Compound boost: EFR 7670 into Coldside FFS W/ H20/Meth into 10.5:1 VVT Built Engine
 

Cause someone had to do it.

Currently turbo'd with EFR 7670 at 16 PSI, MS2E engine management.

New setup will be EFR 7670, intercooled with intercooler mounted flush with undertray and a pair of fans mounted on it (hidden but gets clean air), then going into a FFS coldside running a 130/65 pulley. Probably spray water meth right into inlet of blower. Probably gonna spray a LOT. And then to a built 10.5:1 VVT motor. Running on a MS3 Pro with IGN-1A Race coils and 36-1 triggerwheel in factory location with stock crank/cam sensors. Hope to run on 93 octane, but will switch to E85 if I have to.

Already built the engine, EFR 7670 installed. Motor revs to 8700-8800, makes good power, but is laggy from turbo being too big. Gotta move intercooler and build ducting/fan setup for it. Already ordered a MS3 Pro and wiring stuff to rewire engine. Ordered a AEM water/meth progressive kit. Bought a used FFS coldside off of 18psi (thanks!) and ordered the 130mm pulley for it.

Pics of motor build and current setup:

Trubo
https://www.miataturbo.net/attachmen...ine=1373995754

https://www.miataturbo.net/attachmen...ine=1373995754

https://www.miataturbo.net/attachmen...ine=1373995754

https://www.miataturbo.net/attachmen...ine=1373995754

https://www.miataturbo.net/attachmen...ine=1373995754

https://www.miataturbo.net/attachmen...ine=1373995754

https://www.miataturbo.net/attachmen...ine=1373995754

https://www.miataturbo.net/attachmen...ine=1373995754

https://www.miataturbo.net/attachmen...ine=1373995754

https://www.miataturbo.net/attachmen...ine=1373995754

https://www.miataturbo.net/attachmen...ine=1373995754

https://www.miataturbo.net/attachmen...ine=1373995754

https://www.miataturbo.net/attachmen...ine=1373995754

https://www.miataturbo.net/attachmen...ine=1373995754

https://www.miataturbo.net/attachmen...ine=1373995754

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1st :party:

That's not why its laggy.

Why is it laggy then?

:rly:

Then why isn't it making full boost sooner?

In for winning. Glad someone bought that FFS on vlad and is going to use it the right way!

Because you touch yourself at night.

Because of the tune and setup.

Log exhaust manifold. Stock NB2 intake manifold.

"high to mid 9's at full boost" - that's like fouling plugs, 25% power drop rich.

"Ignition timing I won't say but lets say LOW" - that's a great way to skyrocket EGT (especially combined with super-rich fuel)

No mention of boost control (wastegate? ebc?) or VVT tuning :rolleyes:

etc etc

Turbo sizing has a lot to do with it, but in this case it's just a dumb setup & tune.

If you are suggesting my current tune is not ideal, you're crazy!!!!

I kid. Obviously it sucks, I mentioned I tuned it that way to keep it safe (10.5:1 comp, sky-high AITs, no vvt). I know if I tuned it 11:1 and give it more timing I couldn't have made 35 passes at the track without a failure. I can tune a miata, been doing it for 6 years or so. :) It's rich and retarded now to keep my high comp motor safe till I get the setup finished. IE, it's not finished. :)

And my NB intake manifold is ANYTHING but stock. :)

11:1 is still super rich

you built a motor with stock pistons. now you're working around it to make up for the shortcomings of the motor and blaming it on the turbo being "too big"

while this guy has 30psi from a GT35R at ~5200rpm. You make 6psi from a better spooling turbo at 6200rpm.

https://www.miataturbo.net/attachmen...ine=1373999051

Fix your tune.
Fix your setup.

Really? You came here to tell me 9.5:1 is too rich? What are the shortcommings of my engine again? Besides having 250 in the shortblock.

If your engine can't handle 11:1 afr - that would be a shortcoming.

I dunno if it can run 11:1 with 168*F AITs while still breaking it in. Not gonna find out either! I would rather drive it than blow the motor again. I didn't exactly plan to have super high AITs, gotta change my IC setup.

Why you all over my case anyways? Other than stating the obvious. 9.5:1 is rich, 168*F is hot, no timing is not ideal, etc? Things are changing, see first post!

I would be stupid to tune it aggressive when there are problems with the setup (igition pickup issues, AIT issues, wideband at one point, had a tiny boost leak I found too).

Yeap, it's gonna be sweet! I think this is the 18 PSI pulley I bought, so should improve low end torque a bit and help spool the turbo sooner too. Win-Win. (Que someone to tell me I'm increasing the cost and complexity!)

who made that log manifold?

It's an FM manifold modified to T3 bolt pattern and opening, and a pipe welded on w/ 4 braces to support a 38mm wastegate. I made it T3 and made the pipe piece, had an old man TIG it on with a high-nickel filler. Been solid so far and cheap!

So I'm trying to conceptualize this but not real familiar with superchargers. Do they provide a max psi of some sort or will they always provide a constant delta P, So raising the inlet pressure will then directly relate to a raise in outlet pressure from the supercharger? or will the turbocharger just start the supercharger closer to its max target pressure?

Will the turbo not create drag from the supercharger suction at low rpm, then the supercharger just act as a restriction for the turbocharger at higher rpms?

The engine is an air pump. Mine is a 1.8L air pump.

The SC is an air pump. With a 130/65 pulley setup, it will turn two times every time the crank turns once. Motor moves 1.8L of air in 2 revolutions. So the SC will spin 4 times, each time moving 62 cubic inches of air, which is about 4L worth of air.

So blower tried to push 4L of air into a motor that only asked for 1.8L. Bam, boost.

Same story with the turbo blowing into the SC. Only there isn't a 2:1 or 4:1 simple ratio to explain it. At some engine speed, the motor is going to spool up the turbo and the SC will be sucking in 4L of air per 2 revs of the motor, and the turbo is going to blow in more than that into the inlet, boosting the inlet pressure.

Basically it will drive like a SC car down low, and take off up top when the turbo spools.

Yeah I get that, I guess I was just looking at it as what happens when one is out performing the other? will the less performing charger not create a drag reducing the performance of each system if it was running independently? Or is that negligible due to the performance gain? So even a supercharger running at half of its normal efficiency due to the turbo creating drag at low rpms would still be better than no supercharger at all I guess. Or will the supercharger suction just cause the turbo to spool up faster and not really allow much drag from the turbo?

Just thinking out loud here

Either way im excited to see what happens.

So what is the timeline for this shiz? I want to know when to check back.