R/R Graph

[Mr Bognor]

What is the below graph ???

I have a Fly wheel one a wheel one a AFR one but not sure on this one ???

[jimGTS]

power and boost

that says to me nice stable boost and 0.9-0.95bar

[Mr Bognor]

This is what i thought but is the power not a bit hi at under 1.0 bar of boost .

Alan

power and boost

that says to me nice stable boost and 0.9-0.95bar

[jimGTS]

its good power for the boost.

how do you mean "a bit high"?
i would be worrying more if it was "a bit low"

oem ecu?
stock ignition timing?

got a pic of the AFR?

perhaps a weak fuel pump is leaning the car out a little, hence the good result.

i assume 240-ish at the wheels power wise??

[Mr Bognor]

Just thought it would be a bit lower with only that boost but the car had a stage 2 recon turbo .

Below is the AFR and the wheel BHP was 244.9

its good power for the boost.

how do you mean "a bit high"?
i would be worrying more if it was "a bit low"

oem ecu?
stock ignition timing?

got a pic of the AFR?

perhaps a weak fuel pump is leaning the car out a little, hence the good result.

i assume 240-ish at the wheels power wise??

[jimGTS]

those afr's do look leaner than usual, which isnt a bad thing as dont look dangerous.

but i would definitely say this is the reason for the additional power.


oem ecu?
oem ignition timing?

these could also be helping.

i wouldnt be overly concerned, pleased if anything.

though i would be watching out for your AFRs if you plan on increasing boost further.

[Mr Bognor]

Well i was going to install a MBC and up the boost to 1.15 BAR .

Do you think this will cause a problem then and is it worth it ?

Car has the below so i think

Exhaust & decat
HKS air filter
Grade 7 plugs
all new ignition coil dizzy etc
Stage 2 turbo with cut back exhaust blades and 360 thrust bearings
Greedy style intercooler with sprall fan

ECU and ignition i would guess are std

those afr's do look leaner than usual, which isnt a bad thing as dont look dangerous.

but i would definitely say this is the reason for the additional power.


oem ecu?
oem ignition timing?

these could also be helping.

i wouldnt be overly concerned, pleased if anything.

though i would be watching out for your AFRs if you plan on increasing boost further.

[jimGTS]

"would guess"?

i would say worth checking this out

you may have a blitz or mines ecu (cool)
and/or your base timing could be advanced a degree or 2 (not so cool)

base timing, you just need a timing gun and a paper clip, easy enough to check.

[Mr Bognor]

There was no mention of this when i got the car and all of the other mods were listed .

I will check but if it is on the std ECU and Timing will a + of 0.4 bar knock out the AFR too much ?

"would guess"?

i would say worth checking this out

you may have a blitz or mines ecu (cool)
and/or your base timing could be advanced a degree or 2 (not so cool)

base timing, you just need a timing gun and a paper clip, easy enough to check.

[jimGTS]

noone would usually declare advanced ignition timing.
it could even be done by mistake. but too much and you could be prone to det and knock.
its worth checking.

0.4bar yes it would! would be on the brink of oem fuel cut also.
but you mentioned 1.15bar, this is only 0.2bar more (not 0.4bar) than what your running.
it could lean it out more sure (evne 0.2), could it lean out too much though; only an afr gauge or another dyno run would tell you.

[Ryan S]

just pull back the boot carpet, you will see right away if it's an aftermarket ECU

[Mr Bognor]

Yes sorry i was going to set it at 1.15 bar so may check the ECu and timing then fit a MBC then set it up to 1.15 bar then have one last go at SRR on the rollers to see if it is ok .

What would be an ok level if it is set at 1.15 bar on the AFR chart

noone would usually declare advanced ignition timing.
it could even be done by mistake. but too much and you could be prone to det and knock.
its worth checking.

0.4bar yes it would! would be on the brink of oem fuel cut also.
but you mentioned 1.15bar, this is only 0.2bar more (not 0.4bar) than what your running.
it could lean it out more sure (evne 0.2), could it lean out too much though; only an afr gauge or another dyno run would tell you.

[Mr Bognor]

Ok will have a look tonight with some pic .

Alan

just pull back the boot carpet, you will see right away if it's an aftermarket ECU

[Marf]

All looks fine to me

[Mr Bognor]

But if i put in a MBC and up to 1.15 this may upset the AFR .

What is a good / ok reading on the AFR as this is the bit im not sure about ?

Alan

All looks fine to me

[Marf]

But if i put in a MBC and up to 1.15 this may upset the AFR .

No, it won't. The ECU is mapped to run rich all the way up to fuel cut.

You won't run the risk of leaning out. If anything I'd bet you'll see a richer AFR than at your current boost levels.

If this concerns you, it's programmable ECU time

[Mr Bognor]

This is what i thought reading bits as i thought 13.0:1 was a rich mix and my car at the me is at 10.4:1 @ 6900 RPM .

Think the best thing is to fit it set the boost then have another Dyno and if its still at around the 10.4:1 then this is all good .

One other note as its not super rich at the mo will upping the boost make it more rich and drop BHP or is not the way it works as it will be getting more air ?

Alan

But if i put in a MBC and up to 1.15 this may upset the AFR .

No, it won't. The ECU is mapped to run rich all the way up to fuel cut.

You won't run the risk of leaning out. If anything I'd bet you'll see a richer AFR than at your current boost levels.

If this concerns you, it's programmable ECU time

[Marf]

It is richer than stoich for sure, but 13:1 is by no means a rich mix. Most turbocharged OEM cars tend to run around the 11:1 mark.

If I was going to have my MR2 mapped, I'd have the AFR mapped to around 11:1 on boost.

[jon_st205]

Agreed 11 is good, 12:1 gives good power but no margin for safety really. 10.4:1 is a little low so is costing a little bit in outright power, but is also very safe. Most 3SGTE's on standard ECU's run <11:1.

Jon

[Mr Bognor]

Ok so it is rather rich at the mo then so more air ( more boost ) will be ok and if anything will lean it out a bit to a better level .

So 10.4:1 is a good rich mix ?

Alan