Meth Injection vs Intercooler

Prince

Torque King
Points
242
Location
Northampton, England
Car
BMW E36 318is Coupe
Long story short I'm planning to supercharge my engine sometime early next year. I would like some kind of cooling for it.

What are the benefits of meth injection vs intercoolers as I think I'd be more likely to go meth as the setup should be easier.

Thanks!
 
The 'charger doesn't add as much heat as a turbo. It's just to keep things sweet. According to my research so far meth isn't really needed until 12-15 psi. I plan to run 10 psi.
 
If you're going to use a roots type charger with the standard compression ratio, you would be mad not to use an intercooler.
 
If you're going to use a roots type charger with the standard compression ratio, you would be mad not to use an intercooler.

It is a roots type charger, but why does the CR matter? The 'charger doesn't increase it.

The problem with an intercooler is how to fit it. The SC replaces the intake manifold.
 
the higher the cr, the earlyer you will hit knock, lower intake charge = later knock. is this going on the BMW? why will the SC replace the intake manifold?
 
the higher the cr, the earlyer you will hit knock, lower intake charge = later knock. is this going on the BMW? why will the SC replace the intake manifold?

It's designed specifically for the 4 pot E36 and Z3s. The kit looks like this before installation and like this fitted:

SHOPPICSdec9th020.jpg


Where it sits above is where the intake manifold is. I don't know why, but that is how it's designed.
 
The 'charger doesn't add as much heat as a turbo. It's just to keep things sweet. According to my research so far meth isn't really needed until 12-15 psi. I plan to run 10 psi.

How can you say that? Different turbos/chargers don't have the same airflow at the same boost.

If you're not lowering the CR, you will be stuck to low boost and be wanting to keep intake temps as cool as you possible can as Claymore has already explained. It's all school boy stuff really.
 
I'm not overly impressed by the design of that manifold. looks like the boost will favour cylinder 1 and 2, would be quite dificult to get the fueling right.
 
How can you say that? Different turbos/chargers don't have the same airflow at the same boost.

If you're not lowering the CR, you will be stuck to low boost and be wanting to keep intake temps as cool as you possible can as Claymore has already explained. It's all school boy stuff really.

The PSI is raised by changing the pulley. The kit comes with a 3.6" pulley and runs at 8psi, a 3.4" should run around 10psi and a 3.2" is supposed to run at 12psi.

I plan to use the 3.4" inch pulley. Even though I've found that meth injection isn't required at this stage, I think it would still be a good idea to keep things as cool as possible.

Well, there you go then :), meth is the only option with that setup.

Thanks mate! So my next question...

Are there different meth kits or are they all basically the same thing?

You're screwed LOL.

Well that's helpful. ;)

I'm not overly impressed by the design of that manifold. looks like the boost will favour cylinder 1 and 2, would be quite dificult to get the fueling right.

Once everything is up and running I'll be going for a custom map. I'm planning to stock pile parts over winter and then get it up and running around March time next year. I just like doing my research early.
 
You'd need to use water and methanol, or just plain water. 10psi on 10.5:1 like I said before is a little on the high side so water/meths would be required for piece of mind.

Also Clay is right, it would appear that the charger will favour 1 and 2 cylinders but I dare say at this level it doesn't matter so much.

Also any form on forced induction on any engine does increase cylinder pressures (not to be confused with compression ratio) which is a contributing factor of making more torque, (much more so than power)

My advise to you is to use some water meths as it is the easiest option for your install and get it mapped proffesionally. Water has the potencial to coller you intake temps down more so than any intercooler. The closer you can get your inlet temps to abiant on a forced induction engine the better as it will run better and is less likely to suffer from pre-detonation.

As for what brand kit, I use a DevilsOwn Base kit (kind of an on/off affair) but they do progressive controllers which adds water/meths in proprotion to how much boost pressure your charger is pumping out.
 
