Forced Induction noob questions

[Pooter]

Hey guys, I recently bought a supercharger that was from another Lotus. I am trying to piece together all the bits and pieces I need to get it going on my Elise. I have been blasting TJ at FVMC with tons of questions and I've been researching a ton of stuff just so I can feel a little bit educated about all this supercharger craziness. I still have a few questions though.

1. Is there any difference between the Bosch 440cc "green" injectors and the DeatschWerks 440cc "blue" injectors? Would both work for my application?

2. I have a new Walbro 255 fuel pump that I'll be using... Should I get an aftermarket fuel rail to help with the new fuel demands of a supercharger?... or is that overkill?

I am not trying to make massive power or anything. I just want to be as close to stock as possible. If there are any improvements or odds and ends that I should get, let me know. I'm hoping to have all the parts collected within a month or so.

[lil_lotus]

The stock fuel rail will be alright if you stay under 300HP

[Westrock]

1. Assuming the DeatschWerks injectors are the compatible electrically and physically they should be ok (IMO). Which it looks like they are. Spray pattern may be a little different, but doubt any real world difference.

2. I think most people here get aftermarket rails so they can use a rising rate fuel regulator (and in turn convert to a return line) for systems going into the double digit boost ranges.

[turbophil]

Originally Posted by Pooter

Hey guys, I recently bought a supercharger that was from another Lotus. I am trying to piece together all the bits and pieces I need to get it going on my Elise. I have been blasting TJ at FVMC with tons of questions and I've been researching a ton of stuff just so I can feel a little bit educated about all this supercharger craziness. I still have a few questions though.

1. Is there any difference between the Bosch 440cc "green" injectors and the DeatschWerks 440cc "blue" injectors? Would both work for my application?

2. I have a new Walbro 255 fuel pump that I'll be using... Should I get an aftermarket fuel rail to help with the new fuel demands of a supercharger?... or is that overkill?

I am not trying to make massive power or anything. I just want to be as close to stock as possible. If there are any improvements or odds and ends that I should get, let me know. I'm hoping to have all the parts collected within a month or so.

Latency may be a bit different on the DW injectors. They're Denso units. Quality is fine by comparison. I'd bet latency would be quite similar, which should mean they're safe to run. Just verify your AFRs after the build.

Stock fuel rail is good to atleast 414whp, IME....

You can make a peak of about 270whp with the stock Elise/Exige S pump and 440 injectors. Can make up to about 300whp with a 255 pump and 440 injectors.

What kind of blower kit are you trying to assemble?


-PV

[Pooter]

Originally Posted by turbophil

Latency may be a bit different on the DW injectors. They're Denso units. Quality is fine by comparison. I'd bet latency would be quite similar, which should mean they're safe to run. Just verify your AFRs after the build.

Stock fuel rail is good to atleast 414whp, IME....

You can make a peak of about 270whp with the stock Elise/Exige S pump and 440 injectors. Can make up to about 300whp with a 255 pump and 440 injectors.

What kind of blower kit are you trying to assemble?


-PV

It's just a stock MP45. It was pulled from an SC Elise ('09 I think). I'm not trying to go crazy with power... but I'd like to see 230hp. Is that reasonable to expect with header, decat, arqray single, and a solid tune?

[WhatsADSM]

Yea fuel rail is just a cosmetic thing for the most part.

Stock pump is likely fine... not that it would really hurt to upgrade it. If you track it a surge tank would be a logical solution there.

As for the injectors... DWs are okay. Not as good of an injector as a modern FIC or injector dynamics (i say this and i have 1300cc DWs in my car BTW) but at the size you are talking about it will be more than fine you wouldn't really notice a difference anyways even at low pulsewidths (idle or soft cruise).

As for the power... the M45 is really a small blower way way small for the 2zz. Not sure why lotus used it other than cost I would guess and not trying to canabalize sales of thx Exige. In any case my point is don't expect too much from it. 230whp is probably possible just be sure to pay attention to the pulley. You will want to spin the bugger pretty good to make sure it flows enough. Power on a roots supercharged car is largely governed by the induction at the supercharger side. So yea pulley exhaust injectors good tune.

[Pooter]

Originally Posted by WhatsADSM

Yea fuel rail is just a cosmetic thing for the most part.

Stock pump is likely fine... not that it would really hurt to upgrade it. If you track it a surge tank would be a logical solution there.

As for the injectors... DWs are okay. Not as good of an injector as a modern FIC or injector dynamics (i say this and i have 1300cc DWs in my car BTW) but at the size you are talking about it will be more than fine you wouldn't really notice a difference anyways even at low pulsewidths (idle or soft cruise).

As for the power... the M45 is really a small blower way way small for the 2zz. Not sure why lotus used it other than cost I would guess and not trying to canabalize sales of thx Exige. In any case my point is don't expect too much from it. 230whp is probably possible just be sure to pay attention to the pulley. You will want to spin the bugger pretty good to make sure it flows enough. Power on a roots supercharged car is largely governed by the induction at the supercharger side. So yea pulley exhaust injectors good tune.

Thanks for the info. The only reason I went with this MP45 is because I picked it up for nearly nothing (Literally less than 1/4 the cost of the Katana kit).

I was thinking more like 230bhp... not 230whp. I've done a bit of research and from what I can tell, the pulley size on the MP45 is maxed out as is. I am the furthest thing from a forced induction guru, but if the MP45 spins any faster the charge becomes too hot to be efficient and there is no way to add an intercooler to remedy that issue. Please correct me if I'm wrong... I'm still learning.

