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

    • Don't use that manifold. Please don't use that manifold. Sunk cost fallacy is not worth the later pain. None of these will be relevant to the change that will come from the different turbo and manifold. As in, the effect of the exhaust will be nil, regardless of what else is changed. And all the cam and fuel system stuff is not changing either way, so has no effect. The turbo and manifold (and to a small extent the wastegate)....big change.
    • Just wanted to say thank you for your input   my man (lead mechanic by trade) and I have done a heap of work as you can imagine just to make the hot side work with the dump pipe, stupid massive intake on turbo, trying to get the waste gate on was not fun.  I’m kinda getting to the point where I don’t know if I try and make this work and not throw all this cash and time away or do I scrap the lot and start again? the Apexi I’ve got was tuned for a few slight differences:   Tomei pon cams (mine are stock neo) Turbo smart 38mm external waste gate (mines 45mm replumbed) with stainless screamer pipe  3inch turbo back exhaust with high flow cat Sard 800cc top feed injectors Sard adjustable fuel pressure reg    
    • Out here E90s are the cheapest way into a sporty-ish car because everyone knows just how expensive the repairs can get. 8-10k USD for an automatic 335i. 
    • Noted. Have noticed BMW are more 'high maintenance' for sure. They've attracted my attention as I think the used car prices seem reasonable vs other options, and the extra quality overall vs a commodore / camry / corolla or similar of the same vintage is appealing, especially the interior, and they are more on the sporty side whereas the others mentioned can be more cruising or economical A-to-B only.
    • Haha yeah I know, this is SAU after all, why are we talking about BMW's of all things!? I hear you on the 'don't have to worry about it' side of things. Having been fortunate enough to be have been able to buy a brand new motorbike or two...never really enjoyed them as much as I'd have liked as you worry so much about where you park it, will it get scratched, stolen, attempted theft, knocked over, etc...and yes dirty. Older less valuable bikes you can just go where you want and park it wherever and not really worry that much in comparison. And who cares if it gets dirty! Never owned a V8, and have had my eyes on VE / VF commodores for years but with their prices climbing so high, the M3 has come into focus more as prices are much closer than I've ever seen...is it a potential contender now?...of course need to factor in the S65 'maintenance' especially and like you said general M car 'tax'. One can dream anyway. But more on the reality front - did read the whole 330i thread as well and was a great read too, both threads enlightening as I've never even driven one of these cars! I do recall 330i didn't seem to have the same amount of issues for almost the same car (turbos and related differences notwithstanding)...perhaps down to getting it earlier in it's life so looked after better than the 335i? Perhaps so as your 130i has been good and quite similar, so finding a car that's been looked after well is the especially-crucial-BMW-first-step.
×
×
  • Create New...