Engine Build Ideas. Please Discuss

[ksminiman]

I did not want to hijack Punk_Mini's thread so I started this one to voice and discuss what I would like to do for an engine build. Please feel free to make suggestions. I want to try something completely new.

The reason I would change the charger is for a roots type. Far more efficient at producing boost at much lower temperatures and less parasitic draw. The biggest reason is for less draw. I am looking to build the ultimate in efficiency with great power as a perk. There are 2 major ways to make power.

1. (most common) Turn up the wick. More fuel, bigger fire.
2. (new concept) Greater efficiency. Burn more of what I already have while using less to do it.

A perfect example of this is the new MINI engines vs. the Tritec engines.
One uses a turbo with very little parasitic loss while the other uses a roots type supercharger, about the most draw you can get.
One uses direct injection to ensure that more of the fuel that is injected is burned rather than sent out of the tailpipe, while the other uses port fuel injection that relies on the heat form the previous combustion cycle to atomize the fuel as it goes into the cylinder.
These are the main differences that lead up to my point. The new Peugeot engine makes a little more power than the Tritec while getting considerably better fuel economy. If it weren't for the Peugeot's fatal flaw, I would be figuring out how to simply put one in an R53.

Or I could simply make my own. I want to completely redesign the Tritec head to flow more efficiently and possibly make it direct injection. If not direct injection, I want to make the existing system more efficient, however I can.

[Minidave]

No matter which way you go, it sounds expensive. Why not just buy a newer car with the newer engine design already in it?

[ksminiman]

I really would like to see if I can come up with a better design. I would really like to take a head and fill in the intake passages to drill and shape my own and calculate the optimum flow rate. I would really like to just outright design my own cylinder head. That I doubt I will have money for that though. I really want to study how heat dissipates across the metal to create the most fuel efficient and powerful cylinder head I can imagine.

Sounds wild I know. Probably lots of money wasted but I might come up with something good who knows.

My inspiration actually came from my experience this summer at Ford.

[Punk_Mini]

For the R53 platform there really is no need to reinvent the wheel. You just have to ask what you want your goals to be in power, induction, driveability, Budget etc.

WHPower = 250, 300, 350, 400, 450, 500, 550, 600, 650

Induction = Factory Roots Eaton M45, Roots Eaton M62, Rotrex, turbocharger

Driveablity = Roots Linear power/torque curve, Rotrex Semi Linear power/torque curve, Turbochargers Kick in the pants power/torque curve

Budget
*210-220whp = stock bottom-end with pulley, cai, GP intercooler, head, cam, header, exhaust, flywheel, clutch, LSD, tune - $10k
*235-250whp = Fully Built on factory Roots M45 - $10-12k
*250-650whp = Mandatory Fully Built - Turbo-only - How deep are your pockets?

*WHP range based on ABF Performances Mustang dyno

[Minidave]

I'm with Punk Mini here, everything I've read indicates that there are only marginal improvements available in flow over the stock head design, and enough other folks are already building replacement heads that I also don't see the point in starting from scratch other than an expensive learning experience.

However, I'm with you on the idea of a different type supercharger, and I also think there are impressive gains available in a better intercooler design. There's the real challenge IMHO, packaging that under the stock hood - there's not much real estate available in there!

I think I'd look to the new supercharger/intercooler design used on the Vette and Cadillac CTS-V for inspiration.......

[Punk_Mini]

There is a R53 over in the UK that is using a lysholm (sp?) 1200rx Supercharger that is making 252whp. Its making only ~10whp more whp then me which is using a mustang dyno on both.

Hubie has found that for the factory SC the limit is 240whp - 8.3:1 (factory) compression ratio and 243-250whp-9.3:1compression ratio

[ksminiman]

I have thought about building a turbo manifold and putting a small twin scroll ball bearing turbo on that will make about 15-17lbs of boost efficiently. With the parasitic loss lessened, I should gain some good power and efficiency.

I want to find a way to lessen the amount of fuel required upon normal acceleration to increase in town mileage. I notice that during even light acceleration at any time, the instant fuel economy reading tends to drop to 10-15. If I lighten up much more I will not be moving anymore.

I do not know, but theorize that the extra fuel that is dumped into the intake on the MCS has something to do with the IATs and emission standards due to combustion temperatures.

