Scion XB 1NZ-FE Turbo build

[xnamerxx]

Im pretty sure the power is giving up so early because the turbo is to small for the amount of power hes making. You can see it in the torque curve how it starts to die at 5k rpm's. Dont know the specs on his cam or the rpm range of the intake he's running but Id have to hazard a guess and say both are rated for something like 3-7.3k rpms but the turbo doesn't have the cfm to keep up.

If you look at the compressor map for the disco potato it gives up on at about 35 lb per minute with 2.2 bar. Rule of thumb is 10 hp per every lb per minute so easy math says 350 hp give or take 20 hp.

[Nexus1155]

Tial / Garrett GTX-2860 RS Turbo w/ SS Housing and Billet Wheel
Walboro 255l , Aeromotive regulator , Perrin fuel rail ,
Aerospace Components custom fuel block for NX kit
680cc Precision injectors

for xnamerxx ^^^

Does your standalone tell you the duty cycle the injectors are running at. Looking at that graph seems like you have something more to work with, like a handful of the people here say.

[xnamerxx]

Its a walboro 255 so it should be good for the power the injectors are 60lb which are again probably good for the power hes making. We don't have the fuel rail pressure nor do we have duty cycle so those are 2 unknowns.

But seeing as the Yaris was never engineered to have 350+ hp id be willing to be the fuel lines from the tank to the engine are to small.
Garm what are you running for fuel lines? 8an?

Im not trying to bash xbgod on his build to each their own poison but running that dangerously lean and nitrous will result in a nitrous backfire which will blow your intake off the car.
If the fuel issues get fixed and you run nitrous please do not go over a 50 shot with this small of a motor or you'l get to meet mr puddles and blow your intake up and probably wreck your turbo. Trust me with this I have nitrous on another car and I've run a 150 shot there is nothing scarier than watching your fuel pressure drop from 39 psi to 24 psi for a microsecond and jump back up.

[Blown_xa]

Originally Posted by xbgod

Haven't considered E85. And to the other guy on my fuel pump, lines and so fourth, are you serious? I'm not even going to respond to that. All is working well and tune is great. I made good numbers and now I'm movin on. It's time to finish pimping it to look sexy and wash and wax it. The only thing I'm doing on the side is getting involved with someone else on a real cam set for these motors. This will be in the works for a little while but you can bet when I'm done with R/D with that it will be bullet proof. Don't ask me any questions on it cause it's top secret right now. But you can rest assured I will have a real head cam set for next year. It's been alot of fun and I set out to make power and did so. So if your a hater out there then beat my numbers, good luck.

XBG

Hey man, don't worry about the critical posts. Every forum is full of haters and people who just sound off to make themselves feel better into thinking they know what they are talking about ... even though they don't. Do your thing, ignore the crap. A formula 1 team could come on this forum presenting performance parts, people would still question them and complain. They would "check with their sources" to satisfy themselves with usless opinionated info.

[Nexus1155]

Hey man, don't worry about the critical posts.

Blown, I know you are knowledgeable, surely you must see the drop off in power and then a sudden lean condition. You see no problem with that?RPM still increased. he didn't let off the gas.

[xnamerxx]

No one here is hating on him they are all pointing out a giant problem with his afr.

Ever wonder why evos, sti, cobras, vettes, vw's, or any other car that has a forced induction engine runs at afrs around 12:1 or less its not because there trying to sap power from the motor its because running any leaner results in detonation/pre-ignition and combustion temperatures that are to high.




Hey what do you know on a STI the afr is less than 15:1 what a shocker and hey its running meth what do you know.

[cali yaris]

Every forum is full of haters and people who just sound off

^ Are you including me in that? I asked a legitimate tuning question, and congratulated him on his numbers. And the question remains unanswered.

[Parmas]

Originally Posted by xnamerxx

No one here is hating on him they are all pointing out a giant problem with his afr.

Ever wonder why evos, sti, cobras, vettes, vw's, or any other car that has a forced induction engine runs at afrs around 12:1 or less its not because there trying to sap power from the motor its because running any leaner results in detonation/pre-ignition and combustion temperatures that are to high.




Hey what do you know on a STI the afr is less than 15:1 what a shocker and hey its running meth what do you know.

I don't know but that dyno is sweet still on the AFR which btw that is a proper tune for me..... Stoich off boost and low 12 on boost. I am really curious I can be able to make a tune map like this myself!

[cdydjded]

Originally Posted by cali yaris

1. Why it was so lean.
2. Why the power curve gives up early.

IMO

1 Cant intelligently answer that from this side of a keyboard. Need more info....
2 Ported head with stock cams

[cali yaris]

^ I have a ported head with stock cams, so I don't think that's it.

[Blown_xa]

Originally Posted by cali yaris

^ Are you including me in that? I asked a legitimate tuning question, and congratulated him on his numbers. And the question remains unanswered.

Garm, like said already ...you are looking at the torque curve. The power hardly drops off. As far as afr's, im not gonna speculate. We have run 13.0 on our race car for good numbers on the dyno, it liked running lean. But after the insane power pulls were done we immediately corrected the afr's for racing trim. It may very well be the same in his case. Only his tuner can answer that question about the afr's on that particular pull, but what everyone failed to notice, is the pull ended early around 6000rpm . So my guess is the tuner let off knowing. The car may have made the best power on that pull so that is why it was posted. Only other reason for pull showing an end at 6000rpm would be because rpm's were based off roadspeed and the graph got trunkcated do to tire expansion.

[cali yaris]

1. You didn't answer if you were including me in the word "haters" that you used.

2. Yes, I was looking at the torque curve. Regardless of which curve you'd like to discuss, the motor peaks very early; I asked why. I disagree with you that "The power hardly drops off." It's done at 5200. It drops off enough that the tuner stopped the pull early, as you noticed.

3. You can "not speculate" on the AFR's all you want -- but the dyno got posted and we get to discuss it, right? That looks too lean to me. (I could always be wrong, but I don't think I am on that detail).

Only his tuner can answer that question about the afr's on that particular pull,

Right. And if it were my car, I'd be asking that question before I drove away with it tuned like that.

[cdydjded]

Originally Posted by cali yaris

^ I have a ported head with stock cams, so I don't think that's it.

Yes you do & it was ported by someone else. A ported head by one guy is not he same as a ported head by another. Completly uncomparable.

[cali yaris]

OK, I can't argue because I don't know enough, I'll admit that. Maybe the porting job alone gave him a power curve where horsepower is done by 5200. Were there some pics posted of the head? I can't remember.

[cdydjded]

Pics alone cannot give you any information. A flow chart is needed.

[xnamerxx]

Since you seem to understand this subject so much explain why a stock yaris is able to keep making power past 5200 rpm's and this dudes motor is out of steam at 5200 rpm's.

All I want is a explanation as to why that would be the case.

[cdydjded]

Originally Posted by xnamerxx

Since you seem to understand this subject so much explain why a stock yaris is able to keep making power past 5200 rpm's and this dudes motor is out of steam at 5200 rpm's.

All I want is a explanation as to why that would be the case.

Is you question towards me?

[xnamerxx]

Yes, I want a explanation as to why a very modded car is plateauing in power at 5200 rpms where as a stock yaris would not be doing that if it really was a problem with heads and cams.