Yaris T1 (1kr-fe) (998cc) aviation conversion

[karman]

Hi All,

Hope someone can help me on this.

I'm converting the above motor for aviation use and need about 15hp more out of the stock motor at 6000rpm (climb/takeoff). Cruise is at ~5400 rpm. The rest of the RPM range don't get used (except for idling of course which can be anything from 1000-2500rpm ).

So, I was wondering what will the easiest mods be.
Noise is not issue.
Fuel usage not issue.
low -> mid range power not issue.


I have to change the throttle body from the "drive by wire" system to standard cable and so I can fit larger bore if that will help.
(Also don't need TPS sensor as throttle will always be advanced/retarded slowly)

Regarding the VVT-I. My understanding it only assist in mid rpm boost, don't do much or high rpm, is this correct? Otherwise I can simple activate it fully at X rpm and make it VVT (without I) as the older motors was.

Any input appreciated.

L:

[tooter]

I could be mistaken as I'm not an aviator, but don't aviation engines turn a lot slower? Pegging an automotible engine at redline under full load for long periods of time like takeoffs and landings sounds like a deathwish.

[why?]

what part of the intake and exhaust are you still actually using? If much of it, the usual bolt on mods would probably be enough to get you where you want.

If not the blitz supercharger would help.

[karman]

Hi,

@tooter:
Automotive conversions are very common and the 1kr-fe motor has proven to be very reliable already in airplanes. You get 2 of the shelf versions already, one boosted to about 120hp as well.

We run reduction drives for the props (~2400 rpm prop speed), standard Rotax aviation motors run about 5500 at takeoff, so the rpm is a non issue, just need change reduction ratio. Takeoff is only for few minutes then we reduce to climbing pwer (about 90%) even Rotax are not allowed to run at 5500 for more than 5 mins.

@why?
I'm still converting the motor, so its stock standard. The first things I have to get done is new exhaust manifold and new throttle body.

Can you maybe recommend some bolt on's?



L:

[Viperoni]

Driving through northern florida, I spent ~ 3hours straight at ~4500rpm in the 1NZ-FE.
I don't doubt the 1kr-fe could have handle higher revs for extended periods.
As long as the oil doesn't run over temp, it'll be fine.

Can't comment much on VVTI position, but it's meant to change throughout the power band to help with EGR when cruising, and optimizing power output when under load.


As for the motor, a properly tuned header would be your starting point.
After that, cams & cylinder head work are the next steps.

[xnamerxx]

Originally Posted by karman

Hi All,

Hope someone can help me on this.

I'm converting the above motor for aviation use and need about 15hp more out of the stock motor at 6000rpm (climb/takeoff). Cruise is at ~5400 rpm. The rest of the RPM range don't get used (except for idling of course which can be anything from 1000-2500rpm ).

So, I was wondering what will the easiest mods be.
Noise is not issue.
Fuel usage not issue.
low -> mid range power not issue.


I have to change the throttle body from the "drive by wire" system to standard cable and so I can fit larger bore if that will help.
(Also don't need TPS sensor as throttle will always be advanced/retarded slowly)

Regarding the VVT-I. My understanding it only assist in mid rpm boost, don't do much or high rpm, is this correct? Otherwise I can simple activate it fully at X rpm and make it VVT (without I) as the older motors was.

Any input appreciated.

L:

Boosting power at 6k rpms will require one or all of the following. Intake/Cams/Exhaust Manifold. Trying to get what is in essence almost a 30% boost in power will be difficult to say the least. I'm assuming the manifold you're having made has the lengths and diameters calculated for the RPMS you're planning on running? If it in it shouldn't be a whole lot more difficult to a intake made to do the same, that should get you close to your power goal and running an ECU tune to maximize power output should get you some more but I'd still be really shocked if you managed to find 15hp/tq from all of that.

As for VVTI tuning, its only set for emissions use and not much else.

The original ECU won't be useable since you're going to a cable actuated throttle. The throttle pedal on drive-by wire cars isn't a throttle pedal, its actually a just requesting a torque output. So when you put the pedal at 37% the ECU sees that as you requesting X% of torque, sets the VVTI, throttle position, and spark advance to get requested amount of torque. By you switching to a cable actuated throttle the ECU won't know how to respond and it'll either go into a limp mode or it'll go into baseline mode both of which will result in less optimal power output.

[karman]

Thanks for all the replies.

Yes, will be running aftermarket ECU as well as monitors for Cylinder Head temp and Exhaust temp (per cylinder) to get max out without damaging things.

It will be about another year before we will be flying, but will try and remember to report back.

Cheers
L:

[jetblast]

First find your local EAA chapter. I would solidify the foundation of the motor. Forged con rods and pistons. Additional baffling in the oil system, and possibly even a dry sump system. E3 sparkplugs for electrode redundancy. I miss my annual Oshkosh trips.

[karman]

Hi JetBlast.

The engine been proven already in aircraft, granted, not to 1000hrs as yet, but at least we know they do at least 500. Even if we have to replace it every 500, it still hell lot cheaper than brand names.

Dry sump is not needed and electrode redundancy is not possible. But each cylinder has its own coil, so if 1 goes, at least you have ~50% power left to get you to the crash site.

Redundancy will be in form of dual crank sensors, dual ECU, dual fuel pumps, each running on own electric circuit and 1 is always off (manual failover) to reduce posibility that shorts/spikes will blow/disable both.

One day when i'm big i'll make trip to Oshkosh ;-)
L:

[jetblast]

Electrode redundancy, not coil/magneto. Besides they offer awesome performance. Take back-ups when you can get them.

[karman]

Jetblast,

sorry, was speed reading, read "and" electrode redundancy, not "for" .

L:

L:

[jetblast]

No worries. :) I would love to see a tricked out (translated to fully polished outside, and fully forged inside) 1NZFE stuffed into an Experimental project. Could be a definite wow factor once a cowling is opened.

[cali yaris]

Trying to get what is in essence almost a 30% boost in power will be difficult to say the least.

where did you get 30%?

need about 15hp more out of the stock motor at 6000rpm (climb/takeoff).

[xnamerxx]

68 PS (50 kW; 67 hp) @ 6000

15/67=22%

I exaggerated a bit but its a serious ask to get that much power from boltons on a modern motor.

[cali yaris]

its a serious ask to get that much power from boltons

He's going to be running management, not just bolt ons.
With that, intake work, header/exhaust work, TB, and if needed, head and cam work, I see it as not difficult at all to reach a +15 hp goal.

Yes, will be running aftermarket ECU

[xnamerxx]

Rotrex only got 17 hp from their supercharger kit. Not saying bolt ons won't do it just saying it might not be as attainable as it is on a 1NZ-FE

http://power-enterprise.co.jp/rotrex/rotrex_iq.html

[cali yaris]

There's an easy 25%

[Yoda]

I got 109whp with just:
AFE Intake
NST Crank Pulley
DC Header
TRD Axle back Exhaust

If he gets into the engine and starts tuning you can expect about ~20whp more I think.