I would like to be able to see what the effects of different IATs have on combustion temperatures and combustion efficiency. I'm sure if the combustion temperatures can be lowered, less fuel will be needed for cooling. The problem with that is that the fuel charge will be harder to light. I do not know how much that will effect performance but I know the variable is there.

Another thing that will help is having a low torque band. If the maximum torque can be produced as low as the Peugeot engine, less throttle will be needed to accelerate the vehicle hopefully increasing efficiency.

I am really trying to focus on efficiency because power can easily be made with efficiency. The more complete the burn, the greater the power. That is my goal with this. Honestly I want to learn more than anything. If I create something that works, even better!

I appreciate all the input, please keep it coming. I am not an engineer...yet. I am looking at getting an engineering degree once I complete my current one.

[Punk_Mini]

With my car I get 30-40mpg on flat, wind free, straight highway, 20-30 on hilly, breezy, curved highway and in the city I get anywhere between 10-25mpg.

For a forced induction car like the R53 with indirect injection you want more fuel the more throttle and RPM's you run because since your shoving more air the fuel has to just as much or great to prevent running lean or predetenation its not ment for IAT cooling because even the fuel is hot going into the motor. Naturally aspirated motors run leaner than forced induction motors which run rich.

A lesson in IAT's now whatever the ambient temp is at the time the rule of thumb for best real world performance is 10-40* above that. So if its 110*F outside and your running hard you will see your intake temps go up 40+*F above that which is normal. When I was driving home from LA when I got my car back going through the desert with 115* ambient my IAT's were around 160-190*F with cruise on. The key to efficient intercooler system is recovery. So you are thinking the bigger the IC the better WRONG. For the R53 still on supercharger the GP intercooler is the best in every possible way.

For your goal of going turbo-only the Dr. has been building MINI's including mine and has been developing turbo-only setups for the R53 since 2002. He has worked in cooperation with MIT on the design of his intake manifold for the higher spec turbo-only kits. So if your going to do it right then get into contact with Hubie Fuh tell him your goals and what your budget can handle. He will compose a masterpiece that will put you into shock and awe every time you go and drive the vehicle.

[LiLReD1]

For a forced induction car like the R53 with indirect injection you want more fuel the more throttle and RPM's you run because since your shoving more air the fuel has to just as much or great to prevent running lean or predetenation its not ment for IAT cooling because even the fuel is hot going into the motor. Naturally aspirated motors run leaner than forced induction motors which run rich.

Listen to this, cause this is key. A turbo'ed car by nature when tuned correctly is going to run more rich to prevent spikes in boost to consequently blow your motor. You tune a turbo'ed car lean like an N/A car, you're asking for trouble.

A richer running car, is also a cooler running car, hence, more gas. The efficiency isn't just the turbo in the R56/55/57 cars, direct injection also plays a big part in a more proper and effective/efficient tune.

Heat is always the enemy, it's energy disipating away from your motor... so if this is all yer focusing on, try a more efficient radiator like a fluidyne.

[ksminiman]

Punk, may I ask what the new engine is running at for fuel ratio? I have done some tuning on N/A cars and would be curious just how much different it is.

As you were saying with the IATs, I figured the IATs in the MINI were high due to the roots type supercharger. That is part of the reason I would like to change it out. While the roots type makes awesome low end power, it also produces the most heat of the 3 types. The screw type seems to be the most ideal for the MINI application. Great low mid to high range power with little parasitic draw. If the IATs can be brought down to around ambient air temps, I should think fuel ratios should be able to be leaned a little. I would like to figure out a way to make the combustion more consistent to improve AFRs.

[Punk_Mini]

On any forced induction motor not just mine but any you want the AFR at idle stoich and 11.5-11:1 mid throttle to WOT.

[ksminiman]

Punk, that is not far off of N/A cars running safe. Typically I have shot for 12.2:1 as the magic number for N/A. I would like to be able to hit 12:1 on a boosted car. I do know that at cruise, AFRs can safely get into the 30:1 range with direct injection. I have found even as high as 60:1 on the better systems. I believe it is GMs 2.0L ecotech CDI engine that reaches those crazy fuel ratios. I dont see why any other engine shouldnt be able to run those ratios if designed properly. I would like to see if a higher pressure injection system can be utilized on the tritec engines to get better atomization of the fuel. (or just figure on a way to make the thing CDI. The pump is the most challenging task I think)

As long as a vehicle is at a steady cruise, there shouldnt be any reason why it cant be run at a ridiculous lean mix. The old EEC-IV had the lean cruise mode. pretty awesome strategy.

