Andy's Rev 3 Turbo - Project complete.

[C35Rob]

I can only echo ashley's comments.. it makes good torque then it drops off a cliff at 5k

it does seem very rich (10's pretty much across the board is very fat) and retarded though. definitely don't be led down the rabbit hole of blaming the .50 compressor housing for the lack of power over what you wanted/expected.

without saying "I told you so" this does highlight the downsides of the way you chose to have the car mapped, had it been dyno tuned you could have potentially have fiddled/tuned the set up on the day.

you say the spark was getting blown out with copper plugs? what gap was that with? there's no reason iridium/platinum plugs should outperform genuine copper plugs that are gapped properly and in good condition - in fact the "posh" plugs can be a problem themselves as the tip is so fine it can't dissipate the heat and becomes a hot-spot, which itself can lead to detonation issues - this video explains it

https://www.youtube.com/watch?v=dgFVN9iMnLg

again as ashley said, COP would be nice, but isn't essential, people have made plenty of power on the stock ignition system for the last 20 or so years - it works fine when it's in good condition.

anyway, all is not lost, you have a baseline, some things to work out over winter and come back next year with a finished product - try not to be too disheartened.

[mr2toby]

Any other mr2's run ?

[ashley]

Thinking on this- I reckon you need to redo your base ignition timing back to 10deg BTDC...it would be very interesting to see your ignition map, it must have a load of retard in there to cope with such advanced base timing...I wonder if this is then impacting how they mapped ignition under load, leading to an overly retarded ignition map...?

[androo007]

Thanks a lot guys, really appreciate the input. Really peeved at the moment but let's see if we can't sort it eh?

OK here's the rundown...

I assume the housing is the standard .62 hot side? It has the 76mm exhaust wheel.

Cold Side: Agreed - everyone has said the .50 A/R cold side is perfectly fine and wont be a big restriction

This is the interesting point: fuelling was set to 11.5 AFR across the board (target) and ignition I think was around 18 deg.

IIRC he was hearing knock at higher revs at 1.7 so dropped the boost to 1.5. Although by the looks of it there's something else at play. Compression of pistons was 8.0:1 standard HG.

No water / meth: tuner said that temps were ambient + 10 degrees so never got hot. I think actually it may have been 32 deg not 23 - can't remember.

I've spoken to Fensport today who do a lot of MR2's: they NEVER dyno tune apparently. HOWEVER, I've booked in with them next Monday to do some detective work and a remap.

They confirmed I would have to have iridium plugs gapped to .6 (in there now) and that the standard ignition system is good for 700hp (as Rob rightly said). Although they are road tuners only... they have a good reputation and otherwise I'm not sure who to turn to at the moment. They're going to spend a couple of hours in the workshop checking all the basics before gong on the road - even they agreed straight away I am 100hp down on what they'd expect.

They suspect the cams / timing being out.

Interestingly Martin, they were the second person to ask if my cam timing is correct, along with your thoughts Ash on the ignition timing. I guess you mean this by measuring with a timing gun, right? If either of those are out I'll not be a happy bunny.

Ash mate I'll take a laptop home tonight and get the map off for you, thanks very much for the kind offer.

[C35Rob]

how was he measuring AFR's when he was mapping? do you have a wideband installed or was it his own kit?

how was he measuring inlet temps?

your turbo will have either a 55,56 or 60mm turbine wheel, the 76mm is the compressor wheel - although that's not particularly pertinent at the moment.

we need to confirm what he/you mean by 18 deg timing, is that the base timing (i.e set with a timing light by rotating the dizzy) - which should be 10deg btdc at idle, or if he means that's the number he's pumped into the map when it's on full chat (I'd be interested in having a look at the map too tbh)

you say you've got 8:1 pistons, do you know if the block and/or head have been refaced at any time?

[androo007]

AFR's were measured with a wideband - his own kit.

Inlet temps measured by an fast speed IAT sensor placed just before the throttle body (Link measures this all the time).

+18 deg on full chat to baseline.

Block was completely unopened, never resurfaced. head was just skimmed, nothing taken off. Will get it for you both guys

I'm sure when I was last up at Petes he checked the timing with a light and it was spot on.

I have confidence in my mapper - I think there is another issue at play....

Seems this is quite the connundrum!

[shane34]

Keep at it Andy, Fensport mapped the car I have now when Julian had it, you will be in good hands for sure. road tuned.

Also noticed you mentioned 32 degrees? this would be 20+ ambient? I'm sure it was quite cold around 10 degree where I live on Saturday

[ashley]

+18 deg on full chat to baseline.

