Supercharged Ew10 Questions

[dudaionescu 2]

Hi all,

Ran over this page doing some research on next development on EW10 internals.

This is what happens when a crazy client meets a crazy automotive engineer, we've successfully married a EW10J4 engine with an Eaton M62 roots supercharger for a street sleeper 206 GTI.

Engine is fine running with DP engineering decompression plate and 2:1 engine pulley (that's the max we could get as ancillary pulley size, about 18.5cm in diameter) which yields about 0.8 bar in the custom intake. Dyno results and engine pictures attached.

We had to use bigger injectors (350cc@3bar, fuel rail pressure is 3.5 bar). Fuel pump had to be upgraded to a 2.0 TFSI one, stock one is not enough. We also installed a water meth spray for safety but weirdly it cuts out 20Nm when on.

The result is a quite funny frying pan that is enjoyable to drive and overtaking is ecstatic.

Since I was not happy with the power delivery + we managed to f**k up an engine using sh1te cylinder rings (NEVER USE TARABUSI !!!!), put another EW engine with stock compression and used the standard pulley. So far it goes ok for street use with 0.5 bar boost, ECR should be insanely the same (about 16.something:1) and power should be the same, only that it feels quicker since partial ECR goes up a bit faster. I am planning to install the 2:1 pulley on stock compression (0.8 bar with 10.8:1 compression should be pretty risky, isn't it?).

I was not happy with decompression plate since low rev performance was crappy, fuel consumption quite high, lots of soot/carbon buildup in the combustion chamber, a Lancer EVO 10 catalyst was practically burned down by unburnt fuel). Decompression plate is good only for turbo AND track racing I assume but not for street use.

I am looking for next improvements for this engine and would kindly ask for your oppinion. I have the opportunity to get my hands on a XU10J2TE (RGX) or on a EW10D engine with the folowing options:

- give up current engine, install XU10 turbo engine, upgrade for more power. Probably going for higher than 200HP (which I currently have) would also be a challenge since the ECU and MAP have limitations.

- give up current engine, move the supercharger to the EW10D engine and since it's direct injection 300HP+ would be easy to obtain (e.g. 2.0 TFSI that goes stock to 400HP). MUX component shut-off would be a challenge since SIRIUS81 ECU is MUX and my bolt bucket is non-MUX

- combine XU internals with EW block - is it possible ? Are RGX pistons a choice ? Are they forged ? Can I adapt them to the EW10 block and crank with just a minor rebore/hone? Are the rod big ends friendly with my crank ?

- use just EW10D hollow pistons for higher static compression but possibly knock-free operation (?) - see chapter 5-4 here: http://www.qclt.com/html/%E6%A0%87%E8%87%B4206_406/406D9/INFO/gb/a--t0gk3.htm

- give up everything, leave it as it is.

What say you?

Edited January 2, 2013 by dudaionescu

[Vili 17]

I would probably drop the compression down to 10:1 or even 9,5:1 by skimming down the pistons and maybe slightly thicker headgasket. Fit an intercooler and longer inlet manifold and after that fit the pulley to increase the boost. I believe you should be able to reach 300 hp quite easily.

[Vili 17]

I do not know much about superchargers but would it be better if you fitted the throttle after the charger? I can't tell because I don't have hands on experience but the stock throttle might prove to be too small when fitted before the charger.

Edited January 2, 2013 by Vili

[welshpug 1,621]

I doubt it will be too small, what size is it? stock gti6 t/b will flow 400+

[dcc 855]

Isnt matt getting close to 340 on standard engine?

[dudaionescu 2]

I am a bit afraid to skim pistons for mass and BMEP resistance concerns. Thicker head gasket would lead me to the same point where I was with the decompression plate: poor performance and horrible fuel consumption below 4000rpm. Root cause are knocks, decompression is the easiest but worst workaround. Since I am not using racing fuel, I am leaning towards direct injection but I have reserves about reliability of ew10d. The water meth spray should theoretically allow more aggresive timing advance...

If you are talking here about cfm, I dont think I can get more than 350 from the m62. Since bloody cost cutting has put a TPS instead of a MAF I cannot tell...

Tb is stock 50mm one. Pressure buildup is quite quick. I think longer rams do not help since this is no longer a nasp engine where you need variable intake manifold for low rev high speed air... am I right?

Intercooler is excellent idea, space is a problem.... However IAT is above 100C hence I am limited by knocks

Please DO criticize my setup, any good constructive idea is welcome!

