I guess 320 RWHP ;-) Is this the stock engine or the 2 liter stroked version?

 

How did your test go @jamiealfa?
Any clues yet

 

How did your test go @jamiealfa?
Any clues yet

Hold your horses we have booked the rollers until next Friday so there is much work to do.

 

This another 2.0 litre but with some new trick bits on it, so we are expecting power into the low 400's. We suspect that we are going to have to uprate the fuel pump and change the injectors to get to where we want to be though.

 

2L should be very niceeeee

 

bump!

 

Well after two weeks work this is where we are with the 2.0 litre engine, 404 bhp not to shabby, I was expecting slightly more at around 425 bhp and with some other changes that is easily possible. We came across a number of issues on the way but we have worked them out, some of which I suspect we can incorporate in our lower power modifications to help give a little more pep to them. The engine idles nicely and will pass standard emission tests.

 

Well after two weeks work this is where we are with the 2.0 litre engine, 404 bhp not to shabby, I was expecting slightly more at around 425 bhp and with some other changes that is easily possible. We came across a number of issues on the way but we have worked them out, some of which I suspect we can incorporate in our lower power modifications to help give a little more pep to them. The engine idles nicely and will pass standard emission tests.


View attachment 103758

Impressive results thus far. I am wondering how power will hold up as turbo inlet temperature gets much hotter. A larger intercooler of course helps....but perhaps a water cooled intercooler will make a big difference. And how about water injection?

 

OMG . Christmas comes early this year .
Is this with standard, hybrid or twin scroll turbo?
You make me yearning to buy a spider and mod my coupe to a track only toy

 

Same power at 3000rpm as we normally have at max, that midrange must be amazing.

What’s the reason for the quite steep torque drop from 4500rpm? Head? Turbo? Cam? Exhaust? All of the above?

 

@AAaF Can anyone really hold onto torque when building up HP like that? The cam can't do everything, and all the variable stuff has a limited range. The 2.0 is limited in mass, so something has to drop.

(Now I await the tuning experts to crush my comments above!)

 

@AAaF Can anyone really hold onto torque when building up HP like that? The cam can't do everything, and all the variable stuff has a limited range. The 2.0 is limited in mass, so something has to drop.

(Now I await the tuning experts to crush my comments above!)

It is fully possible to have relative flat torque above turbo threshold, there are numerous examples of that, here is for example BMW 2 litre engine before and after tuning, no physical changes:

You can see that max torque is not a lot higher, but it keeps flatter for longer, thereby increasing power massively from 184 to 270hp(flywheel). Should be a lot more fun to drive.

Very basically you need:
Fill cylinders with as much and as cold air mass as possible.
Evacuate burnt gases as efficient as possible.
Both these are made more difficult with increasing RPM. More air is going through IC, and temp increase. If cold side of turbo is sqeezed regarding flow, it becomes less efficient, and energy is turned into heat instead of pressurizing air.
Hotside of turbo act as a restriction for exhaust gases, increasing with rpm. All this reduces how much air you get into cylinders(higher temp is lower air density), and increases chance of detonation, because of heat, and you have to back off ignition timing, and loosing power in because both of less air and less ignition timing. And probably more I'm not aware of.

I do not know much about cam and head, except they obviously need to big enough.

 

^^Need the bore and stroke of both to compare. That's the first thing to compare. 2.0 vs 2.0 is not enough.

 

It was just an example of a torque curve that is more linear, stroke volume was just a coincidence. There are more linear than this as well, but together with the low turbo threshold it's quite impressive though.

Bore and stroke is secondary to what I mention, its a way of obtaining just that. More bore equals more area for valves, increasing flow capacity but you loose torque since stroke goes down at a given volume. But max RPM goes up, as piston velocity goes down, so if you gain more in RPM than you loose in torque, you have more maximum power.

The drop we experience at our car is a result of a system not optimized for high RPM; turbo, exhaust, IC, head etc., etc., but a brutal midrange is entertaining in daily use. And not that top end is very bad. So a good compromise, but I'd gladly sacrifice some turbo threshold and midrange torque to have a flatter torque curve.

We know that turbo compressor can deliver around 0.235g/s, this translates to just above 300hp with normal BSFC, above this and you are turning the energy into heat at compressor side. So its obvious that AW have another tubo than OEM. But what else? Only AW knows I guess. I was just curious if they had seen bottlenecks elsewhere since torque is dropping even faster than at the 280-290hp system, discoveries that may be transferable to the 1.75l system.

