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(Post Link) post #1 of 25 Old 17-02-15 Thread Starter
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1.9 8v Mjet with GT1756 hybrid, low performance?

Hello all,
I don't normally post on here because I dont actually have an alfa, I have a grande punto JTD, but same engines ey,
I've got a hybrid gt1756 on my car, but I only have 198bhp and 168whp... which is awful.
I do have 330ft lb but the car is just, slow.

All mapping was done at rs tuning (this is my 3rd turbo on this car due to bad mappers so thought I would splash out on the mapping) And he told me the car's injectors where maxing out, and he only got that fly wheel power with a bit of smoke.

I can't see how injectors are maxing out, the car has so little power compared to what I was expecting,
Do I really need 112% injectors?

Fun fact, my last turbos exhaust shaft snapped, not helped by the fact the previous quantum tuning map put so much fuel into the cylinders it couldnt burn it and it ended up in my oil.
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And what were your expectations?

I would say your results are quite OK considering the setup.
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(Post Link) post #3 of 25 Old 18-02-15 Thread Starter
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Originally Posted by TribesMan View Post
And what were your expectations?

I would say your results are quite OK considering the setup.
I was looking for a higher whp, the car is he same as it was with just a decat and map ,
I was hoping for 210 to 220 at the fly, and it's been done before, just can't understand what's maxing out on mine
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Well it is not a problem to reach 220HP at the flywheel on a 8V engine with a proper setup.

Increasing compressor size and raising boost is unfortunately not enough IMO. You are most probably suffering from excessive back-pressure because the turbine wheel exducer is too small for desired power.

But it is hard to say for sure without seeing the map.
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Few things, 16v 1.9 with standard gt1747 will max out at about 200BHP at 2.6bar (tried and tested and numbers from the dyno match the theoretical numbers).
You have 8v engine so you will need higher boost to get same amount of airflow.
Injectors do not max out as such - you can get them to inject as much fuel as you wish - but it takes time, and you have limited amount of time to inject (and it gets worse with higher RPM) - so higher flowing injectors might help if you have air flow to back it up (what does your airflow reading say?).

I would say that you need to do some logging (actual airflow, manifold pressure and temperature, fuel rail pressure and injection time) and then post the logs here.
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Injectors do not "max out" literally, but they get very inefficient when you go over their capabilites.
When you are pushing them into high IQ the time needed for extra fuel is not anymore proportional to the fuel increase. So you might need 25% more time to inject 10% more fuel. And that is not acceptable on a diesel.

So you can say that injectors "max out", because even though you can inject more, that fuel is injected way too late.
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(Post Link) post #7 of 25 Old 19-02-15 Thread Starter
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Originally Posted by jacekowski View Post
Few things, 16v 1.9 with standard gt1747 will max out at about 200BHP at 2.6bar (tried and tested and numbers from the dyno match the theoretical numbers).
You have 8v engine so you will need higher boost to get same amount of airflow.
Injectors do not max out as such - you can get them to inject as much fuel as you wish - but it takes time, and you have limited amount of time to inject (and it gets worse with higher RPM) - so higher flowing injectors might help if you have air flow to back it up (what does your airflow reading say?).

I would say that you need to do some logging (actual airflow, manifold pressure and temperature, fuel rail pressure and injection time) and then post the logs here.
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Originally Posted by TribesMan View Post
Injectors do not "max out" literally, but they get very inefficient when you go over their capabilites.
When you are pushing them into high IQ the time needed for extra fuel is not anymore proportional to the fuel increase. So you might need 25% more time to inject 10% more fuel. And that is not acceptable on a diesel.

So you can say that injectors "max out", because even though you can inject more, that fuel is injected way too late.
Well that's a pain, the car is just slow tbh and now the 2nd hybrid is starting to howl, I can't see why it's on its way out, I wouldn't blame rs tuning.
Can you get uprated injectors on the 8v?
Sorry I can't make a detailed reply to everyone, at work atm!
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Quote:
Originally Posted by kyle_xo View Post
Well that's a pain, the car is just slow tbh and now the 2nd hybrid is starting to howl, I can't see why it's on its way out, I wouldn't blame rs tuning.
Can you get uprated injectors on the 8v?
Sorry I can't make a detailed reply to everyone, at work atm!
Turbo can die for few reasons:
- wear and tear (probably not in this case)
- manufacturing defects
- running it too fast (at higher boost/flow than it was designed for)
- running it too hot (because of rich AFRs and)

in your case i would suspect a bad map with boost set too high (not that many people understand compressor maps and know how to work out the numbers and then actually use them - and as i've found out myself it only takes few seconds to kill the turbo) and therefore overspeeding it - it's not hard to do if you have restrictions in air path

You can get uprated injectors for anything - it's just a matter of spending money on it (10-15% is going to be fairly cheap)

Also quite important question - does it smoke?
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Big compressor small turbo, high exhaust manifold pressure, high exhaust gas temperatures... those things can lead to premature turbo failures.

