Cap's MAF mod with fuel pressure

[Optimus prime]

Hi Guys,

I've done a lot of reading into Caps MAF mod as found here: https://www.spyderchat.com/forums/showthread.php?34825-1-and-2-ZZ-ECU-s-Side-by-Side-Sorta

This mod is not secret and is done but many people with great results by removing the intake vanes and replacing the injectors to yellow 310cc. Within Caps post he indicates that increasing the fuel pressure will increase the fuel delivery much the same as the bigger injectors. This is essential so that in closed loop the ECU get's an adequate AFR reading.

Further reading in to Cap's post his LTFR sit at -7 which tells me the 310cc injectors are over fuelling and it's being corrected in the stock ECU.

As I will soon have other bolt on mods added to my car, my parameters will be different to Caps. I'm looking for a more 'tune-able' solution and I would also like to get my LTFR closer to stock (0). I figured I could achieve this with an adjustable Fuel Pressure Regulator BUT after further research I find that MR2's do not have a fuel return system BUT I understand you can buy non-return FPR's which effectively decrease pressure(?).
SO if I crushed the standard FPR to 60 PSI (max) I would then have the ability to tune for an ideal AFR?   

Am I barking up the wrong tree? I think I have the theory nailed but not too sure on the practicalities.

I would love your input on this.

[lamcote]

That all makes perfect sense to me other than the reference to the non return FPR reducing pressure. I haven't seen one of these, can you elaborate further? I can't work out how you could reduce the pressure without some form of return line.

Are you sure you need less than 60psi?

[Optimus prime]

To be honest that's what i'm still researching into... I would love to have control over the FPR. It also doesn't seem like I'm able control the pump speed by varying the voltage either
If only the MR2 had a fuel return system!

I'm very tempted to buy a Greddy Blue and have a crack at it... but that's another learning curve for another day.

[lamcote]

No I think that's right. Basically the standard system has a FPR inside the tank so the pressure coming out of it is fixed by that.

It's not a massive job to convert the system into a return system if you really want one, quite a few people have done it. BUT it is easier to just fit 310cc injectors if you're just after the MAF mod.

Or crush the FPR in little steps until you get the pressure you want.

[shnazzle]

Few things:

1) maf mod plays with the MAF readings of the car to make it think one thing, and giving it bigger injectors (that it does t know about) to bring things back into balance.
The more tuneable alternative you're looking for is called a standalone ecu or a good piggyback
Then you can change the MAF signal and up fueling to achieve the same.

2) LTFT of 0 isn't perse the goal. The stock ECU adjusts fueling also bevause of aging sensors and other components. Forcing it to 0 might actually be making it less efficient.

[Optimus prime]

I suppose the goal of the MAF mod was to increase performance with little expence. It gets you a good way there, although not 'perfect' ...but it's not a problem! I fully understand what you're saying about the fuel trims but my OCD is metaphorically attacking me for accepting your reasoning.

I suppose you're right about the ECU upgrade... oh well, here goes the next few weeks reading up about the greddy units 🙂

[m1tch]

I suppose the goal of the MAF mod was to increase performance with little expence. It gets you a good way there, although not 'perfect' ...but it's not a problem! I fully understand what you're saying about the fuel trims but my OCD is metaphorically attacking me for accepting your reasoning.

I suppose you're right about the ECU upgrade... oh well, here goes the next few weeks reading up about the greddy units 🙂

If you are after a bit of extra performance, don't try and fool the stock ECU, look to reduce the overall weight of the car, its fairly easy to drop a bit of weight from the car - its all about power to weight. Remember that my car is currently on 176k miles.

Here are the results for a few tests whilst drag racing (using it as a yard stick as it relates to acceleration), I have now moved onto a Link Xtreme ECU so my PFC will be up for grabs including maps etc.

Here is my initial baseline run - only mods for this was the decat manifold and drop in filter, was running 100% stock weight, stock tyre pressures:

2.2833 second 60 foot
15.8627 second 1/4 mile
86.86mph terminal

Best run on the stock ECU with around 60kg weight saving (will work out the exact amount later) although was still running 2/3 of a tank, stock tyre pressures:

2.1302 second 60 foot (best 60 foot was a 2.0917)
15.1987 second 1/4 mile
88.39mph terminal

I then plugged in my partly tuned PFC - VVTi tweaks, ignition advance, fueling 4k rpm+ was between 12.8 and 13.3 AFR, I have a very very rich midband which I need to tune but each run it only went through these cells once. The timing is still fairly conservative, knock levels are low for the whole map.