I do try and be subjective, it's all well and good say something is rubbish or good but I always like to know why or give a reason myself. Just saying something is rubbish just starts agruements rather than proper rational debates.

Also P, what oil do you currently use? and what plugs do you use?
 
Also something to consider is that running 10 psi on your engine is going to equate to around 250 hp and 220lb/ft of torque, and the fact that you're running 10.5:1 compression ratio does mate me concerned because you're probably at the limit of what the engine is prepared to take in terms of cylinder pressure and you could become "unstuck" (throwing a rod) Hopefully this won't happen and I don't wish this on you, but it's not the power and torque figures that kill engines, it's cylinder pressure coupled with high thermal loading. For example, A 306 gti6 engine is a brilliant base for tuning but if you drop in some 12.5:1 pistons and some cams it will throw the standard rods out of the side of the block (big mess.....) that stuff along with supporting mods will see no more than 270hp, 170-180 lbft torque (probably more like 250 ish), if you decomp. the engine then you can use a turbo and I've seen gti6's run 400 hp and 300lb/ft from just a decompression plate and a turbo of course with no fancie forged internals. So just take it under advisement that if you want more than that then you will need to devise a way of running a lower compression ratio so you can use a higher boost from the supercharger.
 
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I do try and be subjective, it's all well and good say something is rubbish or good but I always like to know why or give a reason myself. Just saying something is rubbish just starts agruements rather than proper rational debates.

Also P, what oil do you currently use? and what plugs do you use?

I agree mate. Way too many forums have way too many arguements just because something isn't explained.

Oil is valveline 10w 40 and plugs are oem. Service is due soon though. Will any of this make a difference?

Also something to consider is that running 10 psi on your engine is going to equate to around 250 hp and 220lb/ft of torque, and the fact that you're running 10.5:1 compression ratio does mate me concerned because you're probably at the limit of what the engine is prepared to take in terms of cylinder pressure and you could become "unstuck" (throwing a rod) Hopefully this won't happen and I don't wish this on you, but it's not the power and torque figures that kill engines, it's cylinder pressure coupled with high thermal loading. For example, A 306 gti6 engine is a brilliant base for tuning but if you drop in some 12.5:1 pistons and some cams it will throw the standard rods out of the side of the block (big mess.....) that stuff along with supporting mods will see no more than 270hp, 170-180 lbft torque (probably more like 250 ish), if you decomp. the engine then you can use a turbo and I've seen gti6's run 400 hp and 300lb/ft from just a decompression plate and a turbo of course with no fancie forged internals. So just take it under advisement that if you want more than that then you will need to devise a way of running a lower compression ratio so you can use a higher boost from the supercharger.

It should be around 220-230bhp at the fly. Torque isn't quite that high, but not far off. The M42 engine is a very strong unit (often used for turbo conversions is the States). I'm starting with the 'if it's not broke don't fix' view to things, whilst I learn how to use it properly. The engines are cheap enough to buy so if worst comes to worst I'll have to go down that route.
 
I'd use a heavier grade oil, something like a 10w50 and make sure it's an ester base stock fully synthetic. I use Fuchs/Silkolene Pro Race S, I was using 5w40 but I've just ordered some 10w50 for this engine. Also get some plugs that are a grade colder and I can recommend NGK or Denso, mutli pole plugs don't gain you anything interm of performance just go for the iridium tipped ones.
 
I'd use a heavier grade oil, something like a 10w50 and make sure it's an ester base stock fully synthetic. I use Fuchs/Silkolene Pro Race S, I was using 5w40 but I've just ordered some 10w50 for this engine. Also get some plugs that are a grade colder and I can recommend NGK or Denso, mutli pole plugs don't gain you anything interm of performance just go for the iridium tipped ones.

Thanks for that mate! Do you think it's worthwhile carrying out a normal service then re-servicing after the 'charger is fitted?
 
Might as well do it then!, I reckon the 10w50 will be ok in the Fuchs Pro S, but do check with Tim and Guy before you buy as they are the experts.
 

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