raising the rev limiter

[Faultline]

I was reading a thread On "spyder chat" where they tuned their 1zz spyder to rev up to 7400 rpms. They are using the "power FC", which is a stand alone engine management computer...For a "stand alone" it is reasonalbe $$ costing around 1k...But I dont want the pfc...I just want to rev to over 7k.MWR seems to think that 7400 is safe..what sensor does our ECU read , then cuts the motor at 6400rpms???Do suppose their is anyway to tweak the voltage from that sensor , so that when the ecu is reading 6400rpms, my 1zz is reving 7200rpms??? he he he he!..or any other ways I could fool the ecu??

[pa-vibe]

Replacing the ecu or adding a plug in type device is the best way to go. Actually it may be the only way to go. If you try to scale the sensor input it could really mess up timing(ignition, injector, vvt). I believe even if you could just give it a max span, meaning that the ecu never thinks it goes over the set RPM limit, the timing would be screwed up enough that it probably would not function in a desireable way if at all. The unichip may be the best option. just my 2 cents

[Faultline]

yeah....You are probably right..I was thinking the crank sensor...and I know that would be timing too....wouldnt the vvt be with the cam sensor though?....when you say "plug in device", what would that mean?..It would have to do some thing to inter=change with the ecu, I mean, the sc kit is a piggyback system, and it raises the the limiter to 6800...how does it do it?...this is obviously out of my league.

[satur9]

im pretty sure mike stafford could figure something.your turbo fuel system is boost dependent.but if you rev higher youll need something to keep those injectors spraying.i dont know if tricking the sensor for rev limiter will also trick the stock ecu into giving you more fuel at those rpm. but as stated above the unichip should.almost anything aftermarket where you need a rpm signal usualy gets it from the ignition system like off f a coil

[futseal04]

Just another point of view.....Have you had your vibe dynoed? If you have, you should look at the HP graph and see if it would really be worth it to rev that high. Secondly, i don't know if they make one yet, but Hypertech's power programmers allow you to to go in and compensate for different sized wheels, alter shift points, fan control, etc. I will do some research on that and get back to you....

[futseal04]

News flash.......Hypertech only does GM trucks and 3800 V6's.......

[pa-vibe]

A plug in device would be like the device GM provides with the sc. This plugs into the ecu as a piggyback unit. I believe that raising the rev limiter a few thousand rpms would be worth it since the vvti allows for max HP at around 6800. I am still getting aquinted with the toyota VVTi operation, but my take is that this engine will have both a crank sensor for piston position and either one or two cam sensors for feedabck to the ecu hence the "i" in VVTi. But I am not sure of this. I think the best way to do this is the unichip. I will research some more because I am interasted as well.

[Faultline]

Quote, originally posted by pa-vibe »A plug in device would be like the device GM provides with the sc. This plugs into the ecu as a piggyback unit. I believe that raising the rev limiter a few thousand rpms would be worth it since the vvti allows for max HP at around 6800. I am still getting aquinted with the toyota VVTi operation, but my take is that this engine will have both a crank sensor for piston position and either one or two cam sensors for feedabck to the ecu hence the "i" in VVTi. But I am not sure of this. I think the best way to do this is the unichip. I will research some more because I am interasted as well.(I have been away), but, originally I had been talking to Split-second about fuel and timing controlls, and questioned them if the ftc-1 unit would work on a Vibe like it does for the celica. they said it should , as long as the cam,crank, and air sensors were the same.I never pusued this, and right now now with my turbo, I only control the fuel.As it is now, I feel the turbo pulling harder and harder till red line. I believe that the motor response well to all the extra air at the high end. Some one asked about dynoes,...the dynoes I have seen for the celica, show the hp rise continually to 7k whil underboost, and even if it flattens out, it would be nice to shift to 5k , which has more power than 4k..it would be like having a 6spd....sorta.