Best run:

2.0745 second 60 foot
14.9645 second 1/4 mile
91.41mph terminal

[shnazzle]

The MAF mod isnt supposed to make the car any faster though.
It's supposed to unleash a bit of midrange torque.

So the rest of the dyno run data would be more interesting. How did it pull in the middle of the 1/4 mile through the gears?

[m1tch]

The MAF mod isnt supposed to make the car any faster though.
It's supposed to unleash a bit of midrange torque.

So the rest of the dyno run data would be more interesting. How did it pull in the middle of the 1/4 mile through the gears?

I found that advancing the ignition made a fair bit of difference to throttle response and overall drivability - switching back to the stock ECU the car felt 'soft' in terms of throttle response and felt lacking low down. I have found however that running an air filter behind the battery also freed up some low down torque even on the stock ECU as its a straight shot into the intake rather than round a few bends.

The car is now running on my Link Xtreme and is currently converted over to a MAP sensor - will be looking to remove the MAF completely soon, although still using it for the intake air temp but have a replacement for that to fit soon.

[Optimus prime]

Throttle response is my main problem along with the gear ratios (that's another story for another thread). Personally I think it has enough HP but it's mid-range power is relatively lacking. I'm going to run a few tests and do a few runs when I get back home on Friday just to ensure nothing is wrong. I also plan on installing my induction kit on Friday after my initial tests to see what I get. next month i'll be installing a new manifold (if Hamish gets stock in) and depending on whats left in the bank i'll get some lowering springs.
thanks for the offer on the PFC but as i'll be learning and playing with it i think a piggyback is going to be the safer bet for me, plus i want to keep the immobiliser, AC and other bits.

[shnazzle]

Throttle response is my main problem along with the gear ratios (that's another story for another thread). Personally I think it has enough HP but it's mid-range power is relatively lacking. I'm going to run a few tests and do a few runs when I get back home on Friday just to ensure nothing is wrong. I also plan on installing my induction kit on Friday after my initial tests to see what I get. next month i'll be installing a new manifold (if Hamish gets stock in) and depending on whats left in the bank i'll get some lowering springs.
thanks for the offer on the PFC but as i'll be learning and playing with it i think a piggyback is going to be the safer bet for me, plus i want to keep the immobiliser, AC and other bits.

Sounds like you want to invest in a bored out throttle body.
That's where all my direct throttle response came from. Along with the Hurricane intake.
Also, ask @Carolyn for the parts list for her engine head-steady. It doesn't make things any quicker but overall response is better because you don't have to wait for the engine to stop rocking around on its mounts.
An emanage blue can be had for cheap cheap and you can do the appropriate MAF compensation in there for an intake kit,and some timing if you see fit.
You can also achieve the same effect as the larger injectors by telling the emanage that you're running smaller injectors. Same as putting larger injectors in and not telling the ecu.

[lamcote]

For what it costs I reckon the MAF mod is worth a try. It seems to be a completely proven option that doesn't mess about with the ECU or cause any MOT emissions problems.

If you do it using the FPR mod it should only cost about £30!

[Optimus prime]

shnazzle - would you have a thread on what you did and your findings? i'm interested!

lamcote - you're right £ for £ the MAF mod seems to be unbeatable.

[shnazzle]

shnazzle - would you have a thread on what you did and your findings? i'm interested!

lamcote - you're right £ for £ the MAF mod seems to be unbeatable.

I can't quote any sources unfortunately  These are just what I've experienced/logged over the years of trying stuff with my car

The MAF mod definitely works and is great bang for buck. It's proven by many many people.
I had the kit, I just never installed it because I ended up putting the eManage blue on instead.

[Optimus prime]

Now you're giving me ideas! i'm going to be new to the world of aftermarket ECU's. Could you point me in the right direction? I've been looking at the Greddy blue but not the instillation of it, as i understand it i'll need some harnesses to connect into the factory looms. what should I be looking for? i'll then need a base map etc etc.

[shnazzle]

Now you're giving me ideas! i'm going to be new to the world of aftermarket ECU's. Could you point me in the right direction? I've been looking at the Greddy blue but not the instillation of it, as i understand it i'll need some harnesses to connect into the factory looms. what should I be looking for? i'll then need a base map etc etc.

You should be able to pick up a blue for peanuts. It's the harness you need that's expensive, unless you hardwire it in. To be fair, there's not that many wires, it's not that good haha.
but anyway, the Boomslang harness will set you back a fair few pennies.
Best bet is to ask on here to see if anybody has a plug/play piggyback up for sale and go from there.
wouldn't worry about a base map. It's not a standalone. The piggyback only adjusts signals, it doesn't create them. So if you plug it in and leave everything blank, it does nothing. Nice and safe

[m1tch]

One thing before you start going towards an aftermarket ECU, what sort of power are you planning on and what are your future plans? I only ask as the 1zz with all the bolt ons might get 10-15% above stock including an aftermarket ECU. Whereas swapping out to a 2zz on a stock ECU will be up to around 190bhp.

