Jump to content
SAU Community

Recommended Posts

How can it lower intake temps, it is only sprayed on to the intake valves. Ethanol would definitely cool the pistons more for a given power output but that just gives you a reason to heat them up some more.

I saw 900 degree temp in my manifold at Sandown running ethanol, if you push hard enough it still can still melt things, just at a much higher output.

How can it lower intake temps, it is only sprayed on to the intake valves. Ethanol would definitely cool the pistons more for a given power output but that just gives you a reason to heat them up some more.

I saw 900 degree temp in my manifold at Sandown running ethanol, if you push hard enough it still can still melt things, just at a much higher output.

How can it not cool the intake charge? Alcohol evaporation will reduce temps

Can you work out for the kids at home how much it will cool the intake air in the microsecond it has before it enters the cylinder, at the speed of sound? I doubt it would even register on your calculator.

Yes the ethanol will cool the charge slightly in the bore but it is a minuscule amount, and would more help slow the air heating imo. (it definitely won't be cooling it down inside there at wot.) If you want to cool the intake charge you would need to spray the ethanol much further back in the intake to give it time to evaporate. I think if you are that worried about the intake temps by that point you have other issues.

We are much better off trying to cool the bore, as that is going to produce more heat than any other part obviously. Direct injection of water into the bore on the exhaust stroke sounds like a better option to me. I will be trialling it soon on a high comp VQ25DD running e85.

It's not the temp in the plenum that matters

It's what reaches the chamber

Alcohol works wonders for cooling, look at methanol drag cars, they don't really need radiators (or very small ones at most) as with big rads they don't get up to temp

E85 won't cool as much as not as much is used (plus chemical differences)

But I'm sure a rich e85 tune would be nearly as good

Cheers for the Input guys, i'll stick with the intercooled E70 setup then. What excites me is a single turbo manifold for the VG30DETT has been developed, and my next engine will have a built bottom end and a precision 6466 hanging off it ;)

Can you work out for the kids at home how much it will cool the intake air in the microsecond it has before it enters the cylinder, at the speed of sound? I doubt it would even register on your calculator.

Yes I could

please correct me if Im wrong but everybody keeps comparing wmi with E85 sure it helps you run bit more boost and timing on boost but I don't believe you will get the OFF BOOST gains with wmi and just how much better your motor runs fullstop on ethanol :)

I think the focal point here is that lower charge temps help reduce combustion temps and its high combustion temps and pressures that help promote detonation - depending on how well developed the engine is to start with .

A .

I can't remember the exact chemically correct AFR for petrol E85 and methanol but I think it comes out something like 14.7:1 / 8.8:1 / and ~ 6:1

Whatever fuel has to vapourise because most fuels as a liquid don't burn too well . Throwing in approx 1/7 of the total charge mass as a vaporising fuel would make methanol a virtual freezer compared to petrol . E85 would be almost 1/10th the charges mass and petrol approaching 1/15th .

I'd say the greater the charges fuel mass is the greater the evaporative cooling will be provided it changes state to a vapor that is .

Can you work out for the kids at home how much it will cool the intake air in the microsecond it has before it enters the cylinder, at the speed of sound? I doubt it would even register on your calculator.

Yes the ethanol will cool the charge slightly in the bore but it is a minuscule amount, and would more help slow the air heating imo. (it definitely won't be cooling it down inside there at wot.) If you want to cool the intake charge you would need to spray the ethanol much further back in the intake to give it time to evaporate. I think if you are that worried about the intake temps by that point you have other issues.

We are much better off trying to cool the bore, as that is going to produce more heat than any other part obviously. Direct injection of water into the bore on the exhaust stroke sounds like a better option to me. I will be trialling it soon on a high comp VQ25DD running e85.

when we say intake air it would obviously be after the injector, how would it possibly be anything else.. the ethanol would be vapour going into the cylinder and have its cooling effect then, if it was anything but atomised/vapour then surely the engine wouldnt be running too well because it would be trying to compress a liquid would it not? I would imagine it would be like throwing some water on a hot pan, instant vapour and reduction in heat .

I doubt drag cars would not have a radiator because there running methanol, wouldnt it have more to do with only running for 400meters and for like 2minutes?

Edited by SliverS2

when we say intake air it would obviously be after the injector, how would it possibly be anything else.. the ethanol would be vapour going into the cylinder and have its cooling effect then, if it was anything but atomised/vapour then surely the engine wouldnt be running too well because it would be trying to compress a liquid would it not? I would imagine it would be like throwing some water on a hot pan, instant vapour and reduction in heat .

I doubt drag cars would not have a radiator because there running methanol, wouldnt it have more to do with only running for 400meters and for like 2minutes?

They generate a lot of heat just from HP but it saves weight and there is enough cooling from the fuel to get them to the finish line. They shut off after that and get towed back.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • BOVs do have a purpose, if you ever log pressure before and after the throttle body, you will see a spike pre throttle on lift off from a WOT condition. Enough to bend throttle blades / damage e-throttle motors or simple assist in blowing off cooler pipes. FWIW, the above on really applies to those running at least 2 bar of boost. OP shouldn't have an issue, on the other hand, here are some videos of my shit box over a decade ago with some succulent dose with the airbox on and off. That shit box is unrecognisable these days 馃珷    
    • I've tried all different combinations of BOVs/ no BOV and stock bypass valves over the years, on gear changes the stock bypass valve seems to get the car back on boost quicker because in part the turbos wheel speed isn't being slowed down by reversion, although they have issues holding boost much over the stock setting. Most aftermarket BOVs you can adjust the spring, tighter will make it open later and close sooner, but in my experience it'll cause a bit of flutter at low load/rpm anyway. I've also got some input into this whole no bov causing turbo wear, never had an issue on any on my turbos HOWEVER, I got my R33 GTST with 200k kms on it, with from what I can see still has the original turbo, no lateral shaft play but has about 4-5mm of play in and out which to me seems like a worn thrust bearing from years (100-150k kms?) of turbo flutter running no bov, so maybe there is some truth to it in the long run. But that'll never stop me loving the Stutututu while I have the car.   OP just wants to know if he can run a atmo vented BOV with no major issues and the answer is YES, plenty of people do it, there's no harm in installing it and seeing how it runs before spending $$$ on an aftermarket ecu, last time I bought a Nistune it was $2400 for install and a tune , unsure of todays prices but you get me. Crazy money to spend just to fix the minor inconvenience of stalling that can be overcome by letting the revs come down to near idle before putting the clutch in or a little bit of throttle to avoid it. You're better off leaving the ecu and tune for after a bigger turbo/injectors have been installed to take full advantage of the tune and get your moneys worth.   Let OP have his Whoosh sound without trying to break his bank haha
    • I see you missed the rest of the conversation where they have benefits, but nothing to do with avoiding breaking turbos, which is what the aftermarket BOV made all the fan boys, tuners, and modders believe was the only purpose for them...
    • But they do so for the other reasons to have a compressor bypass. It's in the name.
  • Create New...