M104 Twin Turbo Conversion - What would be required?

[RBYCC]

Aka$h: Could I please clairfy that you are saying with only a split unit, I wouldn't need to delve into piston & conrod modifications, nor gasket modifcations and it would result in more power?
If I have understood the above, would it be beneficial to upgrade pistons, conrods & head gasket in addition to a second unit, or would the cost implications be too great for any further power advantages?

Darren

Darren

Aka$h is correct suggesting the Split Second additional injector controller.
It's low cost, easy hook up +/-12VDC, Speed signal from tach, vacuum line from manifold for the internal MAP sensor and wiring out to the additional injector(s)
Smaller then a cigarette pack and about 225 sterling.
I was probably the first to use this unit on a TurboTechnics install.
Initial suggestion was an Aquamist unit but it controls via potentiometers not software.
Not sure if you have any Split Second stockists in the UK,but available direct from Split Second in the USA.

Before you decide to purchase the TT kit, do a compression and leak down test..
Imperative that you're assured that all cylinders are within factory spec.

If you have a lower mileage engine with solid internals it can easily handle .5 bar boost and just about double your stock power.

The Split Second unit is programmed with a laptop with the car or a dyno or on the road...easy to attain a 11.7 AFR under boost which will preclude any detonation.
I found the TurboTechnics supplied controller to not keep consistent AFR' through the RPM range..

For added power a simple water/meth spray is an inexpensive system to install.

The beauty of the Split Second unit firing an additional injector(s) is that you leave the standard HFM in tact with no change to the factory settings. This allows the engine to pass any emissions testing.

Probably want to run a colder heat range spark plug and even a hotter coil.

Not a true bolt TT kit on but well worth the time and effort...:bannana::bannana:
Finished product with reasonable boost level will be very reliable...
It will probably end up costing the thousands and thousands that you reference...
More power means nothing if you can't get it to the road surface..which means suspension modifications and stickier tires on a larger wheel..

Good luck

Ed A.

P.S.

My M103-12V TT pulled 262HP and 302 torque on a Mustang load dyno at .5 bar boost....baseline pulls were 135HP and 145 torque against a publishe 177HP/188Torque...
Extrapolate from the published USA power numbers 262/135 x 177 = 344HP, 302/145 x 188 = 392 torque.

http://www.youtube.com/watch?v=1kCPCpL1_9k&feature=plcp

 

[mercboiuk]

Thanks for the advice, Ed.

I hadn't thought of a compression & leak test - I will ask my Indy if they can perform one while they currently have the car.
I now have a better understanding of this extra unit, so thank you for that, too!
Thanks for the performance figures - they are very impressive

Ref: The thousands and thousands to sort everything else.
My wheel & tyre combination is good at present, but I shall be going with some tastey Michelins Pilot Sports at the next change (probably before I get round to sorting a Turbo conversion). The tyres are amazing after I switched to them for my Audi!
My sportline steering box and anti roll bar have been upgraded, and suspension and brakes will be done later this year. I fully intend on having the rest of the car fully sorted before I go ahead an add more power.
I was once told that you should first learn to drive your standard car, then sort the handling and stopping before adding any power. Sound advice I believe.

Darren

 

[RBYCC]

Thanks for the advice, Ed.

I hadn't thought of a compression & leak test - I will ask my Indy if they can perform one while they currently have the car.

I now have a better understanding of this extra unit, so thank you for that, too!

Thanks for the performance figures - they are very impressive

Darren

Darren

Not many shops can do it but you want to do a pre and post install "smoke test"...
Smoke is injected into the engine under pressure and it will find any leak that you may have...
Vacuum/boost leaks are difficult to locate without a smoke test.

Cheers

Ed A.

 

[janner]

I machined the pistons on mine but if you can get modified conrods, that's the way to go.
I ruled out a thicker headgasket because I was worried it would throw out the cam timing.
I don't think you should run turbos on the m104 engine without reducing the compression ratio.
One other thing to consider is the exhaust. The TT kit comes with a stainless exhaust. You really need to replace the standard cats with higher flowing stainless ones and get them welded up to fit. It won't pass an MOT without cats (mine needs a good run to get them hot before it passes).

Mine produced 280bhp and 350ft/lbs on 0.5 bar. I don't know what it was before.

