finalturismo

My openport should be in soon, was wondering if anyone has had any experience with tuning the car for SSV removal.


Iam thinking about doing the following
Remove Airpump and disable in ECU
Block Off EGR on manifold
Block Off SSV and disable in ECU
Install Headers
Install 170F thermostat
Have fans kick on at 175-180F
Increase Oil injection for low RPMs

From what i have heard removing the SSV can hurt low RPM performance and Increase performance a bit at higher RPMS.
In-reality cant a tune be done for SSV removal?

dannobre

iTrader: (3)

No reason to remove it. You can play with when it opens but you won't find much

finalturismo

I just want to clean as many unneeded parts out of the engine as possible and simplify operation.
Thinking a tune can adjust for absence of SSV at low RPMs. I don't see it serving much of a purpose besides restriction and emissions. I cant see how this wouldn't help with a proper tune? but i am new to the RX8 world.

So the airflow rate at lower RPMs would be higher, cause the car to run too rich and have a rough idle without a tune i am guessing?

With a proper tune couldn't you adjust for the increase air intake at low RPM?

Looking for some experienced tuners and dyno run arguments.

I don't like the idea of a vacuum line choosing when to open a value in the intake.

dannobre

iTrader: (3)

Getting rid of the SSV will drastically lower the intake velocity at lower rpms... there isn't a flow problem there unless you go FI

You will loose deleting it NA in every regard

Mazda did a pretty good job with the intake tuning

You can make gains with AFR changed and timing and if you port the motor and change the exhaust and intake... but this isn't a motor that has a lot left on the table

TeamRX8

iTrader: (25)

A. You don’t “remove” it. It needs to be wired opened. Otherwise if it’s removed there’s a big open cavity in the flow path that’s going to create turbulence and hurt flow in all conditions.

B. When it’s wired open none of that other stuff matters as far as the SSV is concerned. You will lose a lot of lowend response below 4000 rpm. Unless this is a dedicated track car that typically won’t see engine speed below 4,000 rpm on track this is a bad idea. Your post indicates a general lack of understanding. Whether you like it or not is irrelevant. It isn’t going to help anything at all.

jcbrx8

I concur completely w/ Dannobre & Team... you're K.I.S.S. mentality is generally admirable, but mis-applied here.

The LIM valve driven expansion & contraction of the intake system is both effective and elegant engineering design. Disabling it will be unhelpful,...even harmful b/c performance depends on a) volume AND b) flow velocity. You can compensate for the increased volume at low rpms via tuning,...but you can not for the reduced flow velocity... which is physically /mechanically determined.

Rethink it...

finalturismo

This is about the same data and arguments i came up with when i did a quick forum search before. Yes i do have a lack of understanding that's why i am posting here to data mine. But i have a good understanding of how stuff works

I need as much data on that statement as possible, i understand that it loses response at low RPM. I want the absolute reasoning as to why. Does this occur because the engine needs resistance in airflow at low rpm to produce power more efficiently? Is it because the air / fuel maps are in line with emissions stands. The 13B-MSP was totally designed with emissions as one of Mazda's primary attributes for this car.
I am aware of the negative impacts of removing it stock, although i did not know about the air turbulence part. Let me pick your brain for a bit, can we get into detail a bit about losing power below 4,000 RPM and why this occurs? I see many of FI users that do a custom intake manifold remove it all together. What if the car is properly tuned for the amount of air coming in at low RPM, but not with a turbo or stock intake manifold. I am also aware that getting this engine past 400HP, is not reliable.
Data please, trying to learn here.

Loki

iTrader: (1)

Power production is a function of intake air speed and mass flow. An intake,on any engine, is designed to supply the engine with air all the way up to its redline. On the Renesis that's about 200g/second.

However, when you're not at redline, which is most of the time, you don't need as much as air, so air will move through the intake more slowly. Slow air is bad because it doesn't mix with fuel as well and doesn't fill the cylinder/rotor face with the same characteristics they were designed for.

So everything involved in intake design boils down to how to keep air moving at the optimal velocity at different engine speeds and flow volumes. All 3 intake valves are part of that. The SSV is closed below 3500 to constrict the intake air path and force air to go faster. If you remove it: slow air, poor filling, poor fuel mix, poor power.

TeamRX8

iTrader: (25)

just because, that’s why ...

.

Brettus

iTrader: (2)

Air has momentum , a small pipe with higher velocity air will fill the chamber better than a larger pipe with low velocity ...right up to the point where the pipe diameter becomes restrictive to flow .

finalturismo

Ok thanks, that's the answer i was looking for, whats a good aftermarket manifold i can put on this bugger that would sustain boost in the future?

Brettus

iTrader: (2)

The stock manifold works just fine with some tweaks :
*Disable VDI ...... some leave it , but I have seen the dynos and you do lose a little by leaving it operational. I wired mine shut and removed the actuator.
*Alter APV timing ...... a few hundred rpm earlier max. only reason you need to change it is because engine in gear acceleration is so much faster than N/A and the movement of the valve is quite slow.
*Alter SSV timing ...... I open it a bit later than stock and get a slight spoolup improvemet by doing so . Not a biggie to leave as is though.
*Upgrade injectors ...... see my injector upgrade thread.
*cable tie on Jet air hose -both ends ..... to stop it blowing off the first time it sees boost . Wouldn't hurt to remove it but I left mine in place ...affects fuel economy at idle.
*Give it a good clean and shield any parts in close proximity to exhaust /turbo.

As far as the plastic UIM goes I still have one but It's my 2nd one after the first one split on the welds - that was after 10yrs though. If you like bling and don't want that chance of a crack ...Turblown is producing one for just over $1000
Otherwise just make sure all the hoses off it are cable tied and it's good to go.

finalturismo

Thanks for the good info, the only negative thing i saw is the fact a metal manifold is $1000+ ..............

Brettus do you happen to have Skype or Discord, your just the person i need to pick their brain a bit.