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Cut Out At 5500 Rpm In 5Th And About 7000 In 4Th. No Speed Sensor ?

reeceo21

By reeceo21,
in General Maintenance

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reeceo21 Community Regular

reeceo21

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Posted

Hey everybody just completed my rb25 box conversion in my rb25ed 32 4 door. Now my problem is at 5500rpm in fifth it feels like i hit a wall. It will not go any where past 5500, And im pretty sure its only WOT that it does it. Someone suggested speed limiter. Sounds logical BUT i dont have the cable hooked up ? The reason it doesnt make sense is it will bounce the limiter in the third but 4th hits the wall at around 7000 and 5th hits at 5500. I dont think its fuel as it has a good bosh 040 pump and here it whizzing and all other gears are fine. Now this problem has only just happened after the box. Therefore thats why im thinking maybe some sort of limiter is in place because of it. Related mods that may help find the problem are as follows

-FMIC

-Plugs were changed about 1000k ago

-Nistuned r32 ecu

-Bosch 040

-Apexi pod in a box

-3' straight through exhaust

-34 turbo at around 10 psi

Someone suggested just give the yellow wire the snip (53) and try but would prefer to know if anyone has ever had any experiences like this.

mad082 Grand Master

mad082

Posted
Posted

it could just be the speed cut, but i'd have thought that 5500rpm in 5th is above 180kmh. i'd say that you are just not making enough power to overcome the drag. you'll need a lot more power to get to redline in 5th gear. when i still had access to the runway at the local airport my r33 topped out at about 6500rpm.

but if you are getting a lower rev limit in 4th as well, then it's speed cut. my old 180sx hit the speed cut on the dyno at 7000rpm (500rpm below the rev limit)

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