Been talking to Prawn and he swears by his Water / Methanol injection. It massively reduces inlet temps on track. This seems to be pretty common on 1.8T`s, where the stock Turbo is small, so people try pushing the limits and find W/M injector helps a lot. There are a couple of ways of approaching this. The intercooler sprayers that simply spray water to the outside of the intercooler and that evaporates, cooling the temps. The Simple W/M systems that spray a mix of water & methanol into the inlet pipework, after the intercooler, operated by a pressure switch The more complex phased systems that increase the amount being sprayed as boost rises. In the US, the parts required to build a DIY system are readily available, less so in the UK. I`m looking into the benefits of fitting a simple DIY system. This will be operated manually, by a steering wheel mounted push button. Think of a summer trackday, 30+ Ambient. A circuit with a long Wide Open Throttle main straight and a Turbo car. Rather than have the W/M running all the time on a boost / throttle setup, I`d have a button I could press when on the long straight, just cooling the inlet for that section of track, which also happens to be the one that builds up most heat. By doing that, you also massively decrease the use of the W/M over a trackday too. So, after some googling, there are many useful things out there, many with US suppliers. This is a particularly useful site Is seems that the main things you need to buy are a decent pump (SHURFlo seems the most popular). The #8000`s series give enough pressure to atomise the water properly. IE Shurflo 8000-946-138 12v Pump for 76 Next up is a Solenoid or check valve to isolate the pump when not in use. There doesn`t seem to be a particularly cheap solenoid or check valve that has been proven, so I`m unsure if that`s somewhere money could be saved ? Same with the spray nozzles. I don`t see the benefit of saving a few quid if the nozzle that does the spraying isn`t very good. Old washer bottle in the boot and some tubing is no issue, neither is the activation switch. If you wanted to connect up a pressure activated system, that`d be pretty easy too. I wouldn`t be changing the map to take advantage of cooler inlet temps, that`s just asking for trouble if you have an issue with the W/M setup. What I`d do is leave the map and everything else untouched and have the W/M as an extra that helps when it`s working, but doesn`t cause issues if it runs out of fluid or stops working. So, why is it a good idea ? Why is it a bad idea ? Apart from mapping it to take advantage of the W/M injection, then having issues if it fails or runs out of fluid, I`m struggling to see many downsides ?
Interesting as my Father had one of the first Saab 99 turbo's, a two door one in red with the pyramid type wheels and he got hold of a water injection kit from Saab that knocked it up from the std 145bhp to around 170bhp, which was a lot of power back in 78! They sold it as a conversion kit as the two door was a homologation model for the rally car, I think it was an optional extra on some of the later 99 3 doors - any way I digress. Once fitted you just pulled the waste gate spring out or something like that and stretched it to the new dimension (all K jet back then!!). Knowing my father it was stretched twice as long as it should have been!! Anyhow it used to go nuts from then on, it would spin the wheels in third when it came on turbo (big laggy turbos back then), we reckoned it was closer to 200bhp as it really did go! My point is, that even though it was all clockwork and pretty potent (relative to the technology) it held together with the water injection fitted for 100k. That said it was then well worn by 100k, but this was in the day when Castrol GTX 20/50 was the oil of choice! Saab recommended running a % of meths with the water, maybe it helped with detonation, but also as an antifreeze. As I recall the feed was from the washer bottle. In summary it was a very simple system, not overly complicated, and helped the motor hold together given the fairly primitive nature of turbo charging cars back then, so probably a good move. Also Spitfires used water injection on the Merlins in WW2, so it must be good
What sort of pressure and volume of fluid do you need ? I reuse an old fire extinguisher for squirting on my incinerator when it gets a bit wild lol I 3/4 fill it with water then pressurise to 150 psi and have 9 ltrs of water to squirt when empty undo top fill with water connect nozzle to air line and pressurise Injector nozzles work ? Old KR ones or ABF electric ones ?? Just musings so tell me if I'm being stupid lol
Fuel injectors won`t work. They`ll rust. I have looked at that already lol I pre-pressurised cylinder isn`t really ideal. You want to be able to top it up when at a circuit and have the pump pressurise on demand. It needs to be a decent pressure, otherwise the water won`t atomise and will be less efficient.
I had a kit installed in past on my A3 It has reduced inlet temps ut has also robbed power! This was down to the fact that i did not want ignition timing adjusting as i was on oem management and was not practical to keep changing maps if i was not running wmi I guess for you guys with standalone its not an issue But beware claims that it reduces EGT-s as i could not get my EGT-s down
I wasn't planning on using it to lower egts. Interesting you say it robbed power. I wasn't aware of that. Prawn never mentioned it.
Are you pushing your engine in an area where it is experiencing PI to det? Maybe due to high air charge temps? Perhaps you have wound your turbo to the max and it is sneezing out heat and you need to cut back timing. This is where water injection will help. Of course it is useless if the above is not happening or if you are not prepared to adjust the engine calibration to make use of the extra density beyond nominal. Density of lack of, is taken care of via G42 in the inlet manifold if calibrated. The methanol part is like an antifreeze to stop corrosion.
Nope, not at all Nah, not an issue at all. I am not having that issue, as i said, it was to aid cooling after LONG areas ot WOT on 30+ Ambient temp trackdays. Kesselchen at the Nurburgring is a prime example. You see more Turbo cars broken down at the top of that hill than anywhere else on the circuit. I`m not changing the map, if the wmi fails, I`ll then be in an unsafe situation. Prawn has not modified his calibration to take advantage of the wmi, but he uses it for safety, to keep charge temps cooler on track. Are you suggesting there is no safety benefit from reducing charge temps by the addition of wmi, unless the calibration is tweaked to benefit ?
