF, only the 66 series LF designs can get to 2ish PR. The wide turbine AR on the Aerocharger is nice though to work with.
 
DLC-coated wrist pins after discussion with piston and coating reps. No need to weaken the titanium rod further by drilling the stressed small end for a bushing. Bushing insertion can also sometimes screw up the soft titanium. Rod small and big end bores are checked for parallelism. Re-worked mains caps good for 600 WHP. Wife was amused that I got the NSX some "diamond parts."

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Thanks to Mr. Dan Benson for this awesome block:

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Waiting for the new OEM oil pump housing and gear to come back from Fuji's Wonder Process Craft (WPC) treatment. Mainly to strengthen the gear with the micro peening. I had already slightly radiused the gear edges - they were razor-edge sharp with a lot of potential stress risers. The SOS and Dali oil gears have more of a radius on them, so I'm confident oil pressure will still be higher than those.

A lot more tricks to come on the total rework of the oil pump housing, elimination of the OEM cooler, addition of a custom automatically-adjustable oil/water cooler, and custom Accusump. The goal is to reduce pressure drop through all this stuff to less than the restrictive OEM setup so as to minimize pumping power and heat added to the oil. Just 1/2 a qt of this special alumina-epoxy to reshape the new OEM oil pump housing was $250 from an overseas supplier after extensive investigation to a product that can take continuous submergence to oil at up to 400F. Still a lot cheaper and more reliable than a dry-sump setup.

Dave
 
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that looks awesome (how many times have i said that on this thread?)

very interested to hear about your oil pump improvements. surprised you decided to do the wpc actually :)

Thanks. It's too bad I'm "rebuilding" my rebuild, but I'd rather spend the time and money now instead of redoing this again later.

As much as I've written about it previously and doubted it for engine bearings, piston rings, and cylinder walls, I decided to do the WPC primarily for the peening effect on our oil pump gear to strengthen the surface a bit. Besides it and the housing (and relief valve), that's all I'm having done :smile:
 
This passive compressor bypass valve will be flow tested to measure pressure drop at various flows up to 600 scfm (8500 RPM). The valve has been flow-optimized. The inlet nozzle and exit design is pretty cool. Spendy though - hope I need just this one.

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Still working on the turbine bypass valve design to get a good seal for my low-flow turbine at low RPM.
 
This passive compressor bypass valve will be flow tested to measure pressure drop at various flows up to 600 scfm (8500 RPM). The valve has been flow-optimized. The inlet nozzle and exit design is pretty cool. Spendy though - hope I need just this one.

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Still working on the turbine bypass valve design to get a good seal for my low-flow turbine at low RPM.

Why not use wastegates?
 
I will use one wastegate just upstream of the high flow turbo. However, a simple swing checkvalve with linkage to a pneumatic actuator would provide the response, durability, and sealing required to ensure exhaust flow at low RPM is all directed to the small turbo.

I'm balancing passive designs and fail-safe positions into this as I'm going with a goal in mind to protect this engine. I'd rather not tear into it again if I can avoid it!

Dave

- - - Updated - - -

From my torque plot previously, up until around 4500 RPM, turbine control is through the variable turbine geometry vanes themselves.

From 4500 RPM to around 5500 RPM, turbine control is through the VTG vanes and the small turbine bypass valve.

Above 5500 RPM, large turbine control is with the wastegate.
 
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Per many PMs/request I'm going to share the receipt/work order.

There are 2 versions (original and me using my Jedi powers to get the price down - since I'm good at befriending the dude).

The shop that did my NSX engine is up for sale. If it's not sold they will probably close the doors next month. The shop has tons of business, but the new owners treated their main and best engine builder like shit and he was fed up and jumped ship to a competitorshop (not far from Apple HQ) that did my GTO (my first piston engine build).

I was told by my NSX engine builder that thanks to my youtube videos they are getting too much business at the Ellsworth location.
 

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Attached are my receipts.

