Water methanol suggestion with failsafe
 

Hey All,


Going to finally get around to putting water meth on my rig since it's now my daily driver. It's a 98 with TRD SC 2.1 pulley and 7th injector. From what I've read, I should still keep my 7th injector to help with fuel on the top end and partial boost enrichment, thoughts? Was going to go with the same setup that Speedy had done, but finding out that's coming from UK and could be a bit before I could get my hands on it was wanting to see everyone's opinion on the Devil's Own setup and or others stateside.

Second, I have seen that AEM has a failsafe that some people have used, but haven't seen much on how it works. What do you guys recommend as a failsafe?


Thanks everyone!

Our engines are extremely resistant to knock so a failsafe isn't critical. For most other makes and engines, if they encountered as much spark knock as our engines do the engine would blow. These 5VZ-FE's are very stout and can handle a lot of abuse.

The fact that you have ignition retard where it's needed and extra fuel up high to keep temperatures cool with the 7th injector means you already have more engine protection from spark knock than most supercharged 5VZ-FE's. Unlike most modern cars, there's very little gain from water/meth since we cannot advance timing so those power gains that Devil's Own and Snow Performance aren't possible on our engines. There is however some power to be gained by leaning out beyond the 11.5 - 11.8 AFR's that the URD tune is based on. I leaned out my tune from about 11.2-11.5 AFR to about 12.0 - 12.2 and gained +20 RWTQ. You can't run that lean on gasoline alone and still be safe. Well, you'd have to be running like 94 or 95 octane.

Gotcha,


I mainly want to get rid of the timing retard. Has always made it feel like it's being held back, I think that's more noticeable being a 5spd. Even with timing pulled and the additional fuel I'll get spark knock, but it's not all the time.

At or above 3000 RPM's, the knock sensors' signal is read by the ECU and will protect against spark knock. Yes, that means the ECU completely ignores knock below 3000 RPM's. That's why our engines ping so much under boost in the low throttle/RPM situations.

If you pull timing above 3000 RPM, the ECU will add it back in. I experimented with this (Gadget from URD laid out the principles first though) and did a WOT run in 2nd gear and I saw a max of 17 degrees of timing advance. I then changed the ignition map to -2 to pull two degrees of timing and what do you know, my next run showed 19 degrees of max timing advance. Did I just gain two degrees of timing? No, it just added it back in since the ECU looks to run at max timing advance.

Do a WOT pull and record your max timing. Should be around 16-17 degrees (higher if you have timing retard) at it's highest point. If you see anything less, you can benefit from higher octane fuel like methanol.

As a rule of thumb, each degree of timing adds 1% of max HP. So that's about 2 HP, not very much. Even if you manage to gain say, 3 degrees of timing advance (which would be generous) that's only 6 HP. The deckplate mod will give you more HP than that and be way less work. Or switching to a high flow filter like from aFe Power. Or removing 120 lbs of tools and junk from your rear cargo area (free power!). Catch where I'm going with this? There's easier and cheaper ways to get more power from your engine.

For the rebuild I had my heads and block decked some and heard pinging at times. It doesn’t surprise me Toyota only cares about detonation above 3000rpm rather that actively looking at it all the time like my Saturn and their Active Knock Retard algorithm they have patented.

Having a bad coil will take a few miles of driving before you get a missfire code. So it figures.


Sent from my iPhone using Tapatalk

So the timing retard I've put in the computer counteracts? That would make sense of why it feels kind of herky-jerky unless I'm WOT. would you suggest taking the timing retard out?


Sounds like I need to research what the deck plate mode is....

You can, but take it out slowly. Best to do it on a hot day as the hot air will cause it to ping easier, mine never does in the winter but will a bit in the summer. Add back timing about 0.5 degrees at a time until you encounter ping (usually it's on climbs up a hill in the 2000-2500 RPM range) and then retard it back a degree or two for safety. Be sure to also run the highest octane fuel you can get, for CA that's 91 but many other states have 92 or 93.