lack of high end power

[solarinsocal]

Anyone notice how the high rpm power drops off after about 5800 rpm? Is it just my engine? What is that? Too much exhaust backpressure, intake restriction, or is it valvetrain?

94' 1MZ

[midnightmach]

dunno what you mean.

[BlackCamSe]

maby rev-limiter

[Luckynumber5]

You might be leaning out if your fuel system is starting to feel the age. But you do need to understand the engine does not continue to make power the higher you rev it, the 1mz has nice high end cams, but eventually its gonna run out of steam.

[solarinsocal]

That is true, however both my MR2 and Supra will pull all of the way to the red without falling off but the Camry will not. Could be the difference between GE and FE heads I guess. I wanted to know whether or not this was a problem with my engine, or characteristic to the 1MZ. If it is characteristic to the 1MZ, what is the restriction?

[Luckynumber5]

Im no 1mz guru but see if you can find out if you are loosing fuel pressure in the higher rpms, it will feel just like a big power dropoff with no other symptoms. And yeah the fe heads arent anything special on the top end

[solarinsocal]

The power doesn't drop off. It just feels like the engine is only spinning after that and not pulling. It's hard to explain I guess. It feels like it's giving up toward the top. It's not something I am used to in my other vehicles.

[scdtrd]

For what it is worth, I too "feel" like it drops off..... so I put in a replacement Walbro fuel pump. That made a BIG diff in the pull. I believe it was the fuel pump not being able to feed the engine at that rpm and load.
SCDTRD

[Eye8Pussies]

^ hmmm....you think so? I would think that the stock fuel pump would be more than adequate for a pretty much stock engine, even if it is at hgh revs


solarinsocal: what other mods do you have? do you have a free-flo exhaust? a cai? anything that can let the engine breathe and expel air easier?


I have good pull all the way up to redline with no problems on mine
bu I have a full brullen free-flow exhaust, a custom cai by elperformance, and a custom y-pipe from ultimateperformance

[scdtrd]

Could also be the octane rating... i use nothing but 93... I have put in 87.. and you can tell the timing is rolled back. Anyway, that was my feeling on the issue.
SCDTRD

[88 LE]

Originally Posted by solarinsocal

That is true, however both my MR2 and Supra will pull all of the way to the red without falling off but the Camry will not. Could be the difference between GE and FE heads I guess.

Theres the difference. G and F head.

F is designed for torque. Peak torque happens at a low rpm. On a 5S-FE its at 4,400 rpm, not sure about a 1MZ-FE.

Toyota motors with the G head design are kinda laggy below 4,000 rpm or so. It picks up after 4,000 and pulls to redline no prob. Just what I've noticed.

G is more of a high flow, performance design. Ports are way bigger, wider valve angle, and the cams are independent.

[BlueFusion6851]

I've leaned my fuel out a bit, and I don't notice that much of a dropoff at high rpm anymore.

[WestCoastff]

So SCDTRD your saying you put in a walbro fuel pump and you felt gains? Did you do injectors or a fuel rail? is it a 190? Solar i think its just that its a 1mz camry engine, no jz supra motor haha... As for the lack of top end i guess the only real thing to do about fixing it is go for the snail

[willchugs400]

I have noticed the same thing. If you can find the numbers for a stock engine, you will notice that the power band will start to even out around the 5800 rpm mark.

[DiscoPotato]

88le is right. I raced my gen2 camry 3sfe with a 3sge mr2. of course i lost but i got off the line quicker and kept the lead until i hit the higher 5k rpm. i know im lost and this is a gen 3 post but im just saying that the heads affect the difference on power delivery. (i actually race with my gen2, my friends laugh so hard when i pull up on some cars. i think it's fun)