Please keep this confidential. ;)
 

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How did you get those SOS discounts?!

20% off their carbon clutch? Jeez, I spent almost $5k with them on my build, asked for a free shirt and they charged me for it :mad:

I will NEVER buy anything from them again.
 
How did you get those SOS discounts?!

20% off their carbon clutch? Jeez, I spent almost $5k with them on my build, asked for a free shirt and they charged me for it :mad:

I will NEVER buy anything from them again.

I think my parts were bought around the time they had their end of year specials and/or it was a discount to a engine build shop ( I had to produce documents and photos to support this claim).

http://www.scienceofspeed.com/newsletter/2013-11-29/ScienceofSpeed End of Year Sale - NSX.pdf
 
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A bit of an update.... I finally have 10k miles on the rebuilt engine. Unfortunately the car sits a lot now. I'd like to get it back to more of a daily-driver and have taken off the dry sump and custom twin turbos. Dry sump reliability scares me, and the semi-sequential semi-compounded turbo tuning wasn't going all that great for normal daily driving. Full throttle is awesome having 15 psi of boost from 2500 - 7500 RPM, but the swap between my Aerocharger and B/W EFR 7670 just wasn't happening well. I just don't have the time or money to dump into trying different turbos at this point. N/A is quick enough on the street for me.

Anyways, a question in another thread about the DLC-coated piston wrist pins I did has prompted me to post a few pics from one of my other neat mods - the custom oil filtration and oil cooler setup I made a few years ago. Specifically the filter. It's a Canton CM-45 inline oil filter with replaceable cartridges. It's a high-flow, low restriction design for racing applications, and uses a synthetic filtration media. It's also easy to take apart and examine what it filtered.

I contemplated changing it within a few hundred miles of the rebuild, but decided not to because I thought I was pretty anal about keeping everything clean. I pressure-washed the block and oil passageways countless times, along with the crank gallery, heads, etc. So, I relied on the filter to stand up to it's recommended 10k mile oil change intervals. I did go through four oil changes... the initial 30wt non-detergent startup oil, then about 600 miles on Joe Gibbs break-in oil, and then finally a few rounds of non-synthetic stuff. My dry sump setup had a magnetized drain plug, and that stayed relatively clean considering the ferrous piston wall/ring break-in.

So, this is the old filter media, and then taken apart. There are just a few aluminum specks, probably from the extensive block work I did (Benson sleeves, Timeserting, etc). There were also a few non-magnetic salmon-colored specks too. I built the motor and I have no idea where those could have come from. :confused: Anyways, as part of my Spring startup ritual now, I changed the oil, pulled the plugs to crank it over and build oil pressure without a major load on the crank and rod bearings, and then I did a compression test. All cylinders were great. The thing runs fantastic.

I highly recommend this filter if anyone else is doing a custom oil setup. This uses 12AN fittings and lines.

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I Just wanted to update that the engine build has been great.

Last week I had the SOS Flex Fuel conversion kit installed and tuned.

At 13PSI on a mix of 70% E85 and 30% pump gas I made 467rwhp during a 85F summer night.

That was at 7900RPM. Had the tuner hit redline it would have easily hit 480rwhp.

Dam car is a beast..... and pulls harder than the 600HP tuned F458 that I drove earlier in the year.

Oh and I forgot to mention those power numbers are with cats on and a dirty K&N air filter.

Wouldnʻt be unreasonable to assume that with no change in boost, all the way to redline, cleaned K&N, full open exhaust and in the winter, I may be at 500RWHP which (with a 14% drivetrain loss for the NSX manual) I would have near identical HP as a McLaren 570S and 2nd Gen NSX......
 
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^ What was your numbers prior to E85?
 
That's a pretty damn nice gain. I am curious though why your built for boost motor with a aftercooler and running 13 psi only yielded 430? Cause I was hoping to hit that number on 10 psi when my motor is done and that is without an aftercooler on Aem series 2.
 
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