 

[NISFAN]

IMO you would need to re-bore the engine. With 118k miles on it there will be wear, and the additional cyclinder pressures that Turbo's give will mean you will have high leakage past the pistons (technically called blow-by), which will cause serious issues. (Blowing the dipstick out, blowing oil out the breathers, etc.)

I would source some forged pistons, 0.5mm oversize from the likes of JE, WISECO, etc. If they don't make them already, they will make you a set for sensible-ish money. You can then specify the correct compression ratio, without resorting to crude methods like fitting thic head gaskets.

On the fuelling front, the extra injector is a very poor method of giving the extra fuel.....don't do it.

 

[NISFAN]

Techincally the only reason they reduce compression when using the kit is to avoid detonation. This is caused by the air\fuel ratio not being within spec. Using a 3d map such as a split second deivce, it is possible to keep the engine correctly fueled which would mean you dont need to lower the compression and the end result would be more power and more torque.

The possibilities are endless.....

This statement is wrong

 

[mercboiuk]

Hello Janner.

Thank you for experienced input

After youve gone down the route of pistons, may I please ask why would recommend modified conrods?

Who there be any benefit to using the 3 menthods mentioned in combination? So have a modified head gasket, along with custom pistons and conrods. Or is this just an unecessarily expensive venture?

I hadn't thought of the exhaust. Would it be a case of having a free-flow cats to reduce the back pressure (I have a local Powerflow agent who I know can supply them), or would it have certain specifications, being a fine tuned exhaust system for the turbos?

Thank you for your power figures, too

Darren

 

[mercboiuk]

Hello Nisfan.

Thanks for replying with this extra information.
Would the wear of which you speak be detected by RYBCC's aforementioned smoke test, or is that for something completely different?

Once again my naivity on the subject has come into play here. You speak of having an 0.5mm over-sized bore. This is to drop the compression, yes?

You sound like you are against a head gasket modification and an extra injector (which I believe the original kit demands, albeit with crude electrics).
As I'm not sure, could you go in to your thoughts a little more, so I can fully understand the pros and cons?

All input is very welcome, so I appreciate all the information on offer

Darren

 

[NISFAN]

No the increase in bore is purely to machine out any wear marks in the cylinder. At 118k miles the bore will have wear ridges and will be slightly oval in shape. A re-bore will correct this.

The new piston tops will be shaped to increase in piston volume, and therefore give a lower compression ratio. Stock conrods.

Using a thick head gasket is a crude way to increase this volume, but totally screws up the well engineered 'squish' built into a modern engine.

Turbo's of course feed the engine with higher density air. The standard fuelling system was never designed to flow the additional fuel required for the additional air. So a crude way to correct this is to dump the extra fuel required upstream, and hope that it mixes well enough to give a homogenous fuel air mix in every cylinder. In practice this doesn't work out. Some cylinders will be richer than others.

This extra injector nonsense is an 1980's turbo charge trick, and doesn't belong in 2012.

Ideally you would either be able to re-map the standard ECU, or fit an aftermarket one, together with correctly sized (larged capacity) injectors.

 

[bolide]

You need to sit down with an engine builder to map out your requirements and a path of how to achieve this. Whether than will come in within your budget will be a consideration

The stock engine runs quite a high CR and the traditional approach to aftermarket turbocharging involved reducing the CR. Methods to do that include a thicker CHG (fairly traditional now), machined pistons (obvious & old-school and I imagine it requires careful measurement & thought to deliver a consistent result) or shortened conrods (relatively easy if you have the appropriate measurements on hand and this will let you use a standard CHG & pistons)

It wouldn't surprise me if it were possible to run the standard CR with a turbo setup nowadays, due to better management & boost control, but it would limit your maximum torque & power output

The standard engine has a CPS, variable valve timing, twin knock sensors, MAF, intake air temp sensor, water temp sensor and a large single throttle body so I would think all the elements are there for a successful 3D management retrofit. To manage it all completely, and also control boost, I'd think you'd need a good management system and a fair amount of mapping time

Nick Froome

 

[NISFAN]

Please note that the piston idea I mentioned is to be carried out on new forged pistons, NOT MACHINING stock CAST pistons. As mentioned, there are a number of Piston manufacturers that will do this for you.

As for choice between shortening con rod, and fitting thicker head gasket....both have the same effect of ruining the squish.....so as a headgaset would be cheaper go for that.