[Westrock]

Originally Posted by Pooter

Please correct me if I'm wrong... I'm still learning.

Nope that sums it up pretty much.

[addertooth]

I agree with Westrock, your assumptions are very close. 230 crank HP will be at the limit with the supercharger you have (with good basic bolt ons). With a non intercooled MP62, and good bolt-ons (headers, intake, de-cat and walbro 255) you can see 265 crank HP, with an intercooler around 310ish crank HP.
As light as our cars are, even a 20HP difference is *very* perceptable with our cars (in the sub 350HP range).

[WhatsADSM]

What is the pulley size you have on there now?
Also not sure what the stock 2zz crank pulley size is, so if someone knows please post it. Otherwise I can try to dig it up later.

Sorry I don't have more time to describe this (I gotta run with the family quick). But here is the M45 you have. I plotted this thing with 5psi (stock) as well as 2 other points for *slightly* smaller pulleys (6psi and 7psi respectively). It shows a few things:

1) The M45 in general is too small for the engine. This is not surprise, the M62 is hardly big enough
2) With that said it is being spun to the comfortable edge of what it can. However there should be enough flow there for 240-250bhp.



Sorry gonna have to leave it there, if we need more discussion about it post up and I can solve it later. If someone can post up the stock (effective belt) diameter of the 2zz crank pulley and stock pulley used by lotus that would be helpful.

[WhatsADSM]

OK did a little digging looks like the effective belt diameter of the stock 2zz is roughly 5.1".

Did some other digging and it appears the stock blower pulley is roughly 68mm which was exactly what I was going to suggest. (It IS essentially the black dot on the compressor map). So that means 240-250bhp should be possible.

Injectors, header/exhaust, and a good tune should get you there.

[Pooter]

Originally Posted by WhatsADSM

OK did a little digging looks like the effective belt diameter of the stock 2zz is roughly 5.1".

Did some other digging and it appears the stock blower pulley is roughly 68mm which was exactly what I was going to suggest. (It IS essentially the black dot on the compressor map). So that means 240-250bhp should be possible.

Injectors, header/exhaust, and a good tune should get you there.

Thanks for the info. I am completely happy with 240-250bhp. I've never been into sports cars until I bought my Elise a few years ago. I got into offroading and building crawler rigs that only see about 5mph top speed on the rocks. To be honest, the Elise was plenty fast enough for me in NA form. I'm sure this factory supercharger will take me right to the edge of what I am comfortable with as far as speed/capability. I am the idiot that always pushes the limits of modification with all my fun cars, so it'll be nice to know that I am not sacrificing reliability with this supercharger setup. I don't plan on getting crazy with this Elise until I pick up a first gen NSX for a daily.

[WhatsADSM]

Originally Posted by Pooter

Thanks for the info. I am completely happy with 240-250bhp. I've never been into sports cars until I bought my Elise a few years ago. I got into offroading and building crawler rigs that only see about 5mph top speed on the rocks. To be honest, the Elise was plenty fast enough for me in NA form. I'm sure this factory supercharger will take me right to the edge of what I am comfortable with as far as speed/capability. I am the idiot that always pushes the limits of modification with all my fun cars, so it'll be nice to know that I am not sacrificing reliability with this supercharger setup. I don't plan on getting crazy with this Elise until I pick up a first gen NSX for a daily.

No problem. If you don't mind if you could verify (even a rough verification with a tape measure) that the blower pulley you have on your m45 is in fact about 2.7". That would be great info to both verify your setup and good to know for others that search your thread in the future.

If you are coming from NA even a mild supercharger kit like the m45 including the other modifications will be a VERY notable improvement. You will love the low and mid range torque I bet. Sure it may not be a ton of power but a nice bump and if you got everything for a good price then why not! Keep us posted on what you think of everything once its all installed and dialed in

[Pooter]

Maybe my tape measure is inaccurate... but it measures about 2.5". It has 67.7 printed on it though, if that means anything.

[WhatsADSM]

Originally Posted by Pooter

Maybe my tape measure is inaccurate... but it measures about 2.5". It has 67.7 printed on it though, if that means anything.

Awesome thanks for measuring!

67.7 would be mm. So yea about 2.66". Yup the stock 2zz crank pulley and that blower pulley definitely has the flow for 240-250.

[Pooter]

Originally Posted by WhatsADSM

Awesome thanks for measuring!

67.7 would be mm. So yea about 2.66". Yup the stock 2zz crank pulley and that blower pulley definitely has the flow for 240-250.

Cool, that's good to know. So here are a few details about my setup... VisionFunction intake, ForceFed header, decat, and Arqray single tip exhaust. Jermaine from VF will likely be doing my tune (I'm sure he'll be able to really dial it in). He actually has my ecu right now adjusting the fuel trims for my NA tune that he did for me last summer.

I'm hoping that I have enough bolt-on stuff to get me up to 250hp. That'd be awesome.

[LJ60]

any pics? are you bolting it on already or just gathering up parts I'm curious to see how a stock m45 off elise sc is going to bolt up without the lotus intake

I have a 2005 minicooper S, these use the m45. these come from the factory with about 168hp at the crank. 1.6 liter engine with top mounted intercooler. my car has a header, 15% underdrive pulley, CAI and cam. car makes about 212 hp, 180 torque at the wheels. torque curve is pretty flat. so i think this supercharger can make some power, but i'm wondering if you can add an intercooler with the intake that you are using.