IRP 140 Amp Alternator

IRP 140 Amp Alternator

Currently Backordered


The stock FD alternator is rated at 90 amps, which is adequate for stock cars. IRP's 140 amp upgrade significantly improves the charging system’s capacity. They can upgrade both FD and FC alternators. If you are running aftermarket gauges, stereo, larger fuel pumps, auxiliary lighting, mini battery, etc this is a very worthwhile upgrade. Each alternator starts with a full cleaning and media blasting of the case. The alternator then undergoes a full rebuild. A larger stator with more windings and matching regulator is fitted to increase the amperage. Don’t be fooled by others claiming a higher output. Those units have to be spun much faster to generate the claimed amperage and will cause charging issues at idle. We have tried and tested these units and have found the best balance of output vs rpm.

While IRP can update S4 and S5 FC Alternators there are some limitations due to the size of the casing. S4 alternators can typically hit around 100amps ~ S5 they can get closer to the 135/140 mark. If you have a S4 RX7 and need more then 100amps we would recommend upgrading to retrofit an S5 or FD alternator.

-Please note that we require your core alternator to perform the rebuild and upgrade. Due to the increased cost of alternator cores, we had to increase the core fee. There is an $125 core fee if you are not supplying us with your alternator first, which is refundable upon receiving a good core.

– An alternator with a cracked case is not acceptable as a core. The most common way this happens is trying to hold the alternator stationary by inserting a screwdriver or other tool through the vanes of the case while removing the pulley nut. The pulley nut must be removed with an impact wrench.

-There will be a $30 fee charged to replace a broken alternator post. The most common way this breaks is improper padding during shipping. We recommend that you remove the post and send it with the alternator but package it with packing material to avoid damage.

Please note: Powder Coating may add 1-2 weeks depending on color choice.

Please contact us for more details.