[Punk_Mini]

Here is an example of TUNE with 15%/exhaust R53 Automatic
There are 3 pairs of lines the two that climb are WHP/WTQ the one that goes down as it goes to the right that is the AFR. So you see from the time sampling starts to the end which is redline the AFR richens up thats what you want in a properly tuned fueling map.


Here is an example of a bone stock R55 Clubman TUNE ONLY
Same deal on 3 pairs of lines as above. The AFR has big spikes which is caused by (pardon the language) little pain in the ass ECU of the R56/R55 motor. Those spikes are caused by Super Knock they are points in which the ECU pulls spark and fuel to any one of the cylinders causing a dry lean. Then you see the other AFR line it is so smooth and consistent that is a properly tuned fueling map on the ECU. If you look on that sheet you will see at the bottom the

RICH Pre-tune 10.8 / Post-tune 11.4
LEAN Pre-tune 14.7 / Post-tune 14.8
AVG Pre-tune 13.5 / Post-tune 12.5

[LiLReD1]

If you run a 30:1 afr at full throttle, you will blow your motor. All motors are different in where there sweet spot in the afr is, but generally speaking, you could run a boosted vehicle at 12.5-13.0 like an N/A car, but then you're leaving no room for error when it comes to ALL the other parameters when tuning a vehicle, including weather itself. A car tuned in Florida won't be tuned with the same map as one in Colorado.

S/C cars can generally run "leaner" than a turbo cause it's hard to overboost an S/C being mechanically driven, unless yer S/C is boosting a lot more than what yer engine can hangle to begin with. Turbo's, you rely strictly on a wastegate. That's how a motor blows on nitrous, not because it's rich with fuel, it's because it leans it out to much.

[Minidave]

The more variables you have, the harder it must be to make effective changes like this...and these engines have a LOT of variables.

Like Punk alludes, the R55/R56 is a different kettle of fish. I watch some of the tune parameters on my new Garmin, and the timing for example on these engines is no longer linear - modified by vacuum - like it used to be; the timing is all over the place depending on load, rpm, boost etc. It's crazy watching it bounce around the way it does, and that's only one parameter, you also have the valves themselves being advanced and retarded, and next year it's going to get even more complicated and complex when they go to variable timing on both intake and exhaust....

It's an ambitious project you're trying here ksminiman, I wish you luck. Maybe you could hire on with one of the MINI shops that does tuning and learn some more basics from them, as it applies directly to these engines?

[LiLReD1]

It's an ambitious project you're trying here ksminiman, I wish you luck. Maybe you could hire on with one of the MINI shops that does tuning and learn some more basics from them, as it applies directly to these engines?

And the only people I recommend, as well as Punk would, who is on the forefront with tuning R53's with several pre-req's and education to back them up is Mynes.

[Punk_Mini]

Very true Dave and Tim, For someone like Jay Bowman (Mynes Tuning) who wrote his own tuning program by reverse engineering the ECU practically by himself for the R53 platform so he knows exactly whats going on down to the hexadecimal and can make changes that can really whip things into shape for a reliable, very driveable, efficient machine. Now for the R56 platform Mynes uses Dimsport for tuning currently and Jay's tuning is impeccable.

[LiLReD1]

Don't they have a stand alone unit for the R53's now that they made Alex?

[Punk_Mini]

Yeah its still in the final stages of development but as its only Jay and one other guy working all the while working with MINIusa/ABF Performance on the Redline Time Attack series racing program, ABF Performance Road Tour Tuning, Tuning days, MINI Takes the States they really have a table full of plates that are stacked with stuff on them.

[LiLReD1]

Looks like you needa put in an application then Alex! lol

[ksminiman]

Punk, thank you for the explanation. I guess the tuning that I am looking at would be for cruise. I understand having the buffer for WOT however I would like to see a strategy similar the the old "lean cruise" strategy used on the old Ford EEC-IV programming specifically for cruising. I would also like to see a highly monitored lean acceleration. Mainly for protection but under a certain throttle percent when a heavy load is not applied. I hope that makes sense. It would require a lot of testing to develope a strategy like what I have in mind but could be very beneficial if figured out. The goal is simple, the process is not.

If you are not aware of the Lean Cruise strategy, I would search online to find the explanation of it. It is quite a clever little bit of programming.