 

Above 4000 RPM, what is torque doing for you?

This curve is typical and this whole thread is why I stay out of these types of threads.

90% of where torque comes from isn't present in the design, stroke, mass, etc.(of these 2.0's or other little 4 bangers). The entirety of many of the 2.0 designs are to move torque down low and penalize (more or less) any attempts to get it to stay flat or peak higher. The entire approach to modern 2.0's (when the engineer brings proverbial paper to pen) is to fight exactly what you are looking for.

Peace. Let's file this under "I'm not qualified to have this discussion." Wherein qualified = I don't have time to get into engine builds and their discussions. Life is too short.

Good luck in your endeavours. Ciao Ragazzi.

 

Above 4000 RPM, what is torque doing for you?

This curve is typical and this whole thread is why I stay out of these types of threads.

90% of where torque comes from isn't present in the design, stroke, mass, etc. The entirety of many of the 2.0 designs are to move torque down low and penalize (more or less) any attempts to get it to stay flat or peak higher. The entire approach to modern 2.0's (when the engineer brings proverbial paper to pen) is to fight exactly what you are looking for.

Peace. Let's file this under "I'm not qualified to have this discussion." Wherein qualified = I don't have time to get into engine builds and their discussions. Life is too short.

Good luck in your endeavours. Ciao Ragazzi.

Thanks, I don't fully understand what you are saying.

Torque and rpm is equally important.
HP = Nm x rpm / 7019
No torque, no power. So no torque above 4000 rpm equals no power above 4000rpm, thats no fun. Or if we had flat 400Nm torque to 7019 rpm, we would have a 400Hp car, now that sounds interesting doesn't it?

And for anyone that cares:
Mass does not generate torque when rpm is increasing, but mass create inertia, that allows us to accumulate energy, and can be transformed to torque until the accumulated energy is used, when rpm is decreasing. For example a big flywheel makes it easier to not stall an engine. But as it accumulates energy with increasing rpm, this is power lost on the dyno.

More stroke generates more torque, but at the penalty of piston speed.

Generating a lot of torque at low rpm is to get fuel efficiency in the rpm normally used, you decrease miscellaneous losses. But as mentioned, you need some rpm to get power. Here is an example of how much fuel is consumed pr time, pr generated energy, depending on load and rpm. You can see that it is most efficient at 2200RPM and approx 85% load:

Outside this spot, and your consumption pr time goes up, given that you need the energy.

Consumption map - Wikipedia

en.wikipedia.org

 

Layman here, definitely not qualified to address the engineering, but looking at the graph with the flat torque curve, the peak power is a ridiculous 220HP. Yes, better than stock, but it is hardly pushing the envelope of what some 2.0 litre engines are capable of. It looks more like the dyno of an NA car than a turbo.

I would suggest that this car would (if light enough) take off like a shot but have a top speed somewhere in the useful highway range (depending on gearing and assuming that it has aerodynamic properties more appealing than a sheet of plywood).

Jamie's 2L tuned 4C would take off even faster, and have a higher top speed, all other things being equal, as it has both higher peak torque and peak horsepower. And neither peak is all that steep. There is certainly a lot of usable powerband in the tune. I think it would be much more "fun" to drive.

 

As I said, I was just curious if they had seen bottlenecks that could be transferred to a more normal setup.

Yes, AW will be a lot faster in every way, the 270fwhp was just to show that a more linear torque is possible. ESS had a kit giving 450hp of the same 2l engine, but its gone, so I guess that was pushing a 184hp engine too far

Here is another example to be sure its not possible to compare to our engine in any way, a 1.35l rotary/Wankel engine, beyond 400hp at 16psi:

Here, the owner has developed (10 years)so that hotside is restricting as little as possible, and intake delivers as cool air without much pressure drop.

 

I do know how to get more power as well...........

 

Fantastic, I think you are sitting on a gold mine if you have a good way of getting transmission and clutch to keep up. Do you have a plan for that? Seems like you have 570-580Nm(?) Edit: It freaking says 631Nm/466lbft in dyno, sorry....

Looks like OEM cannot take even 415Nm when used hard....

 

Numbers look great. What turbo did you use? That’s a lot of boost, was this on pump gas? WI?

 

How difficult would it be to put a ZF automatic transmission in the 4C?
Would it just depend on software, or is a swap more difficult than I think?
Would be able to take massive amount of torque.

 

Probably impossible + it would be heavier --> adding weight on the rear of this car is the worse thing you can do.