Will a Piggyback raise the rev limit?

Merxus Benz

New Member
I have read somewhere that piggyback ecus dont do much on the 1uz-fe. I am using the front cut from a 90 celsior and would like to raise the rev limiter and defeat the speed restriction. Is this possible? Has anyone had any experience with them? I would assume that being a 90 model it was before the advanced emissions programming in the ecu that makes modern cars hard to impossible to put on a dyno.


New Member
By raising the redline you will not gain any power. The 1uz has power up to 6000 rpm, where the cam's profile falls off immidiatly. If your piggyback can tune your AFR/timing at all there are gains to be found there. I have seen decent gains from a well engineered exhaust/headers with a well thoughtout tune. 230rwhp I suppose could be done on a light budget.

Merxus Benz

New Member
The specs list the rev limit as 5600 so lifting it to 6000 would be helpfull. Budget is not a problem and the car is getting a full exhaust. I would prefer to keep the original ecu for a variety of reasons. Being a jap import the speed restrictor has to be removed (limited to 180km/h no good for track work) and i was hoping someone on here had experience with a piggyback and could share it.


Super Moderator
Staff member
I think if you check on the ALSC Site they have someone who can remove the speed limiter.

All UZ's ECU's allow them to rev to 7,200rpm.

I don't think you need a piggyback to change the red line as 7,200 is way past the useable powerband of the engine anyway.

Headers will give you a little (not as much as we would all like!) and without cam changes that then move into porting to get the benefit of the cost which then forces you down an aftermarket ECU there isn't much point to it all.