Has anyone successfully raises the Rev limiter on the 96 ecu?
kucsakanics said:sorry if i keep starting new messages not sure how to reply to one i send already but thanks for replying anyways would like to sample my new setup but has a flat spot when useing the 2rz computer that was modded( thanks for the link by the way worked out awsome but i did have to change both crystals) has a slight cough when passing 3000 rpm 2rz did 12.7 @102 8psi has alot more potential i just think the stock piston would have been better for the boost it was at (lustima 8.8 je pistons and rods and only 8psi) just didnt up the boost on it thought ide try a 3 and see where it goes before a rod breaks plus no fueling modds to support the extra boost sa pockets not so deep any help would be greatly appreciated
I looked into this some time ago. I have a 5VZ-FE, but the process is the same. The crystals are the two cylindrical shaped parts on each side of the processor. This is my ECU below, and the part you are replacing below that. You increase the crystal value by how much you want to raise the revs. I have a 16mhz and 8mhz on my ECU, so you could increase it by 10% to a 17.6 and a 8.8 and it would raise the rev limit also by 10% to around 6050 RPM. The downside is that the ECU doesn't know it's spinning the engine faster so the fuel trims will be off by 10% as well as ignition timing is too far advanced.
I never dyno'd my engine with my aftermarket cams on it so I never knew if the engine flowed well enough to even warrant the increase. With stock cams on a 5VZ-FE it's not worth it (no power to be had up high, nothing beyond 4800 RPM). With a turbo'd 2RZ there might be, but a dyno will tell the full story and see if you're still actually making power that high.
And this is the part you are replacing:
I've read a lot about the DLC connector not working, but nothing really saying how much you can overclock without causing significant damage. I did read that someone installed a crystal with a frequency 35% faster than the stock one with no issues. Although this wasn't on a Tacoma ECU, but still a Denso unit. It seems this crystal mod is very popular with any vehicle that has a Denso ECU...I'd like to try the unit made by Magnum (i think) that you can change the values on with the turn of a dial(or maybe a push of a button), but it's a lil pricey. Somewhere around 200 bucks ?The stock ECU doesn't like to be skewd too much because it starts to affect other systems. For my '98 2RZ, somewhere between 8% and 10% works well (6200-6300RPM). Also, with a modded ECU, it will not communicate with scanners thru your DLC connector because the scanner will be operating at different a speed
I'm basing most of my knowledge of what others have done and posted on the 100% reliable internet, even better that it's from 100% reliable forums!Is there a limit to how much you can change the crystals by? I ask because ideally, I'd like to increase the rev limit on my 2rz to 7k, which would be about 25% more than stock. How certain are you that timing is advanced and not retarded? has this been confirmed? if so I can easily pull the timing, but just want to be sure. The same goes for the fuel trimming. Is it pulling or adding fuel when you overclock the ECU?
With the turbo I have, I'm hitting peak boost (17 psi) at 5k RPM and the engine starts to make really good power and is still climbing when the stock rev limiter hits.
That video that I linked in my last reply shows a guy installing that magnum unit in a denso ECU with 2 crystals I think. Only one unit required it looks like. But I'm not 100%. It's looking more and more like I just need to go standalone, but its the price that kills me honestly.I'm basing most of my knowledge of what others have done and posted on the 100% reliable internet, even better that it's from 100% reliable forums!
I can't saw with complete confidence it'll advance the timing. The blip at 3K RPM's would make sense though since that's when the signal from the knock sensors start, so it does seem to affect it. I also saw the Magnum product but since mine has two crystals, I'd need two units adjusted side by side. $400 isn't worth it for me so if I ever do this, I'll buy a spare used ECU, mod it something safe like 8-10% and swap ECU's. If you haven't already, it's not much work to pull your ECU, open the case and snap a few photos to see what you'll need to get it done.
I'm guessing you already know what you need to do to the motor for it to handle 7K RPM's.