Hi guys,

Just wondering if that is normal or if it could be something wrong.

I notice it when it is cold, and I'm accelerating, it is rather slow, but then when I reach 3000-3500 rpm engine jumps, like it get's another 50hp (no turbo installed).

What could this be ?

I have K&N, Exhaust header, 2.5" exhaust (no cat), other than that it's just standard. Been driven 274.000 KM. 5.29 diffs, 38" tires.

 

every car should do this, the colder air is more dense

 

That's a lot of HP For cold air !!

But when the engine is warm, I don't notice this, is the engine warming the air that much ? Could it have anything to do with the wider exhaust and less backpressure too ?

 

mine does the exact same thing. its always at 3000 rpm in first and second gear. im not really worried about it though

 

3000 rpm is basically the "powerband" on the 3vze and 5vze motors... they make much more power once they hit 3000 (that is where the "pull")
Dunno about 22re's, never driven one.

 

yeah my 22re really "hits" about 3300. I dont really know if you would call it a hit, but thats where the powers at.

 

I think it's called "on the cam" or something.

 

maybe the cold start injector is sticking in the on position causing the engine to run super rich, bogging the engine down a bit and 3000 rpm is where you get enough air to balance the mixture out and maybe a power boost. Maybe if that were the case, you could rig a toggle switch up to the CSI and bump it around 3000 for that "nitrous" effect. The CSI should only engage when the key is in the start position and engine coolant temp is below 80 degrees C.

Another possibility is that the O2 sensor could be caked with carbon, again causing over enrichment (less substantial) while cold...the ecu runs a rich mixture until the coolant temp sensor tells it the engine is at 80 degrees C...wild guesses, but some things to check out.

 

I just noticed the size of the exuaust tubing you have. Most will say that a 22re shouldn't go above 2.25" or the loss of backpressure will kill your low end torque and possibly burn valves.

 

Yup that 2.5 tubing will do it. That will kill your torque, and give it a really useless powerband on a truck. The only thing you really have a 22re is the torque. I drove my truck once without the cat back. It seemed like it had no power below 3500 rpms, but after that it got going. It was really loud too!!

 

One of my trucks runs a cheap header welded to a 3" dia. glass pack and the other has the stock exhaust. Both have the 22RE and both perform about the same. I think the whole "lack of back pressure" thing is BS that just keeps getting spread around the web. The reason most people don't go above 2.25" exhaust is because it is very hard to increase intake flow enough to match anything larger than that.
As far as your cold engine problem, I don't have an answer as to what is causing it, but I can tell you that all the 22RE equipped Toy's I've owned do it also, and I wouldn't worry about it.

 

I doubt it has anything to do with the tubing.. Could then just be normal while it is cold... Since I don't feel this when it is warm.. then it is more powerful in the lower bands than when it is cold.

But lack of power in lower bands could be over rich fuel mix, since that situation causes less power in lower rpms.. But then again it's only behaving that way when the engine is cold.

The truck's exhaust is LOUD, and it's ok.. I have one big open muffler on it, I'm considering getting another one some day, to get the loudness a little bit down.. sounds like a drag racer on higher rpm's and has a deep tone in lower rpm's.

There is NO CAT since the law here allows vehicles made prior to 1995 to have no CAT

 

my 87 two wheel drive with stock 22re has no cat and 2.50 inch pipe and muffler and dumps out the side in front of rear tire. below 2500rpm it dont have as much power it really comes to life after 3000rpm.

 

I was on the highway today and was making a pass and when it got to 3400 rpms I flew by them, I even told my friend in the car I wasnt expecting it at all. I think thats the first time I have passed someone that fast with my 22re lol