Edited January 2, 2013 by dudaionescu

[welshpug 1,621]

That sounds more like poor mapping than anything else.

 

EW10D isn't very well known, and must be a reason why it was only used for 2-3 years and EW is still IDI not DI.

[Matt180 31]

374bhp currently @ 0.8bar. Cant really compare as im using a rotrex s/c, far more efficient than a eaton.

Edited January 2, 2013 by Matt180

[dudaionescu 2]

Mapping is done by piggyback.

 

Matt, what is the actual air volume that you are feeding the engine and also which intake temp do you have? Also, which compression, which internals and at which rpm? Dyno graph is also at 0.8 bar but very hot air and far from 300hp what would the problem be?

Indeed centrifugal chargers are a different story but I'd like to stick to roots charger for low rev violence and quick takeovers. Maybe will go to a twin screw if budget allows.

However, there is a huge difference between the two setups and I think that not charger efficiency difference is causing it but rather something wrong in my setup. Any idea is welcome

Edited January 2, 2013 by dudaionescu

[Matt180 31]

I dont know the specifics but it makes 374 @ 7990 rpm. I could fit a smaller pulley and bring the power in much lower but the way it makes power works well on track. Its on stock internals and the C/R on these engine is fairly high for boost at 11.1. Inlet temps were in the 30' s when mapped but are much lower now. I have not recorded any inlet temps but after 15-20 laps the i/c, boost pipes and inlet are still cool. I run a intercooler spray aswell.

 

 

I'd go for a standalone ecu before looking at anything else.

Edited January 2, 2013 by Matt180

[dudaionescu 2]

For race application where you drive mostly WOT, yes, I wouldn't have gone elsehow...

Street racing is a bit different, with lots of partial load while braking/accelerating.

I'm also thinking about standalone but I will lose most of the dash functions and not happy with it... also specialists are not too good in my country for that.

So you say that mapping should be the problem ? Or shall I start intercooling it before?

Happy to hear that you're using stock internals, I am now seriously thinking about going to 0.8 bar.

Got it now, your s/c delivers 0.37kgs of air per second which is fairly about 640cfm, almost 3 times my charger delivers, hence the difference

Will probably go turbo if I manage to find a poor lad that adapted the XU10J2TE engine to the 206...

Edited January 2, 2013 by dudaionescu

[allanallen 528 2 Cars]

I'd say intercooling and a proper mappable ecu/mapping is a must, 300bhp should be easily and safely achievable when sorted.

From a performance and mapping perspective You may need to look at moving the throttle body downstream of the charger. You could leave the one before the charger as well if noise was an issue.

[dudaionescu 2]

Assuming that my IAT is 120C (which I doubt) and lowering it to 40C by intercooling (which is a challenge during summer time), this would bring me an upgrade of around 20% more air density which would translate in theoretically 40HP more. The s/c parasitic power is about 25 HP and with a bit of ecu help I would definitely look towards the 300. Standalone is quite expensive I would say...

Thanks, keep'em coming.

 

 

 

THROTTLE PLACEMENT
When implementing a Roots supercharger, you must install a bypass valve and relocate the throttle body ahead of the supercharger’s inlet port. If you don’t move the throttle body, the supercharger will build up pressure between the supercharger and the throttle whenever your foot is off the accelerator, such as when you’re idling, decelerating, or changing gears. When the pressure between the supercharger and the closed throttle exceeds the boost pressure being supplied by the supercharger, the air will be forced back through the supercharger. However, air can only move in one direction through a Roots-type supercharger. If the air tries to flow back through the supercharger, the supercharger will cease and will destroy the drive belt. This can also cause the throttle plate to buckle and get jammed in the throttle bore as the pressure will not be released. Of course, moving the throttle body further away from the intake valves will make the engine less responsivto throttle input, but that’s just the cost of running a positive-displacement supercharger.

 

 

Source: http://www.sic-performance.com/2011/06/21/supercharger-basics/

Edited January 2, 2013 by dudaionescu

[allanallen 528 2 Cars]

Assuming that my IAT is 120C (which I doubt) and lowering it to 40C by intercooling (which is a challenge during summer time), this would bring me an upgrade of around 20% more air density which would translate in theoretically 40HP more. The s/c parasitic power is about 25 HP and with a bit of ecu help I would definitely look towards the 300. Standalone is quite expensive I would say...

Thanks, keep'em coming.

 

 

 

Source: http://www.sic-performance.com/2011/06/21/supercharger-basics/

I'm basing what I said on throttle placement on my own experience with the roots charger on my car, aswell as what a lot of Honda/eaton conversions use.