BTW how much boost are you running with that turbo?

But there are so many other questions. How high is fuel pressure, start of injection, AFR...

Can you get the map from your car and post it so we can review it?

Upgrading injectors on a m-jet is really tough job. Problem is you need to get them tested and calibrated to get new calibration codes, or else the engine will not run optimally. But when you install bigger nozzles there is no way to get calibration codes for that.
Without right calibration codes you can loose up to 20BHP.
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Quote:
Originally Posted by jacekowski View Post
Turbo can die for few reasons:
- wear and tear (probably not in this case)
- manufacturing defects
- running it too fast (at higher boost/flow than it was designed for)
- running it too hot (because of rich AFRs and)

in your case i would suspect a bad map with boost set too high (not that many people understand compressor maps and know how to work out the numbers and then actually use them - and as i've found out myself it only takes few seconds to kill the turbo) and therefore overspeeding it - it's not hard to do if you have restrictions in air path

You can get uprated injectors for anything - it's just a matter of spending money on it (10-15% is going to be fairly cheap)

Also quite important question - does it smoke?
I went to rs tuning mainly because I've had such a bad experience with bad mappers in the past, 2 maps before this one, the hybrid failed litrally 1 day after the map, turned out the sump was full of oil, injectors where being worked 40 % over their optimum according to rs tuning.

When he put a base map on it, it didnt smoke, he said he wouldnt be able to get it past 190bhp without a bit of smoke, he said he upped the fuel rail pressure a bit to get that power but the downside would be a touch of smoke (no where near as much as the last one)



Quote:
Originally Posted by TribesMan View Post
Big compressor small turbo, high exhaust manifold pressure, high exhaust gas temperatures... those things can lead to premature turbo failures.

BTW how much boost are you running with that turbo?

But there are so many other questions. How high is fuel pressure, start of injection, AFR...

Can you get the map from your car and post it so we can review it?

Upgrading injectors on a m-jet is really tough job. Problem is you need to get them tested and calibrated to get new calibration codes, or else the engine will not run optimally. But when you install bigger nozzles there is no way to get calibration codes for that.
Without right calibration codes you can loose up to 20BHP.
The turbo is running 1.7bar (it's had one dyno run at 2 bar)
And as for those other questions, I'm not sure how I would be able to provide you with that info.


Out of curiosity, is it safe to fit the injectors (if i can find somewhere that can provide and uprate them, if you know anywhere?) and then drive to rs tuning unmapped to have them mapped in etc?

Cheers for all the replies you all seem to know your stuff!
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I would expect a maf of over 1350mg maf on my jtdm 16v at 2700mbar.
so example 1350mg air divided by say 95mm3 of fuel or 79.8mg/I of fuel gives afr 16.9
are you using 95mm3 ?
if you already are and want more you need more boost or more maf from better intercooler say.
also as above you need derestricted exhaust and possibly larger turbine side to reduce egt.
for sure 8v head wont flow well at top end, so boost would need to probably need to be higher than required to force air in.
I don't like your low whp number for high bhp number 30hp losses seems high to me ?
car should feel pretty quick with real world 180-190hp and as also said that compares pretty well to what ive seen with 8v with hybrid . I think that's what cree ended up with
https://www.alfaowner.com/Forum/tunin...o-upgrade.html
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Originally Posted by sussexa View Post
I would expect a maf of over 1350mg maf on my jtdm 16v at 2700mbar.
so example 1350mg air divided by say 95mm3 of fuel or 79.8mg/I of fuel gives afr 16.9
are you using 95mm3 ?
if you already are and want more you need more boost or more maf from better intercooler say.
also as above you need derestricted exhaust and possibly larger turbine side to reduce egt.
for sure 8v head wont flow well at top end, so boost would need to probably need to be higher than required to force air in.
I don't like your low whp number for high bhp number 30hp losses seems high to me ?
car should feel pretty quick with real world 180-190hp and as also said that compares pretty well to what ive seen with 8v with hybrid . I think that's what cree ended up with
https://www.alfaowner.com/Forum/tunin...o-upgrade.html
Truthfully mate the stuff about maf there means nothing to me, i've never got this technical before, That's all new info to me.

