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Discussion Starter #1
Hey guys, I have the greddy kit and I wanted to know If I were to retard my timing would I be able to boost more? I'm on the stock wastegate and I have tightened it and it spikes up to 8-9 psi however I dont let it go past 5-6 psi. Anyway I can safely boost the 8-9 psi without getting EMANAGE ? I'm on stock 1.6 injectors. Should I get the 1.8 injectors and retard my timing ? A couple of my friends who mod their cars religiously say that it is a good idea. Any help would be appreciated. Oh and btw only reason why I have it tightened is because there is MUCH less boost lag. I hit over 6 psi by 4K.
 

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here's a thought. assuming you already use higher octane...a simple mod to do to reduce the risk of detonation is also to use a colder heat range spark plug. in example...ngk plug zfr6...-11, or higher. but of course. if you're gonna be down at autozone, you might as well buy a timing light or borrow one from a friend.
 

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to run 8-9psi on a greddy kit safely, you'll need:

190hp walbro fuel pump
1.8 injectors
AFPR

miataturbo.net is another great forum for greddy users.
 

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Discussion Starter #8
thanks for the help so far guys. I already am a member at miataturbo.net however they told me to get big injectors emanage fuel pump and what not. There was this one guy that only had 1.8 injectors and was pushing 15 psi I think safely by retarding timing or something.
And as far as the AFPR isnt that the same thing as the vortech fueling system that connects to the fuel pressure regulator which gets more gas when you're in boost? Sorry for the million questions but I just need to know so I dont blow up stuff.....YET lol
 

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He was running 15psi safely because he was using an Emanage Blue to control both fuel and timing.

There are actually three ways to reduce the probability of knock at full load on a turbocharged engine: reduce boost, adjust the AFR to richer mixture, and retard ignition timing.

Detonation is caused when the temperature in the combustion chamber exceeds the temperature of the air/fuel mixture. When exceeded, the mixture goes bang. Not a good thing, regardless of power. Detonation is the engine killer, not necessarily power.

If a system is detonation free, regardless of boost, rich/lean, power, etc., it will not fail due to bad combustion. But one knocking at a 10:1 AFR (rich) fail in a heartbeat due to an obvious over-heated air charge (think 10psi without an intercooler).

You either need to retard your static timing, invest in a Bipes ACU or MSD box, or enrich your fuel mixture.

The Bipes ACU (Auxiliary Control Unit) dynamically retards the timing of your engine to protect it from detonation or knock. The ACU uses three input parameters to control the timing: Airflow, RPM, and Intake Temperature. You can pull a total of 14° of timing. Not only will you help protect against detonation, or you gain low-end power back if you keep your static timing at 10* or advanced. The Bipes is a proven device in NA, turbo and supercharged Miatas. Aftermarket ECU and ?piggyback? usually have this function built in.

The MSD Boost Control unit specifically designed for the Miata. The Bipes actually originated as a mod for this unit for added adjustability. They can still be had, but usually for the same price tag as the Bipes itself. The MSD unit retards the timing 3° per pound of boost pressure with no more that 6° of retard being allowed. When no boost pressure is present, the ignition runs at the factory timing. These settings are fixed and cannot be adjusted. With that said, you can still run your Miata advanced to 14° of timing and when it boost it will retard back to a safe 8°. If knock is still present then set your back a little. It's a little basic but it gets the job done.

To just plain retard you static timing, you'll just need a timing light and a 12mm wrench. But by doing this you'll suffer in low-end power.

You're also trying to boost way more than those injectors are suited for. At most you want to raise your fuel pressure to 100-110psi. Anymore and you risk damaging your OEM FPR, bursting fuel lines, locked injectors, and even most aftermarket fuel pumps cannot produce enough flow to the injectors past that point.

You're using the supplied Vortech FMU, which comes loaded with a 12:1 disc. So we can determine your fuel pressure at full boost with math!

[tab:b6f6e1b73a]12 (rise) x 8 (boost) + 50 (fuel pressure at 0 ~hg.) = 146psi of fuel in the rail at full boost.

What does this mean?
[tab:b6f6e1b73a]You're pushing your fuel system to the brink of failure.
[tab:b6f6e1b73a]You're demanding more fuel than most FPs can provide.
[tab:b6f6e1b73a]You're running lean due to lack of fuel

If you want to boost 8psi you need a ratio of gain that will reach a target of 100-110psi in the rail:

[tab:b6f6e1b73a]7 x 8 + 50 = 106psi

Then you need an injector that can flow enough fuel to support your HP

at 106psi of fuel your 1.6L injectors (203cc) can only support 150rwhp. Which on a GReddy kit is only about 5-6psi.

[tab:b6f6e1b73a](317 / 10.5) x .8 / .55 = 44BHP on each injector

at 106psi of fuel 1.8L injectors (265cc) can support 190rwhp. On a GReddy kit that's around 7-8psi. So they should suit your needs perfectly fine.

[tab:b6f6e1b73a](413 / 10.5) x .8 / .55 = 57BHP on each injector

So to finally answer your question, yes...getting 1.8L injectors, retarding timing, a 7:1 ratio FMU disc, and a Fuel Pump that can flow at least 27 Gal/hr. at 110psi will allow you to support 8psi. Plus I hope at that point you have an intercooler as your intake air temps will be about 100* above ambient in the manifold at that point and the amount of ignition retarding it will take to battle ping will cause your EGTs to skyrocket.

I suggest you read my FAQ link a bit and rethinking your position on the answers you can recieve on Miataturbo.net.

Plus IIRC correctly you were asking suggestions on running a system at 215-245rwhp, in which case you really do want to consider engine management.
 

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you need 1.8 injectors, a msd box (or bipes if you know how to adjust or have someone who can help you)... i think you already have a starion intercooler as stated in your sig...

you can't do the 8-9lbs safely without bigger injectors though for sure.

in our car, we are running the vortech 8:1 disc.

TeRRy
 

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bipes is great.. get the 6:1 ratio disk for the vortech fpr 1.8 injectors and a 190 fuel pump ..install at the same time and you can do 8 psi safely with an intercooler.Correct me if i'm wrong guys but thats what i've learned over the past but
 

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Discussion Starter #13
braineak thanks for all that advice... i dont know how you can still put up with me because im still very new to the turbo scene. You mentioned that i should be running lean right now however at WOT my cars narrowband shows RICH. So just to recap if i want 240-250whp would 1.8 injectors be ok along with the MSD box/bipes and also a walbro 190 fuel pump? Anyone know how hard it is to install a fuel pump ?
 

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no 1.8L injectors wont be good for more than 190rwhp. pushing it with 330cc injectors. then you get into the range of not being able to idle them without aftermartker computers. which is exactly why people have suggested things like Emanage.

9-10psi with the correct fuel pressure will put you in the 180-200rwhp range.

I can show you my WBo2 logs of why they are at the limits.

It's hard to really gauge how the A/F mixture really looks on a NB:



which is exactly why it most likely sweeps back and forth at idle.

unless you have a fuel pump now, i assumed you didnt. then you'd be really overwhelmed with fuel, but still probably not overly rich.

but to sum up, no, it's going to be hard to support 240-250rwhp with injectors/FP/timing. Is it possible, technically it could be. I'm most likely in the 210-220rwhp range at 12psi. but I don't ever plan on rasing the boost without an aftermarket fueling device (I'm going with MegaSquirt)
 
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