Another S/C'd member worried about his AFR

[RagnaCaT]

Originally Posted by LtNoogie

I can't wait to see what a properly tuned Blitz'd Yaris can put out. I know we've been admonished not to put larger injectors on this car but hear me out on this theory.

What if the current fuel system with the Blitz piggyback fuel controller cannot pump enough fuel into the cylinders during WOT, leading to a lean condition. The ECU detects pre-ignition and has to retard timing to protect the engine, and as a consequence robs us of the maximum power the S/C can put out.

If I put slightly, not hugely, larger injectors in the car, it may run less lean during WOT and the ignition retard is less, giving more power. During idle or light throttle, the ECU detects a rich condition from the O2 sensor and is able to dial back the fuel to maintain proper AFR. Remember, I said slightly larger injectors, not fire hoses. If the increase in fuel is within the ECU's cabability to control, that could just work.

Anyhow, that's the theory I want to present to my dyno guy if I have him tune the car.

This is the smartest post, try OEM injectors from a 1.8 like corolla or XD could help you out??? i would go for it I swapped camry 2.0 3S-FE injectors on a corolla 1.6 4A-FE modded and got almost 2 hp at WOT and that was an N/A setup you are FI

[whooppee777]

at a local auto-x event this weekend i had a nice chat with a turbo charged xa and he told me that he was running the blitz supercharger with nitrous before going turbo (he's blown his engine 5 times)

he said he had a lot of issues with the belt slipping and asked him about a/f ratios and he said that the blitz kit really has the stock injectors pushed to its limits.

now this guy also works at the shop in northern virginia which has a high reutation so this isnt some averge joe, hes a tech at this shop that knows what hes talking about.

sounds like bigger injectors r the way to go and a stronger fuel pump would also help. an adjustable fuel pump is not an option on our cars. see cali's thread on his turbo build for the explanation

[whooppee777]

Originally Posted by CASTREX

Theoretically you could tune the car with the Camcom... however, I haven't seen any camcom sucsesfully installed in a Yaris.... yet.

the tein yaris had one successfully tuned with the camcom, it got like an additional 10 wheel hp/10 pounds of torque its in an issue of siphon. i cant remember who tuned it though

[LtNoogie]

Not adustable fuel pump. Adjustable fuel pressure regulator. Dyno guy is guessing that the fuel pump may be putting out sufficient max pressure but it could be regulated down too low for when we're boosting. A boost-sensitive fuel pressure regulator would tap into the vacuum line at the intake manifold and increase pressure when it senses boost pressures.

I'm starting my Internet research now.

[whooppee777]

Originally Posted by Yaris T-Sport

yeah, but the Tein yaris has the Greddy SC instead

yea i know but before the supercharger it was using the camcom, thats the important thing people either dont know or seem to forget

[CTScott]

I've been following this thread and doing some research. I think the CAMCON-T has a lot of potential with this issue (and it is fully compatible with the Yaris 1NZFE):

http://www.powerenterpriseusa.net/pr...con/camcon.htm

TOYOTA VVT-i & VVTL-i
The CAMCON-T controls the VVT-I timing +/- 20 degree in 15 different points of 500rpm increments within 2000rpm to 9000rpm Range.

A/F is controlled -10% to +20% in 17 different points of 500 rpm increments within the range of 1000rpm to 9000rpm.

[LtNoogie]

Anyone ready to be the first to try this?

http://forums.trinituner.com/forums/...ors-199355.htm

[Nexus1155]

if you're already taxing out the injectors why add more pressure to them! its like adding to the problem lol, especially if the fuel pump is not adequate enough as well

[LtNoogie]

Problem is there's no proof as to why the engine is starved for fuel. Not long enough duty cycle? There's no way to know if we're running at 80% duty cycle is there? Not enough fuel pressure? Not sure how to measure that under load.

Some of this is trial and error and hopefully the sharing of experiences on the SAME platform. It's nice to know what worked on a totally different car but...

[jkuchta]

Adding a little more pressure to the injectors shouldn't be a problem, and would be a good way to add a little more fuel.

The problem is the pump itself and the type of fuel system we have.

The fuel system is a returnless system...which means that fuel pressure changes are brought about by speeding up or slowing down the pump. To add a boost-referanced regulator you'd need to not only boost the pump pressure up over what the max fuel pressure would be, but you would also need to add a fuel return line back to the tank.

This is not impossible, but is a little work.

What someone ought to do is referance the pump voltage to the boost pressure. If it's not too taxing on the pump, that solution might circumvent the need for a return line. I have no idea what the ECU would have to say about that though.

[PETERPOOP]

The thought of slightly larger injectors seems to be worth trying. I just got my 1zz throttle body in the mail that I ordered weeks ago. I'll wait to put that on later.

[LtNoogie]

Originally Posted by jkuchta

Adding a little more pressure to the injectors shouldn't be a problem, and would be a good way to add a little more fuel.

The problem is the pump itself and the type of fuel system we have.

The fuel system is a returnless system...which means that fuel pressure changes are brought about by speeding up or slowing down the pump. To add a boost-referanced regulator you'd need to not only boost the pump pressure up over what the max fuel pressure would be, but you would also need to add a fuel return line back to the tank.

This is not impossible, but is a little work.

What someone ought to do is referance the pump voltage to the boost pressure. If it's not too taxing on the pump, that solution might circumvent the need for a return line. I have no idea what the ECU would have to say about that though.

I need to search the service manual to see if it gives the output fuel pressure of the OEM pump.

Originally Posted by PETERPOOP

The thought of slightly larger injectors seems to be worth trying. I just got my 1zz throttle body in the mail that I ordered weeks ago. I'll wait to put that on later.

Like I said, someone should try one method and I'll try another. But Peter, you've got to get some instrumentation so that you can see a before and after reading. No more butt dyno. We now know yours measures too high.

[Nexus1155]

i think the cars would be better off doing the garm conversion with the fuel system. But there would be an easy way to rig up some electricals to fool the system within a certain range. Worth a shot!!!!

[PETERPOOP]

Originally Posted by LtNoogie

I need to search the service manual to see if it gives the output fuel pressure of the OEM pump.



Like I said, someone should try one method and I'll try another. But Peter, you've got to get some instrumentation so that you can see a before and after reading. No more butt dyno. We now know yours measures too high.

My butt is too sensative I guess. I will have the scangauge II soon. I am willing to try the larger injectors. What about a combination of slightly larger injectors and the 1zz tb?

[LtNoogie]

If you more than one thing at a time, you'll never know which item contributed to the gain or loss in power.

I honestly do not know whether it was my intake, header, exhaust, or pulleys that changed the way the car ran. I did them all at nearly the same time. Maybe one of the mods was useless. I don't know.

[PETERPOOP]

Well I need to look for some 1zz fuel injectors now. I'll try those on, get some numbers, and then later, put the 1zz tb on that I have. Maybe they will equal eachother out?

[dallas]

You guys are doing some really great work at trying to figure out the lean condition. I'm sure there has to be 30 hp with a proper tune.
You would think the fuel pump can handle the volume of fuel needed to run 120hp, I think the problem must be somewhere else. it must be in the management, injectors, etc. I find it hard to believe that the car cannot compensate for a 20 hp increase. Has Blitz responded with anything?

[Nexus1155]

unlikely, but it wont be effective without tuning. You add more air youre going to need more fueling regardless. Might as well toss them both on, youd probably be in a situation a S load better than you are now!!!! Just to test it at least, make sure to have a wideband with you