You'd need a blow off valve and I'd recommend leaving the other tb on as well (like the eaton Mazda/miata conversions do).

 

 

[dudaionescu 2]

Thanks for the kind advice. In this respect, would the setup be CAI-airfilter-TB#1-charger-TB#2-intercooler-inlet manifold or CAI-airfilter-TB#1-charger-intercooler-TB#2-inlet manifold ?

Shall I use similar TBs?

Can you please reccomend a street usable stand alone system, that can handle nicely partial loads and knocks and that is used daily in this engine? I am not looking for a racing application... VEMS looks fit for racing, I was told that Megasquirt is for basic setups... maybe a custom map for the MM 4.8P ECU?

Edited January 2, 2013 by dudaionescu

[dudaionescu 2]

It's called 'maintenance and performance upgrades', or that's what my poor English knowledge tells me it may mean. Maybe there is also a specs thread, but this one does not appear like it. Cheers.

Edited January 2, 2013 by dudaionescu

[Vili 17]

I doubt it will be too small, what size is it? stock gti6 t/b will flow 400+

 

Most likely it will flow enough for 400 when fitted after a charger. When fitted before it will flow the same volume but less mass (and power) because of smaller air density.

Edited January 2, 2013 by Vili

[dudaionescu 2]

Air density is bigger before the charger than after it. Therefore the same volume of air will contain a bigger mass before the charger than after. Since the engine burns mass and not volume, it is more efficient to flow cooler air in a given section area than hot one, since mass is bigger and more fuel can be burned stoichiometrically. Of course, if there is an aftercooler before the throttle, situation is different...

Edited January 2, 2013 by dudaionescu

[wracing 19]

Spinning the M62 at 14000rpm produces a fair amount of heat to produce any kind of real performance you must inter cool these.

 

 

Keep the stock compression and lower the charge temps by fitting a intercooler.

 

I assume that with the piggyback management it was unable to change the ignition timing, with 120degree charge temp and standard ignition timing in will knock holes in the pistons.

 

Fit ONE throttle before the supercharger to simplify control you don't need 2 throttles.

 

Fit the vacuum hose between the throttle plate and the supercharger for your brake servo.

 

Dont over analyse the issue you have a working package you just need to refine it.

Edited January 2, 2013 by wracing

[dudaionescu 2]

Thanks!

Brake vacuum is picked from a special outlet on he throttle body. Dont know whether this is fine or not...

Timing advance was modified safely with the piggyback, it's DASTEK UNICHIP.

Edited January 2, 2013 by dudaionescu

[wracing 19]

Fitting the brake servo vacuum take off after the supercharger is a bad idea. What sort of timing curve are you running @ 0.8bar of boost?

 

James

[allanallen 528 2 Cars]

Fitting the brake servo vacuum take off after the supercharger is a bad idea.

 

Not with a non return valve it isn't

 

The OP seems to be struggling with mapping so fitting an intercooler and leaving the the TB before the charger is not making life easy for himself really, hence my suggestion

[Vili 17]

Air density is bigger before the charger than after it. Therefore the same volume of air will contain a bigger mass before the charger than after. Since the engine burns mass and not volume, it is more efficient to flow cooler air in a given section area than hot one, since mass is bigger and more fuel can be burned stoichiometrically. Of course, if there is an aftercooler before the throttle, situation is different...

 

If air density was bigger before the charger than after you would lose power by fitting one. You have a flaw in your thought process. Your only considering the temperature of the air when you should be thinking temperature and pressure.

If your throttle flows 350 cfm at 1 bar absolute and 20 C it will flow 0,2 kg/s (dry air)

when fitted after the charger under the conditions 1,8 bar absolute and 100 C it will flow 0,29 kg/s

if there is an intercooler and the conditions at the throttle are 1,8 bar absolute and 40 C it will flow 0,35 kg/s

[dudaionescu 2]

Vili, thank you for explanations and patience. Since the charger is volumetric, the pressure is a result of the plenum chamber volume after it, so this is why I have taken pressure off the discussion. If I will place the immediately after charger then intake pressure will be the same only at WOT...

Alan, next question that arises into my mind now is 'why?'. Can you kindly tell me where to document myself about the relevance of this tb placement? Is it because the intercooler or does it happy to what I have now?

Edited January 3, 2013 by dudaionescu

[dudaionescu 2]

Later edit: 'happy' = 'have to'. Bloody spell checker