RED X19

Bjorn Nilson said:
This I do not understand. -Janis bigger engine should perform better than mine at same boost.
Click to expand...
I imagine there can be lots of little differences that can make the power output change between the two engines, even at the same boost. Think in terms of efficiency; both having the same boost level but maybe one engine can use it better due to greater efficiency. Plus there may be differences in the tune settings, the charge temperature, the exhaust system, etc, etc. Even the dyno (rolling road) test results can vary a lot between two facilities, especially on different days with different weather conditions, etc. Simply too many factors involved to make a side by side comparison.

About the size of the two engines, if I recall one is 1300cc and the other 1600cc. I know in Europe many new cars are available with several engine choices, sometimes with as little as 100cc (or even less) difference. In America you don't see that, so to us a difference of a couple hundred CC's isn't significant. And maybe the difference between 1300 and 1600 CC's is not enough to make a huge change in power output?
 
Bjorn Nilson said:
Yes I have curves @1bar. I will post them tomorrow.
Click to expand...
2021_03_06 18_15 Office Lens.jpg
 
Maybe Janis can overlap this with his curve to see how they compare.

What I really like about all of the curves from both engines is how the torque band is so high, wide, flat, and carries out to the end. Typical non-turbo ("NA") engines cannot produce this kind of torque (except maybe diesel as you said). And a strong torque curve is what really matters. This is a good example of why I would prefer to build a conservative turbo engine rather than a highly modified NA engine for a street car; the turbo version will have greater usable output, be more reliable, and cost less to build.

If my stock 1500 engine with a UT turbo makes anything close to these two engines then I will be extremely happy.
 
Just a simple look by eye, the "HP" curves are not that much different. The slightly bigger turbo moves the power up a bit in the RPM range. But the "torque" curves - especially in the region around the arrows (below) - are more significant. Maybe this is the difference from the engine sizes? If so then it is more than I thought (at least there). But they are also two completely different turbo designs. So that may make a large change in how they affect the power bands (e.g. the compressor maps).

8648B.png


Janis, are both charts the same scale on the left (difference in numbers and spacing on the graph)?
 
Dr.Jeff said:
Just a simple look by eye, the "HP" curves are not that much different. The slightly bigger turbo moves the power up a bit in the RPM range. But the "torque" curves - especially in the region around the arrows (below) - are more significant. Maybe this is the difference from the engine sizes? If so then it is more than I thought (at least there). But they are also two completely different turbo designs. So that may make a large change in how they affect the power bands (e.g. the compressor maps).

View attachment 44148

Janis, are both charts the same scale on the left (difference in numbers and spacing on the graph)?
Click to expand...
Yes same, just didn’t crop them into jpeg :D asked girlfriend to crop 😅
1AFDAC8B-5E4B-499F-A04E-2877936F2F36.jpeg
 
I would like to see some other 1.6 8v turbo for comparison, can’t find on google on fast search
 
mkmini said:
I would like to see some other 1.6 8v turbo for comparison, can’t find on google on fast search
Click to expand...
Maybe there aren't too many existing. Definitely none over here. Turbos on factory engines were mostly diesels for a long time. Mainly in more recent years before they started putting them on petrol engines. So I'm guessing those are likely to be more modern engines with 16 valves, etc., and the aftermarket usually supports the most common demand, like upgrades for the UT/Punto GT smaller engines (not 1600cc).
 
Dr.Jeff said:
You may have one of the only ones that exists?
Click to expand...
Definitely not, on fiatforum.com few years ago found anothers. As I understand it’s one of the choices between Punto GT owners - to change their 1.4 turbo for 1.6NA and add turbo system..
 
mkmini said:
Definitely not, on fiatforum.com few years ago found anothers. As I understand it’s one of the choices between Punto GT owners - to change their 1.4 turbo for 1.6NA and add turbo system..
Click to expand...
That makes sense. Because we never saw any of those cars or engines here, a turbo 1.6 SOHC really doesn't exist.
 
I am confused about the figures. Janis impressing low rev torque is probably because of the bigger displacement. I guess the lower power at higher revs is caused by lack of air. Just guessing, but I think Janis engine has a breathing issue. It could depend on smaller exhaust valves, cam lift (mine has 9.5mm lift) and restrictive exhaust (mine is 3" with a high flow muffler). Also, Janis IHI turbo is made for a smaller engine (1.3l) and maybe it cannot feed enough air, but my Mitsubishi is designed for a 2l engine.
The IHI turbo can be rebuilt with a bigger compressor. I didn't do it becsuse the cost would have been higher than buying a brand new TD04. On the other hand, I had to build an adapter flange wich was an effort.
I am pretty sure Janis turbo reached it maximum.
 
Cams on our engines I guess are very similar.
Downpipe is ~63mm IIRC and then it enlarges to ~70mm after elastic piece.
I have flat top surface of the pistons, that as @fiatfactory told results in a poorer squish.
If this table from wiki is correct then cam has 9.2mm lift
7E0BF49D-F778-4A3B-B7FA-DCAD15AA7984.png

83DCC38B-91B7-4FB6-95E1-DF020F45F814.jpeg
 
At my understanding low rpm torque is more likely because that small IHI spools up instantly.
These are calculated curves of 1.6 stock NA
5BC73AE5-6055-498A-8FA8-201D53DE26F8.png
 
mkmini said:
At my understanding low rpm torque is more likely because that small IHI spools up instantly.
Click to expand...
I agree. That's the reason the factory turbo engines use a small turbo. Good torque, especially at lower RPM's, make for a good driving car on the streets.
 
You must log in or register to reply here.
Back
Top