Capabilities of na motor
 

Hello all,
I recently purchased a 1994 toyota supra from north carolina and it is a 5 speed manual naturally aspirated engine and I was wanting to know how much horsepower can the na motor handle before needing to do engine work.
Thanks a lot for your inputs!

Well the 2jz is a very strong motor the twin turbo motor can go up to over 1000hp on stock parts. but the valve train can handle like 500-600 I think. so I believe the na motor is build the same just higher compression. also it would depend on how good the motor was taking care of.

You're wrong about the 2jz-gte valvetrain. It's also just fine to 1000hp. You do need to swap out the cams to achieve 1000hp though. The valvetrain itself is more of an rpm limitation than it is a horsepower limitation.

You're also wrong about the na motor. It's not built the same. The 2jz-gte has oil squirters that cool the pistons, and the 2jz-ge does not.

With the oem headgasket, you can probably squeeze 450rwhp out of it before needing to do some work. A much thicker headgasket might allow you to get to (my guess) about 550rwhp or so. Like Sonyps307 said, the higher compression pistons are the primary issue with going much beyond that point.

Well I seen that on another forum about the valvetrain. yeah I forgot about the oil squirters same as the 7m's but the parts still can take the 1000hp in the 2jz-GE right.

Only the crankshaft and the block can for certain. In the 2jz-ge, the connecting rods, pistons and the entire head are all different. I would not assume or tell anyone else that those parts are good to 1000hp if I wasn't sure...and I'm definitely not sure at all. In fact, I really doubt it.

To me, the entire n/a Supra is a just a poor de-tuned shadow copy of a TT. I've been very consistent with this advice: If you want the performance of a TT, then sell your n/a and get a TT. You'll save a lot of money. Nearly everything in an n/a except the body itself is a de-tuned, much weaker version of what you'd get in the TT. In other words, it's not just the 2jz-ge pistons, connecting rods, and head that sucks...it's the entire braking system and the rest of the driveline (transmission and differential), ecu, ignition system, suspension, etc., etc.. *shrug* The n/a is a paper tiger...it's just for show. If you want to tell folks you have a Supra and impress girls that know nothing about cars, your n/a will do the job just fine. If you want to go fast and stop fast, safely, sell your n/a and get a TT. Just mho.

Thanks for your inputs what I am probley going to end up doing is buying a cheap GE motor and build it from the block up and then beef up the tranny and upgrade brakes and do a E85 conversion kit to achieve my goal of around 850-900rwhp

My advice: Price it all out. You'll find it's cheaper (and much more efficient) to start with a good TT than an old and busted n/a.

Ok thanks for the advice. If you don't mind me asking but why would starting with a TT be different then just staring with an NA since they both have the same block and internals?

Because starting with a na u maybe paid 10-15,000 on the car then to make it into a TT would cost more then a stock tt. The tt's have better brakes, shocks and fuel system and the motor is already build for the turbo. Now u can spend 6-10,000 just getting it to take 800hp. When with a tt u could be at 800hp with just bigger turbo, fuel system, cams