QuickOne

iTrader: (2)

Having tuned a great number of cars through the years, one of the new "in" things seems to be meth/water injection.

My question is this.. Why not just put more fuel in?

It seems pretty simple to me. AFR = #parts of air/ #parts of fuel.

Once you hit this, you're at whatever afr you want. One of the nice side effects of fuel is that it also cools the charge. Not to mention you can retard the timing if you're still burning fuel during the exhaust cycle... I've tuned many cars using this method (including a 600hp 2.0L wrx) and never had to result to meth or water injection

My problem with both of those is taht I do a lot of road racing. And while i have plenty of things to worry about, trying to remember if i re-filled the meth/water tank is not something i care to think about. Plus, i don't want to have to run a different map whenever i run out of either of those and are in a location where i can't easily get it.

Thoughts?

Jeff_Jeske

iTrader: (66)

Very few people actually use water. Most use meth or alchy. Both will cool the charge much more than pump gas and both will virtually increase the octane of the charge.

Ev0ikon

iTrader: (18)

The answer is 93Octane+Methanol is cheaper than RaceGas while making almost he same power.
your comment about forgetting to refill is kinda silly. :}

ExViTermini

iTrader: (25)

it comes down to two things. The biggest one being cooling, and then octane to follow.


Theres only so much boost you can run on a certain setup before you reach a knock threshold and cannot push anymore out of the engine on pumpgas. You could simply put in race fuel and tune for that and be done. However the majority of us would rather be able to fill up at any gas station we want and still run crazy boost.

We want our cake and eat it too.

Meth/Alky also has a severe cooling effect, allowing to turn the stock turbo to boost levels past its efficiency. Once you reach past the effieciency the temperature of the air skyrockets, but the meth cools it back off. With the increased boost comes more torque

Ultimate CC

iTrader: (122)

Added fuel won't give you the added octane and it won't give you as much cooling as methanol would, methanol is also cheaper than gas in most areas...

QuickOne

iTrader: (2)

I understand all of that. However, i'm talking about a properly setup car. Basically, i have a 3076 that i want to run 25-28psi on the street with 93 only. I have no desire to run meth/alky or anything else to augment the fuel.

With it properly tuned (perhaps 1000cc injectors or something) i should be able to pull enough timing out, and add enough fuel in to keep temps down and to keep knock away. And that turbo should be efficient enough at those boost levels to handle that..

Think it's possible with that setup to run a pump-gas only tune?
If not, then why?

Ultimate CC

iTrader: (122)

You can certainly run a setup like that but you will not great the full potential out of the turbo...

DarksideEng

iTrader: (38)

It will reach a point where you cannot go any higher. You will probably be reducing so much timing it would be better t run 23psi and run good timing numbers. The meth is just icing on the cake and allows you to push timing and boost while using pump gas and not run into the knock threshold.

SlowCar

iTrader: (4)

bore washing.......fuel in the engine oil......from an overly rich charge which still combusting in the exhaust manifold....whats your EGTs?

Jeff_Jeske

iTrader: (66)

I would have to say your idea of running 25+ psi on pump gas alone is very silly. No shop in their right mind would tune you for that.

As mentioned above there is a limit to what you can get out of pump gas. Even if you add a ton of fuel and pull timing to fight knock at that boost level your power will probably be worse than a "normal" tune at lower boost. Keep in mind there is a thing call rich knock as well. The gains from a higher octane mix comes from more than just boost. Adding a few degrees of timing and leaning out the AFR provide almost as much punch as adding boost.

Most of us that do not like to rely on alchy/meth have two maps available to them. I have a 20psi daily pump gas map and I have a 25psi (plus timing and leaner afr) 100 octane map.

I have a couple of 5 gallon containers in my garage filled with 110 octane. On weekend or race days I split that stuff with 93 for a 100+ octane mix. Night and day difference.

Mercenary3

iTrader: (1)

Pulling that much timing will prolly send your EGT's way too high.

If running 25-28 psi is even possible without melting stuff, shops would be doing it if it made more power than 21-22 psi with more normal timnig numbers. My guess is that at 28 psi you will be making less power with all the timing you need to pull, and your egt's will also be dangerously high. Not to mention you will be backfiring constantly, getting TONS of fuel in your oil, possibly cracking exhaust pieces, destroying 02 sensors....etc.

But by all means, if you have the instrumentation to ensure a safe running car, go for it. Its your machine. Although Im not sure why you would risk your motor just becasue you dont want to run high octane fuel or a charge cooling system.

Also, fuel (gasoline) serves as a very poor coolant compared to water and alcohol.

Warrtalon

iTrader: (6)

I don't understand how you have experience tuning a 600whp car but think you can just add more fuel to make up for alky. That doesn't make any sense at all. Why would you want to add a lot of fuel with a low octane (e.g. 93), which makes it rich while also reducing timing. That would reduce power, not increase it. The meth/alky lets you run aggressive timing AND extra boost. You could take your 3076 and run 30psi on 93+meth - that would make a good 50-70whp more than 26-28psi on straight 93.

You won't get near the turbo's potential on straight 93. That's fine if you don't care, but do not think that simply adding fuel while removing timing is a way to make up for alky injection. That's nutty logic.

Remembering to refill the alky tank is a no-brainer - it's like being low on fuel. I refill my little 1-gal alky tank once every 2-3 gas refills. I also road race, and I just refill after each session - I use about half a tank, but I want it to be full each time. It's no problem. Also, my kit has a low fluid warning indicator.

As for the tuning, I have 4 maps and use EcuFlash to switch between them depending on what I'm doing (auto-x, drag, circuit, street).

QuickOne

iTrader: (2)

Contrary to what everyone in this thread seems to think, i'm not trying to replace meth/alky. I'm trying to stay away from it all together. I want to run a pure gasoline car that makes 400-450 whp without all of the extra gadgets.

My point about adding fuel/pulling timing on previous cars was all part of the tuning process. Of course, i could have made gobs more power with 100oct and a race gas map, but, I don't have 100oct readily available to me (and i'm not going to get a 55gal drum to put in my garage)..

This car needs to be regularly fueled on 93oct and will only have limited time on anything else.

These cars have been making well over 500hp for years. Meth/Alky injection (in augmenting regular gasoline - not 100% meth/alky injection) is only a fad that has started recently. And honestly, i don't think it's needed.

As soon as I get my new ems, i will be trying this method before going to anything else.

Jeff_Jeske

iTrader: (66)

Unsubscribed.

Wolf28

iTrader: (3)

Because you just heard about injection it is a new fad? The Supra guys have been doing this for YEARS!

I have my reservations about meth inj as well (pump fails and car can go boom ral fast), but if you can't or won't run 100+ oct there really is no other way around it if you want to near the turbos full potential