I don't understand why my whp is so low either!
I do have the usual mods though, larger intercooler (stock grande punto ic was tiny) and a complete straight through exhaust apart from the mid box which I left in (main thing is no precat)

I'm on the look for better injectors atm, 112 percent should do, and I will see from there
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1.7 bar should be a safe boost for that compressor wheel. But there is still a question how good is boost control, do you get a lot of overboost? How high is EGT? How is the EMP? Was turbo balancing done properly?
Hard to say what exactly could be the reason for turbo failures without knowing all the details.

Now to the performance part... With 1.7 bar boost I think you will not be able to gain much more than 210HP. And you need everything to work optimally to get there. Even though you have a bigger compressor, that does not solve the problem of having too small turbine exducer.
Stock turbine wheel is a big problem if you want to go over 200HP.
Fitting bigger turbine would help a lot, something like GTB2056 will get you up to 230HP.

I think your injectors are not a problem. From my experience those injectors will go up to 230HP with 1750bar fuel pressure if everything else is OK.
Also if you are getting light smoke at the moment, that means that most probably injectors are not an issue, as there is more fuel that could be burned.

But there are so many unknowns in your equation that is very hard to say what exactly is the problem.

Its not everything in bigger injectors and injecting more fuel. There are much more things to be considered.
Without seeing what has been made in the ECU it will be hard to come to a conclusion.
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1.7 bar should be a safe boost for that compressor wheel. But there is still a question how good is boost control, do you get a lot of overboost? How high is EGT? How is the EMP? Was turbo balancing done properly?
Hard to say what exactly could be the reason for turbo failures without knowing all the details.

Now to the performance part... With 1.7 bar boost I think you will not be able to gain much more than 210HP. And you need everything to work optimally to get there. Even though you have a bigger compressor, that does not solve the problem of having too small turbine exducer.
Stock turbine wheel is a big problem if you want to go over 200HP.
Fitting bigger turbine would help a lot, something like GTB2056 will get you up to 230HP.

I think your injectors are not a problem. From my experience those injectors will go up to 230HP with 1750bar fuel pressure if everything else is OK.
Also if you are getting light smoke at the moment, that means that most probably injectors are not an issue, as there is more fuel that could be burned.

But there are so many unknowns in your equation that is very hard to say what exactly is the problem.

Its not everything in bigger injectors and injecting more fuel. There are much more things to be considered.
Without seeing what has been made in the ECU it will be hard to come to a conclusion.
I don't know about overboost, or what my egt is etc unfortunately.
the turbo i have has been used on a vauxhaull astra to make 220 odd bhp so I cant imagine the turbo being the limiter, it will handle 2 bar no problem apparently.

I'd love to be able to post up the map here but I'm not able to do that, I have no idea why I can't get more power, I'm not very satisfied with the current power output either.
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IMG_20150204_0002~2.jpg

This is my current graph btw

2015-02-11 01.04.27.jpg

And my oddly low whp

I might be able to get the map on here soon
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If the second graph is wheel horse power then it looks ok, 16V will make around 200BHP at the flywheel, with 30BHP losses that gives you around 170BHP at the wheels.
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(Post Link) post #17 of 25 Old 04-06-15 Thread Starter
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I finally got my map of my car lol

Last edited by kyle_xo; 05-06-15 at 18:29.
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Well... I have seen worse, but this one is pretty bad...

All limiters removed and +35% on injection duration. Brave
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I don't know enough to comment , but also I don't see why remove limiters or raise in flat line.
not sure method on injector duration, why not just change highest column and recalculate for a higher figure
drivers wish maps look odd to me massive spike near 100% pedal
smoke maps look very low
why no fuel pressure mods?
how long does this sort of map take ? or is it generated on some program ?
arnt you going to need to mod the vnt maps ? for your turbo.

and re reading above from the rolling road printouts ? is this the map that was on the car for that dyno ?
and to confirm again, was that dyno run the 145whp, and the printout above the corrected flywheel one ?or 2 separate runs.

example for starters
what does this feel like to drive stock until foot mashed to floor then woohoo
drivers wish xo 2.png
for an extra 5 mins you could have this
drivers wish xo.png
as I said im not a pro/working mapper but this seems more logical.

