Ok guys, im getting the car mapped a week on friday, on the already installed simtek, when first discussing this with mapper, he asked if any of us had thought about running meth mix map, and it got me thnking.

I have a my94 sti, with full decat, induction kit, walbro pump, front mount, 440 injectors and td05 16g, and ported headers and up pipe

Im only lookng for somewhere in the region of 330/340 bhp and as close as i can get to this with torque as well.

I only use the car at weekends and the odd run at night to a club meet, after doing a bit of reading it seems the meth needs to be used fresh, i.e it goes off in tank after a period of time, so im looking for some slightly more difinitive answers if possible.

How long will it last in tank?

What happens if im not completely out of meth/v power mix before switching maps in car, or likewise the other way round??

How easy is it to mix? Im guessing you would buy a barrel, pour into measured recepticle and add in tank to a certain level of fuel already in there?

Am i jumping the gun Using it on my set up? The only reason im considering it is the gains in power with the same mods over straight v power.

Any help appreciated

 

Subscribed.

Watching this thread with interest as I'm in a very similar boat chap.
Let's hope the gods are on tonight so we can get some answers.

 

Yep, thats what im hoping to mate, i might well be jumping the gun with it all, i know the set up i have is good for the power im looking for using straight v power, but fancy the idea of the lower combustion temps and general safety of using the meth mix.

 

What AFR would you map to on a meth map 12:1 ? sounds interesting

 

is it a separate meth tank or just dumped in with the SUL?

 

Afr is in and around 12:1 from what ive been reading about, guy on nasioc was running 11.7:1.

Putting it straight into tank with fuel

The other thing i picked up on whilst reading the thread on nasioc is that pump systems although havnt been reported to fail on a subaru up until now, can happen and have happened on other makes of vehicle, simtek having no knock control could be catastrophic if it went pearshaped, however, far less to fail when adding it to tank with fuel mix, only what you already have feeding the system?? Is there anything else within a standard system that could perish as a result of using it, not very kind on rubber from what ive picked up, but not sure it would actually come into contact with standard rubber, only the proper fuel standard hoses already used.

 

Subscribed,I'm going for a meth map on the 15th and would like to hear all about the draw backs involved with it.
I've got a KS3 knocklink so watching knock is not a problem but like most here I only use the car on weekends.

 

Whos doing your mapping mate? Same day as me

 

when i looked into meth i decided on putting it straight into the tank. no risk of the meth injection breaking while you're going full belt and killing the engine.

having it in the tank means constant consistency plus good mappers like jgm will put a fail safe in so if you're slightly under the mapped amount it should be safe. i always ensure i have just more than what i mapped it on. 5 litres of meth per 25 litre of petrol when i mapped it at around 5 litres of meth per 30 litres of petrol.

simtek built in knock detector means no knocklink is required. dash engine light flashes if knock is detected in which cash you either swap to petrol only map temporarily or pull over and top up the meth level.

 

Not sure about how quickly it goes off but here’s my opinion..

Your meth weight must always remain constant. For example, if 20%, if you put in 40l of petrol you need to put in 8l of meth. Sounds obvious but you can’t put in 10l of meth (say if you estimate a 50l tank which is near empty) and then brim the tank with petrol. You must be disciplined at all times.

Switching between a meth mix and petrol will be a pain. Once you have used the mix tank, you will need to run through another couple of tanks of pure petrol before all the meth is out of the system as you will have driveability issues. The same applies the other way round. If you're bothering, you're better off running the mix permanently.

Up to you whether you can be bothered. IMHO, it isn’t worth the hassle unless it is a track car or at least weekend only fun where you can fanny around ensuring sure you have the correct mix. Nice gains to be had though.. good luck!

 

Simtek does have knock detection, but no control of it which worries me with the pumped systems as it could go pop very quickly if anything fails, at least thats how i understand it at the moment, lookng for those in the know to give the pointers required and any additional info in order to decide whether to go for it or not, prime concern for me is safety of engine as far as is possible.

 

What sort of power gains are we looking at ?? For instance with a 10% mix. Also, what mixture is most commonly used, 10%, 20% etc etc and what differences in gains using say 20% over 10%.

 

The car is nothing more than a toy for weekend use, and the odd night out to a club meet so no worries there, it cant possibly be an exact science when using the in tank method, as you will never know exactly what you have left in the tank in order to put the correct % meth in tank to mix to?? Am i right? Or is it a case of run tank as near to empty as poss, fill with say 40 litres and add correct % meth and run till back to near empty again as near as is possible, and repeat??

 

As you can prob tell, ive only just started looking into this, but from what i understand you can run whatever percentage you like, andy f runs 50/50 i believe, most run around 10/20% meth and the rest v power, which gives different gains on diffeent cars, one example i have seen is on 20% mix gains of approx 40bhp and similar torque over straight fuel, havnt seen difference in gains between 10/20% but will keep looking into it in more detail.

 

who's mapping your car? speak to them. they will have mapped meth into so many car that they will have a much better idea. plus JGM runs meth as well.

agree that the pumped (meth injection) systems are dangerous. all it takes is a few moments where the pump stops and that could be it, game over.

You don't always have to run it exact. You can run slightly more safely but NOT less. If you had to have the exact amount in each time then mappers wouldn't be able to map in a safety margin. It's a similar principle to a standard car running on vpower when it normally runs on standard petrol, the additional octane level isn't going to damage the car. Doing it the other way round would though if you're mapped specifically for the higher octane fuel.

if for some reason you don;t have any meth with you it's no problem. i just run it to less than 1/4 tank and fill up with vpower then switch to vpower map. having a little meth in the tank isn't going to damage the car, it just won't make the most of it. plenty of people have asked if they can put meth in without a remap and mappers have said yes so long as the quantities are low. they recommend a remap to make the most of the meth. when you go back to running meth i just assume the tank is all vpower, put 20% of the tank in meth then fill it to the top with vpower. simples

 

I've been running a meth mix for the last couple of years... I pop in 10L of meth into the tank and top up with V Power, usually get through a couple of tanks every 10 days!

IMO it's a no brainer, go for it on top of the power gain i love the feeling of paying £50-55 instead of £65-70 at my local shell

 

Where do you boys get your meth from?

 

I get mine from jennychem.co.uk

 

Basicallly the impreza fuel tank holds 60litres so 10% meth u add 6litres and top up to a full tank and 20% will be 12litres and top up to a full tank

 

Just had a look at jennychem, they do a 25litre or a 205 litre tank, working out prices without the dreaded as im not sure its applicable, its 98p for the smaller amount and 67p for the larger, which isnt bad, on 10% mix the larger barrel would last approx 34 full 60 litre tanks, not bad at all.

 

You would need to buy the 205 to make it worth the ballache IMHO

 

Think you might be right stu, be a pita for the sake of 25 litre at a time, and a lot more expensive

 

Twice the price at 25 litres !

 

I've got a 205 litre barrel on its way to me now,WITH A FREE PUMP

 

What's the legal stance on using it as I presume no road fuel duty is built into price, also if you happen to have a vosa check can they find it in your system. Although highly unlikely to happen best to know in advance

 

Thats a very good point, hadnt thought of it from that side, be interesting to find out what consequences if any are applicable, although like you say pretty unlikely, theyd be far more interested in my bald tires and decat!! Lol

 

you dont use as a fuel do you, its for cleaning purposes only, valves, injectors etc

 

Just looked on their site, £135 for the barrel. What was the delivery charge buddy ??

 

http://www.dtchemicals.co.uk/index.p...uct_detail&p=2

 

Cheers for that, thats a good price!!