Alright, I know that rotary engines last about 80k-100k depending on care. However most of the RX7s I've seen for sale have new turbos as well as engines. Do the turbos tend to go bad around 80k as well? Do they have to be replaced or are there kits to rebuild them?

Thanks,
-Charlie

 

Rebuilds are like $800 or so, you might want to find a good deal on the for sale section of the forum.

 

Turbo life depends on many factors. Regular maintenance and BOOST LEVEL you are running are probably the top two factors.

"I live my life one set of stock twins at a time, for those 3000 miles or less, I'm free"

 

if the turbos can sometimes last over 100k miles, and sometimes they are bad only 60k miles. Usually if the turbo does not get to enter the "parellel operation" condition frequent enough, the turbos will get more damage. Sometime the heat will pack around the pre-control doors and causing it to crack around the turbine housing and in between.
When the turbo is used to spin at a much higher rpm than stock setting (10.5psi) the bearing housing gets too hot and the seals gets worn out fast. The shafts gets out of balance etc....
When you get your turbos rebuilt, usually they just change out the brearings and oil seals, thrust plates etc. and balance the assembly... It is hard to find replacement turbine housings for the FD turbos. So if it is cracked a lot (like over 5mm), it probably cannot be fixed.

 

Mazda suggests to have a rebuild every 60k miles "I think"! I seem to have heard this somewhere before but this is only under normal driving conditions. The harder you push them the shorter they will last. Mine have 80k and are blowing a little oil but nothing serious. Upgrade to single in the near future

 

My stock twins have 120k+ miles no them and have run at 12.5lbs all their life, with occasional 15lb runs. The car has been autocrossed and seen track days all its life too. They don't have a drip of oil on them, boost fine, and don't smoke at all! I attribute that to careful warming and cooling of them before/after each run.

 

Tailhappy,

I'm sure it has something to do with the original owner changing the oil evey 3,000 miles for the first 89,000 miles of it's life.

Later, Steve

 

Please share what you do.

 

Hey, welcome back Steve! Yup, and I've carried on the tradition of religious 3000 mile changes! You're not going to start another Supra war are you????

Seriously, I'm just a firm believer of driving as easy as possible until you get to normal temps, and not boosting hard right before turning it off. I have buddies that hop in their cars and immediately run it to redline and it makes me cringe....

 

I've seen some turbos go out at 60k while some go out at 120k. Depends on the driving conditions. I also heard that rebuilt turbos suck and generally do not last long which is unfortunate for you twin turbo owners since a new one from mazda is over $3000 now. Another option is to get the 99 spec turbos from mazda comp for like $2900 which is more efficient, more reliable, and flows better and lasts longer than the stockers.

 

The car I'm looking at had the turbos replaced by Mazda under warranty 35k miles ago and just had the inner seals replaced 4k ago. It also comes with a turbo timer... If I let them warn up, drive nice before I shut it off, and use the turbo timer that should help them last longer right?

Thanks,
-Charlie

 

It's all debatable, but warming up and cooling down CAN'T hurt anything!

Turbo timers are questionable, too, since our turbos feed coolant through them. According to the PFC, my car's coolest right when I pull into the garage, and the water temp will go up about 10 deg C or more if I let it sit there and idle since there's no air flow. Plus it's not always a good idea to leave your car running and unattended.....just ask Steve

The other thing I've read is that if you want your turbos to last stay away from boosting much over 12psi regularly. They'll certainly handle 15 or so but keep it up long enough and they'll be blowing oil.

 

I have 143,000 on my original twins and have perfect boost. My engine was replaced at 120K.

David

 

I have never started a Supra war. I have only join in to clarify a couple of misconceptions. Besides since I bought a 3rd gen RX7 new and drove it for 8 years and 92,000 miles, Have pulled the engine on several TT RX7'
s, and built a T78 RX7, I feel I have quite a lot to add to this forum. Even if I do own a Surpa now.

Later, Steve

 

I'm with tail happy. It's all in the way you care for your car. Let it warm up properly and cool down properly. If you don't hit boost within the last 2 minutes of your ride, then you can just turn your car off when you stop. I try not to even use the turbo timer but I have one just in case I can't sit in it!!!

 

Hey tall happy, Justr a question for you. Would you say that 5 minutes is a good rule of thumb to get that kind of turbo life? I mean idling at least 5 minutes after starting and 5 minutes before shutting off?

 

my car takes about 15 min to warm up.
185f before shut off.

 

It is essential that the engine oil reaches "working temperature" before you race... In other words, if you wait at least 15 min before racing the turbos are able to survive at least 160.000 km even if you use the car hard!

The other most important thing to remember if you want to keep your turbos healthy is to wait at least 3 min before you turn of the engine after hard driving, if you don't, the oil will burn inside the turbo and eventually there will be no more sirculation of oil running through the turbo....