I personally wouldn't run a turbo on stock cast pistons, so piston is the only way forward in my mind.

 

[janner]

After youve gone down the route of pistons, may I please ask why would recommend modified conrods?

Modified conrods is the best budget way of lowering the compression. I couldn't find anyone to do it so I had the pistons skimmed instead. I did look at custom pistons and rods but it all starts to get silly money. If Ian now has someone who can modify the rods then do that.

I don't agree that the engine needs a rebore at 118k if it's been properly serviced. Mine had done 70k and was like new inside (it's not a Nissan engine )

Agree that the proper way to do the fuelling is larger injectors and a remap but the 1990s Mercedes ECU is not so easy to map (I think) and an extra injector is included in the kit and works well enough with a Splitsecond at 0.5bar.

I went for new cats because the engine will be flowing more than the standard cats were designed for.

It's not a simple bolt-on kit for sure.

 

[mattc]

Darren, you will struggle to do this for less than 4k just bolting on to your existing engine. I asked for a rebuilt engine from the bottom up so you can understand it was more than that.

Be careful what you do because you may end up chasing ever increasing horsepower for silly money. A c3.6 engine with better fuel management might give similar results.

Adrian, was 0.5 bar the standard setup; I thought it was 0.7?

Matt

 

[janner]

0.5bar = 7psi

I take it you've seen Roman's videos? Slightly crazy guy but he got 650bhp, 780nm from a stock M103 engine (it's a lower compression motor than the M104)

[YOUTUBE]JoV8ePXxFSE[/YOUTUBE]

 

[NISFAN]

....I don't agree that the engine needs a rebore at 118k if it's been properly serviced. Mine had done 70k and was like new inside (it's not a Nissan engine )

Agree that the proper way to do the fuelling is larger injectors and a remap but the 1990s Mercedes ECU is not so easy to map (I think) and an extra injector is included in the kit and works well enough with a Splitsecond at 0.5bar.

I went for new cats because the engine will be flowing more than the standard cats were designed for.

It's not a simple bolt-on kit for sure.

Ha ha very funny .....of course if it was a Nissan they would have got the correct amount of horsepower out of it already, so a turbo would not be required. (ducks for cover)

If 0.5 bar is all you are looking at running, you could chance it by leaving the engine stock, and running hi octane fuel (V power or Tesco 100), but going through all that hassle to run 0.5 boost is a waste of time. IMO

 

[d w124]

Ha ha very funny .....of course if it was a Nissan they would have got the correct amount of horsepower out of it already, so a turbo would not be required. (ducks for cover)

How many Nissan`s have you seen with half milion miles I`ve seen a few mercedes

 

[RBYCC]

On the fuelling front, the extra injector is a very poor method of giving the extra fuel.....don't do it.

I beg to differ..your comment flies in the face of many proven installations some twenty years old !!!

TurboTechnics engineered the kit as if it was a factory option..
The location of the additional injector(s) is key to proper fuel distribution.

If it was a poor method then you would not produce the reliable power that the TT install affords..

"Reliable' because there are still many original Hughes installs on your roads...

 

[RBYCC]

I hadn't thought of the exhaust. Would it be a case of having a free-flow cats to reduce the back pressure (I have a local Powerflow agent who I know can supply them), or would it have certain specifications, being a fine tuned exhaust system for the turbos?

Darren

Use the Magnaflow spun metal cat, rather inexpensive and a knockoff of the Random Technology design....

No tuning necessary in a turbo exhaust as the boost pushes the exhaust out and doesn't depend on scavenging like a NA motor...

Free flow is the secret to power...

 

[jaymanek]

"Reliable' because there are still many original Hughes installs on your roads...

Many of the original ones have lasted well, the ones fitted afterwards have not!

I think a lot of it is "engineers" thinking they can better the Hughes technology... another major part of it is starting with engines, fuel systems etc that are 100-150K miles worn.

I know a guy who bought his brand new from Hughes, has over 200K miles now and all he has done is have the turbo's refurbished recently as they got a bit noisy... every other part of it is totally original.

 

[NISFAN]

How many Nissan`s have you seen with half milion miles I`ve seen a few mercedes

Quite a few around, I don't particularly enjoy seeing ANY car with half a million miles on them. They stink