Tuning Results and dyno graphs

[Luke]

As stated earlier, i agree with mpsgarage, turbo efficiency cant be the cause.
Any ideas on this?

You can't just say "Turbo is efficient to 18PSI". Sure it might be that efficient when it's only flowing a relatively small amount of air, but as the revs increase, and the amount of air flowing increases, the pressure it can push while still remaining efficient drops off. The Standard turbo is DRASTICALLY too small for the MZR engine to make good power in the top end. Mazda have deliberately made it so small so that it has a lot of torque down low. The cars go so well in the lower rev range because the turbo is so small. You will not tune more boost at higher revs, the turbo is flat out.

[nissanman]

I agree with you. But if you look at the compressor map for this turbo it does still seem to be efficient up to 18psi whilst pushing that extra air within a higher rev range...

A compressor map will give you 'boost pressure' by 'RPM' vs 'efficiency'

[Luke]

Do you have a link to the map?

[nissanman]

I'll try grab it and post it up. It's floating around the us forums.
Cheers, has been a good discussion thus far

[VGP]

Cant remember if its this one or not.

[MaN|aC]

i swear u guys tuning in qld need a bloody wind tunnel

[Luke]

I plotted the points on the graph. I'm pretty confident of my calculations. Red line is @ 16PSI, Green line is @ 19PSI. You can see the red line goes nicely straight through the efficient part of the map, and falls off the cliff at 5500 RPM. 19PSI is another story, only really gets efficient around 4500. All the numbers above that are hypothetical because it cant get to them anyway due to it being to far outside it's efficiency range. Pretty conclusive to me. The numbers don't quiet line up to the markings, but you get the idea.

[nissanman]

Thats the map cheers for that,

Nice plotting mate. I do agree with you. But if you look at the "19psi" point of the map... Ive put a red and orange ring around where i actaully think its still within its efficiency range. Its not great, i know lol but still able to push about 18psi i believe and not create a mass amount of heat...
Especially seeing as though our 6Speed boxes need changing up quickly.

Do you agree? Or sort of see where im coming from?

Please dont take anything im saying as an attack neither is it aggressive. I do actually enjoy learning and discussing matters like this with people.
The only way to learn or readjust what we know is by research and talking to others that have the knowledge.

Cheers

[Luke]

I can see where your coming from but I can't see the car actually getting to that point. If you imagine the lines falling down as they go past the most efficient point, they progressively make themselves worse.

---------- Post added at 09:13 PM ---------- Previous post was at 09:05 PM ----------

I would imagine the curves look more like this.



---------- Post added at 09:20 PM ---------- Previous post was at 09:13 PM ----------

I cant explain it very well, sorry, but I will try to prove it. I'll wire my waste gate shut and film it and show you my car only pushing 14PSI above 5500 RPM. I'll just have to be careful lower in the revs.

[nissanman]

oh yea I see what you mean. You might be right.
Would be interesting to see your turbo spool to maximum with wastegate shut.
And yes perhaps be very careful from 2,500 onwards lol

I can see where your coming from but I can't see the car actually getting to that point. If you imagine the lines falling down as they go past the most efficient point, they progressively make themselves worse.

---------- Post added at 09:13 PM ---------- Previous post was at 09:05 PM ----------

I would imagine the curves look more like this.



---------- Post added at 09:20 PM ---------- Previous post was at 09:13 PM ----------

I cant explain it very well, sorry, but I will try to prove it. I'll wire my waste gate shut and film it and show you my car only pushing 14PSI above 5500 RPM. I'll just have to be careful lower in the revs.