Last edited by sussexa; 04-06-15 at 19:35.
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Well... I have seen worse, but this one is pretty bad...

All limiters removed and +35% on injection duration. Brave
Really???
its been mapped at what i would call and many others would call one of the best places in england, it took 6 hours to make that map, and was constantly checked on the dyno dynamics dyno which is probarly the only dyno i trust.

in reply to the 2nd reply, the car pulls dont get me wrong, but its always felt like vnt isnt right, its not nice to drive normally, i mean slow round a city etc, it feels like its all or nothing,

I paid just under 500 for that map... :/ I knew it could have been better

i'm not too sure where you have got 145whp from, after ading a 2.5 inch from the turbo back (I had cracked my manifold and my new manifold is warped, and its leaking like a *******)
These are my new graphs, yes that dyno was for this map, and now this map + new exhaust:

(the whp graph shows a boost line too

edit: Ive had to deal with injector duration problems before, i blew my last turbo when a quantum tuning reseller caused all my fuel to end up in my sump... the ca has sounded like a bag of nails ever since
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Last edited by kyle_xo; 04-06-15 at 23:18.
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I don't know what they did during that 6 hours long mapping session, but crazy mods like this couldn't have taken more than 1 hour to make.

The main problem that I see, is that only boost and fuel are raised in this map. Mostly to the limit.
But there is much more that needs to be done before you get everything out of it.

SOI is almost stock, VNT has not been changed, fuel pressure is stock.

I wonder how is it even possible to get 200HP with map that bad
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also cant imagine that map took long to make, I really cant understand what they were checking and altering unless it was the percentage increase on injector duration.
as tribesman says soi is only 1-2 degrees advanced top end yet injectors are spraying 350 to 500 microseconds longer.
I would love to see egt temps
also the boost is requested at 2750mbar upto 4500revs but you are only at 1.6bar so 150mbar low and only maintains 2750 around 3000revs, I think you need more boost than this to make safe /real 200hp
what size 56mm compressor wheel do you have(inducer)
it should have no issue making boost in the higher revs.
even the vnt maps would take countless hours to map log map log to get ideal(unless one of the Vauxhall guys like nutron or littleteapot can let you have a modified vnt map, as they've done many hybrids(if they alter their vnt maps))
ok end of the day itsdoing reasonable power, I don't think 200hp more like a real 185-190hp
for the hardware you now have I think you could get more but not with a map like that.
I would be fitting an egt probe and gauge asap for safety sake, and start to learn the mapping yourself, I think after a while you could make better yourself.

try joining here
www.ecuconnections.com ? Login
read the rules
introduce yourself
upload that map here
www.ecuconnections.com ? Login
then start you own map build.
I don't think they will be so polite about that tune.
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sorry i dont have time to repy to your full messages atm, thanks for the replys though it makes for an intresting read, he said he setup the vnt to as best he could get it,
I just wish I had a decent map on the car, i thought this was the best of the best, and the drivability factor was just a side factor to having a bigger turbo
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heres a duration map extended to 100mm3 and calculated
xo map duration 100mm3.png
that map on yours is still a fair bit higher so your injecting at least +100mm3
edit
actually worked backwards and i think those top column durations of yours work out at
800bar=118mm3
1000bar=117mm3
1200bar=118mm3
1400bar=118mm3
1600bar=121.5mm3
1800bar=123mm3
wow
someone else check ?

what is mod at 007fc2 ?

im pretty sure vnt map is not altered between 2 maps supplied

Last edited by sussexa; 05-06-15 at 13:23.
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I had RS Tuning mapping before I started doing the job myself and they really have no idea how to map. They probably did raise rail pressure the way they did it on my, by rescaling the sensor range to fool the ecu into using higher pressure like a tuning box. They don't know how to control vnt and you'll likely see big boost spikes if they try to raise pressure.

I wasted a lot of time and money there long ago and it is just an unfortunate they are not a specialist on this engine and just use the generic quick map methods to make money.
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