Basically just saying that after you swap out the intake and exhaust, any further tuning on the 1zz NA gets very expensive for only small gains.

I am building up a forged 1zz to go turbo - aim is around 400bhp, I have upgraded to a Link Xtreme as it has knock control along with many other options, I have invested in the ECU to help protect my investment in the engine. If you plan to stay NA then look at the 2zz swap, if you are wanting forced induction you could look at a turbo on supercharger on the stock 1zz (which will need a better ECU).

Let us know your overall goals for the car in terms of power and use, I will have my 1zz PFC up for sale soonish (currently sitting next to me) which is a standalone ECU vs an EM blue or EMU - be careful with ECU selection though, not all aftermarket ECUs have support for VVTi.

[Optimus prime]

At the moment i'm looking to stay N/A with the 1ZZ. I want to improve throttle response and gain some power. If I could get up to 160 whp that would be amazing but in reality i think 150 whp is more manageable on budget. 

I will mainly use the car on the road. I might give a track day a blast but that's not what this car is about for me.

I'm really interested in learning how to configure an ECU which is going to take some time. Yes, i'm fully aware I would get better results with a professional tune but that's not what i'm after.

My ultimate goal would be to create my own 6-7 low boost turbo setup which should yield circa 200 HP from reading other posts (more than enough). As I understand it, this would give me great drive-ability on the road. a SC would be nice but budgets are soon stretched, especially when looking at Rotrex.   

[m1tch]

At the moment i'm looking to stay N/A with the 1ZZ. I want to improve throttle response and gain some power. If I could get up to 160 whp that would be amazing but in reality i think 150 whp is more manageable on budget. 

I will mainly use the car on the road. I might give a track day a blast but that's not what this car is about for me.

I'm really interested in learning how to configure an ECU which is going to take some time. Yes, i'm fully aware I would get better results with a professional tune but that's not what i'm after.

My ultimate goal would be to create my own 6-7 low boost turbo setup which should yield circa 200 HP from reading other posts (more than enough). As I understand it, this would give me great drive-ability on the road. a SC would be nice but budgets are soon stretched, especially when looking at Rotrex.   

That's great to know your goals, certainly very achievable, my suggestion would be:

1zz NA

Intake - filter behind the battery (enclosed)
Decat manifold (removing precats)
Free flowing exhaust (I am running a TTE but its not the lightest)
Minor weight reduction

You can then look to get an aftermarket ECU, which should cover maxxing out the car NA but still have the option to run turbo, you will need additional items such as injectors, possibly clutch along with all of the turbo items. Check out Leethesparky's build or his youtube channel spyderlee and see what he has done, he is running on an E-Manage ultimate, think there is also a group buy for a standalone ECU on this forum as well.

You can see from my drag times that the weight does make quite a difference with only a small amount extra gained from the extra power - I know when I was running my PFC vs the stock ECU it certainly felt more driveable.

I would suggest doing a few cheaper intake and exhaust mods first and then look at doing supporting mods such as the brakes, servicing, any suspension work etc before increasing the power output. Tyre choice make a huge difference, as does the tyre pressures so look at fine tuning the car first to your liking - there are a few simple things you can unbolt to remove weight which will help the overall feel of the car as well which is free performance.

[lamcote]

160 Whp is not really going to be achievable from a NA 1zz, certainly not without spending thousands. Even 150 Whp is mega money.

[Call the midlife!]

Doesn't Bernie's make around 150 whp? And that's with 170 bhp.


Sent from my iPhone using Tapatalk

[lamcote]

Yes and how much did that cost?

Then getting another 10 whp for 160 would be eye watering.

[Call the midlife!]

Yes and how much did that cost?

More than I paid for my car...[emoji23]


Sent from my iPhone using Tapatalk

[m1tch]

160 Whp is not really going to be achievable from a NA 1zz, certainly not without spending thousands. Even 150 Whp is mega money.

Just going on the dyno figures posted up vs as stock power of 140bhp - as mentioned tuning the 1zz NA past bolt ons isn't going to give many gains vs a 2zz swap or LPT.

https://www.mr2roc.org/forum/index.php?topic=27521.0

[m1tch]

Yes and how much did that cost?

More than I paid for my car...[emoji23]


Sent from my iPhone using Tapatalk

My Link ECU cost more than my car lol