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

    • I seem to the be only person that is using a Haltech 2500 on an NA motor, I've installed a Bosch DBW throttle body to the OEM intake manifold and am having problems maintaining AFR even with the wideband o2.  It will run extremely rich at idle and up to redline, but under load it will go extremely lean in the 20s and i'm essentially having to rev it over 4k and feather the clutch to get it up to speed.  I've read a few other threads of about the butterfly, it seems removing the vacuum to it is supposed to have it remain open, i've noticed no difference under 4k with the vacuum line to it plugged.  I'm hoping someone here has had luck using the NA manifold with Haltech, and if they happen to have a tune for it.  
    • I don't know any details, but I really wouldn't be surprised if they do it as a LHD only version, at least initially.
    • Thanks for the replies everyone. Definitely a coolant push. Oil catch can is empty and always has been. As the engine is out now I'll be having a good look over things. I do have some detonation on the piston tops from a trigger issue back about 5 years ago. I felt it and shut off then bought a new ecu and changed the trigger. Never been an issue since. It never hurt the power, its made almost 80hp more since that incident but I will pull the bearing caps to take a look. If the bearings are damaged I will do a bottom end refresh. Head is being re conditioned at the moment and the block will be cleaned and checked to ensure it's flat. I'll go with a kameari gasket and see how it ends up. The other thing I'm not super keen on is the cylinder colours. I suspect this is from the inlet manifold. The plan will be to put it back together, retune and then stick a plazmaman billet inlet on it and retune. I'm happy with the power, if it makes a little more, then great, but I would rather just make everything more efficient at this stage.
    • Maybe they'll look to do a bunch of presales to help inject some cash fast for their financial issues...
    • Does it also misfire equally when revving?   Josh is very correct in what you should do. The coilpack harness wiring loom itself is a known problem due to its age and the number of heat cycles it has gone through. Throwing parts at a vehicle to diagnose the issue isn't a smart or good way to do it. Secondly, you may have a bad coil pack, you pop replacements in, they fix that issue, but messing with the harness breaks it, so the issue persists. So now you think "well it wasn't the coil packs" and have to continue chasing your tail, potentially swapping back in your shit coil packs and returning the good ones (yes, I've seen people do this because 'it wasn't the problem' and they want to save money). And suddenly, you've got two issues with the same symptoms...   Diagnose, don't use the spare parts shotgun.
×
×
  • Create New...