My 1JZ Dyno Results before going standalone...

[Spaniard]

Hey guys, went to the dyno not too long ago and put down some numbers before I go big standalone and BC 272 cams with cam gears.

1JZ-GTE
GT-35 (yes, non-ball bearing)
S-AFC II (pulling a lot of timing!)
with Supporting mods....

Conditions:

Temp: 94 deg.
Humidity: 34% but national weather service said a lot more. idk.

Running 15psi exactly, putting down 327 when I came in, then make another pass with a couple changes to the S-AFC I put down a solid 350rwhp. I saw not bad considering the high temperature in the middle of the day and with a fuel controller pulling lots of timing.

Sorry the picture got cut off, but the printer was acting up all day. Also, the AFR was being read by a sniffer and not an actual wideband at the downpipe. So the AFR's are slightly off.

 

[Jostar]

You did the pulls on 3rd gear, You are supposed to do them in 4th gear to be more accurate.

 

[Spaniard]

You did the pulls on 3rd gear, You are supposed to do them in 4th gear to be more accurate.

I told the dyno guy that it should have been done in 4th, but he said 3rd is best. I was not about to argue with him, it was his dyno and I was on there for free. Though, I did get him to do one pull in fourth and it yielded 342 rwhp. So, is it really that different? It is a brand new dyno and been calibrated to spec only a week earlier by a dynojet tech. So the dyno is fine.

 

[tlo86]

i didnt even know that what gear for an auto?

 

[viperkillertt]

3rd is definately most common. I might try 4th next time, but i ran mine in 3rd last time.

 

[str8_6]

are you going to put the crowers and then dyno....after that put the standalone and then redyno? or all at once?

it would be nice to see how much you put down with just the cams.

 

[viperkillertt]

are you going to put the crowers and then dyno....after that put the standalone and then redyno? or all at once?

it would be nice to see how much you put down with just the cams.

I agree!

 

[Spaniard]

are you going to put the crowers and then dyno....after that put the standalone and then redyno? or all at once?

it would be nice to see how much you put down with just the cams.

As much as I would like to, I may not, because I am going to put 550's in there an dont want to risk the huge timing pull from the SAFC. I rather just do both at the same time. There may be a chance that I can do a before and after. We'll see.

 

[Jostar]

Standalone will make the biggest difference, I love my AEM!!!

 

[Syris]

More people need to understand this....4rth gear is direct drive on a 5spd and is 1:1 and will give true results which is where is should be dynoed, now on a 4spd automatic it should be dynoed in 3rd which is technically direct drive as in auto's 4rth is overdrive.

 

[Jostar]

More people need to understand this....4rth gear is direct drive on a 5spd and is 1:1 and will give true results which is where is should be dynoed, now on a 4spd automatic it should be dynoed in 3rd which is technically direct drive as in auto's 4rth is overdrive.

You are right, 4th gear is the 1:1 gear ation on the trans....

 

[dansmith11]

ive always wondered about this.. does being in a 1:1 gear really make that much difference?

i mean, yes, your trans is 1:1 in 4th (on most 5spds) but every car is gonna have different rear end gearing.. so doesnt that make it kind of irrelevant?

if gear ratios affects the reading that much, how can you ever compare 2 different cars power levels? since they will have different gearing, even both in 4th.

 

[tissimo]

Mkivs always dyno in 4th which isn't 1:1, their 5th gear is..

the reason for the 1:1 i think is to just give more load on the engine. It doesn't really matter too much if you dyno in 3rd or 4th. The numbers maybe a tad different but usually close.

 

[Syris]

5th gear is an overdrive gear but when it comes to a 6 spd both 5th and 6th are an overdrive gear, but like you said 5th is 1:1 which will give true results.

It actually does matter what gear you dyno as gear ratio's are how much the power will be multiplied. For example a car that has 1st gear as 3.00 and 4th gear as 1:1. The car dynoed 300whp in 4th gear, if you took that same car and then dynoed in only first gear you would come out with a number of 900whp.
1x300 = 300
3x300 = 900

Why is this? The power is directly through the input to the output and isnt being multiplied through the gears. The 1st gear is a shorter gear allowing you to accelerate but while in 4th gear being only 1:1 it is more for the higher speed and not the acceleration you needed to move the vehicle per say.

 

[Spaniard]

Then why did I dyno 342rwhp in 4th?

 

[tissimo]

could be any number of reasons, probably just heat soak though

 

[Syris]

ive always wondered about this.. does being in a 1:1 gear really make that much difference?

i mean, yes, your trans is 1:1 in 4th (on most 5spds) but every car is gonna have different rear end gearing.. so doesnt that make it kind of irrelevant?

if gear ratios affects the reading that much, how can you ever compare 2 different cars power levels? since they will have different gearing, even both in 4th.

The simplest way I can think of right now to explain a rear end is this...

The rear end comes into play as to how many times the tires rotate, not how much power is being put down. The rear end is to determine a top speed and/or in other instances when turning and how the wheels will react when going around corners as far as turning.

 

[Syris]

Then why did I dyno 342rwhp in 4th?

Because that is the output of the engine.....but like tissimo stated there is other things that will come into play to hinder your results in different scenarios.

 

[str8_6]

i agree with everything syris says, but from personel experience i did 368 in 3rd and 362 in 4th.

 

[viperkillertt]

i agree with everything syris says, but from personel experience i did 368 in 3rd and 362 in 4th.

Interesting, i might try it next week. I need to cut my cat and then i will see what the difference between cat and no cat is. Oh, if anyone is in the area and wants to dyno, my school is doing a benefit on Saturday, 40 bucks first pull and 10 dollars after that. Bellingham, WA The proceeds go to formula SAE.