So he retarded ignition by 18 degrees at full chat, i.e. 10 degrees BTDC at idle (base timing), retarded back to 8 degrees ATDC at full load? Need to see your map...but if that is the case, it certainly explains where your missing power is.

You really should get it mapped on a dyno

[androo007]

Thanks Shane, thats encouraging.

Ash man i completely agree, it is my preferred option but at the moment I dont know who is local to me who i'd trust via dyno tuning tbh.

With the mapping I'm not educated enough to say, I think im guessing at this point. I'll send over the map later to you and Roband you can tell me what toddle i'm typing

[ashley]

[androo007]

Sorry guys or got to bring laptop home with me - will be tomorrow. Thanks for all the help so far guys

[androo007]

Map coming this afternoon...

Speaking to my tuner he is suspicious of the dyno - and thinks that at 5k the dyno runner partially took his foot off the throttle.

Why?

* ECU install timing was checked witht eh gun and calibration - 10 deg perfect

* Cams are fine and in time

* Boost gauges, O2 sensors, all equipment re-checked and confirmed within spec and fine.

Key here is that you can see the boost drops from 1.7 bar to 1.5 - this is where 3/4 throttle is coming in... and funny enough where the power dies off.

Also, AFR's are mapped at WOT for 11.5 - and partial throttle is richer.

Starting to become clear....

driving the car it just pulls and pulls, its a quick car. boost does not bleed off or torque dive off.

Anyway.... tomorrow night we'll find out.

I maintain my confidence in the mapping in the car and at this point in time, but keen to see whats going on! Just one idea.


Maybe its bad to speculate

[ashley]

Cool beans....send me some of your data log files as well....

Don't get why a dyno operator would lift off...how many power runs did he do and did you see similar results each time??

[androo007]

3 runs, similiar power

He was very quick to offer up his own services to take a look at a cost....

Maybe i'm speculating and grabbing at straws..

[shane34]

That's very disappointing if it is true, you should be able to tell with the logged data? If still available surly the throttle position sensor would show slight let off Woth the throttle position?

[androo007]

I dont think I have logging, do I?

[ashley]

Fueling table looks sensible, but it should be if it was lambda tuned...worth considering adding a wideband sensor to your setup and running closed loop. You could also be running smaller injectors...

I don't understand what he's done on the ignition side though...all looks as you'd expect until you get above 4k rpm, and over 1.4bar of boost...then it's been flat line retarded across the board. Ordinarily (all engines being different) I have seen timing advancing with rpm...might be worth asking if this is intentional.

I'd also prefer to see 1.5bar (being your target boost) as it's own row in the table...it currently jumps from 1.4 to 1.59, so the ECU is interpolating between these pressures....not ideal if you are targeting 1.5bar.

To be honest- you need to get it on a dyno and map ignition, my "guess" is that it started knocking at 1.6bar, so he pulled timing back and then left it there...but there may be a valid reason for the flat island of retard in the top end of the table...

[androo007]

Thanks Ash.

You're pretty spot on. He said that he saw some knock right at the top (7k) so pulled the timing a little for safety.

To echo your comment - Whats interesting to me are those ignition values - pretty low across the board i'd say?

However...... target boost should be 1.7 bar across the board - so i guess that should have its own row? Not sure why those values are there....

Do you have your ingition map for comparison? (just for my learning)

Injectors are only 800's - surely the right size required for the turbo when running as expected?

He's suggested that with stronger ignition / spark we'd be able to add more timing - agree?

[androo007]

And the one mystery that still baffles me.... if you look at my boost, why does it settle on 1.5 bar and not 1.7?

[ashley]

Yeah- his timing correction was potentially a little heavy handed, but again- that's one of the things you struggle to play with safely when road mapping (in my opinion). That amount of retard will definitely be reducing the torque the engine is producing...from memory 2 degrees of advance made something under 100hp extra at the same boost (maybe 80hp, can't remember- it was a long long day!)

The figures are ball park what you'd expect except top end under load, remember they are degrees before top dead centre- so the larger the figure, the more advanced they are.

For comparison my current setup is running ~14.6 degrees before TDC at 2.4bar of boost at 8k rpm...and that was in a hot dyno cell, so intake temps ~35c, maybe a bit more. But our engines are very different...so not really a fair comparison.

Not sure a stronger spark would help- my guess is either it's overly retarded at the top end, or there is another reason it is knocking when he put timing into it- and that's what you'd need to investigate....either way: the only remedy is to do some more tuning, and save yourself some cash- do it on a dyno where you can look at timing properly.


I'm struggling to find the boost aim table...not overly familiar with Link...will come back to you....