I am not trying to be patronising so please bear with me. In the 30 years I have been into this car scene I seldom do internet research and never add aftermarket trends to a powertrain unless there is justification, which could be from an attribute benefit and then cost or worse yet a patch to a cock up lol. So you do not have an issue with Pi induced DET but have noticed rising charge temps while tracking the car at the Kesselchen, which is an uphill part on the ring. So what actions have been calibrated into the engine calibration to correct for the increasing lack of density ( induced by both lower ambient pressure and air charge heat)? If that is calibrated to compensate for the increased charge temps, my comment for water injection use applies (other than the use of a more efficient turbo or a WACC). As a reference, you would be hard pressed to find a OEM boosted vehicle blowing at the top of Kesselchen due to the lack of water injection, certainly not at mild ambients of 30 deg. That is also the temperature of some export markets and they are fine in that environment too! So density is nominal and your engine is happy however you apply water injection, which in turn increases density to beyond normal. What actions should be taken to unsure you use the benefit? If you believe the water injection addition will fail one day, why not design some fail safe logic that reverts to the standard density correction and cal. When one looks at the typcialcalibration actions for such an odd scenario, what makes you think the calibration will be unsafe? Nick cannot easily do that on the fly with his OE system but you can Safety in what respect? PI or DET? You just said you do not have that problem? My comments relate to air charge density. Message to all reading in, this is all discussion not a debate . Feel free to put any of us right!
I fully understand . It`s why I started this thread, rather than just building a kit and fitting it, only to find it was a waste of time. There is a huge amount of knowledge on here and when searching, i realised there wasn`t a decent thread on wmi Eddie, I think we`re approaching this from different perspectives. OEM boosted vehicles have knock control and far better protection than a garage built ABF 16VT with a Megasquirt 1 ECU controlling it lol That`s one of the reasons I`m fitting the AEM Failsafe gauge, to get some automatic protection apart from the timing retardation that is all Megasquirt can offer with high IAT`s. I am already addressing the underbonnet temps with the bonnet vent. What I`m looking into wmi for is to add MORE protection / safety. Where an OEM would say "Right, that`s safe now, we need to save money, so stop there", this is a home built track car that gets used exclusively on circuit. I have addressed all the main areas I could when I built the engine, from fresh bearings to new rings in a honed block. Large radiator, large oil cooler, large intercooler, ducted air through those coolers. Large injectors, non agressive timing map etc etc etc. However, that doesn`t mean I have to stop there. Imagine this scenario. I`m at the Nurburgring in summers a glorious summers day, temp well into the 30`s. I`ve just done a couple of flying laps and I see a GT3 up ahead and fancy a play. I switch to `high boost` using MSDroid on my dashboard and start to enjoy an entertaining tussle around the track. Halfway up kesselchen, I see IAT`s are starting to rise and Megasquirt pulls timing. Not because anything is WRONG, but simply because I`ve put more stress on the Turbo than usual, both from increasing the boost and also from long WOT sections of the track. Having the option to press a button and get those temps back to normal levels is exactly the scenario I see wmi being deployed in my setup. I assume you mean by taking actions that I`d add timing to take advantage of the cooler charge air ? I don`t change the timing on a cold trackday and see no reason to do so with wmi. This isn`t a way of chasing more power. I have enough of that already, it`s a way of further reducing inlet temps and all the benefits that are associated with low inlet temps I can ? Oh ! I`d rather run with IAT`s at 20 Degrees C instead of 40. It just makes everything more efficient. Why WOULDN`T I want that ? Message to all reading in, this is all discussion not a debate . Feel free to put any of us right!
Nige what's the difference between discussion and debate ? I've had a lie in and my brains not upto speed yet lol EVER lol
I have run an aquamist 2-point system on my Polo for years, and put many liters of methanol/water through it. One pre-intercooler, one post TB. I have a large intercooler for the mass flow out the turbo, and generally no issues with high inlet temps (I would say with anything heavily boosted you're doing well if you're +20'C over ambient at any stage in the inlet). The only performance advantage that is tangible, comes from the ability to increase spark angle (or boost pressure for a given spark angle) as you've increased the headroom before det. In my Polo this is worth 3-4' of spark, which on a 2v/cyl engine running 9.3:1 CR and over 20psi of boost, is worth having! It has been calibrated with aquamist active, for track driving I found I top up the 'mist more frequently than fuel, but a larger tank size would sort that (currently 1 litre). Nige- for your setup to work (Megasquirt reducing timing retard due to consistently lower IAT) then you will have to lower the air temp before the sensor (obviously) so a pre-intercooler injector. This is based on my assumption megasquirt isn't retarding due to knock. You can do some fairly noddy calcs to work out your mass flow, how much you need to lower the IAT by (and what energy this would take), and thus how much water/methanol you need to inject to do this- and the latent heat of evaporation of various ratios (water cheaper then meth!), one of the WMI manufacturers had something on their site IIRC. Easiest solution is to increase base cooling (through ducting/more efficient cooler) rather than adding WMI- you'll find this lowers your average IAT far more than using WMI just on high-boost/WOT sections. Having both a well sized intercooler, and WMI is only of real benefit if you can increase engine output in my opinion, I don't mention durability as I don't think it as an attribute any non-OEM can quantify accurately, in which case there's several failure modes that could be attributed to a WMI install, that clearly you don't suffer from if you don't install it. Cheers Pete
Same difference. In the past, if you disagreed with some people, it became an argument where battle lines were drawn and they wouldn`t listen to other viewpoints. What Eddie is pointing out is that just because we aren`t agreeing 100% (we may end up doing so , doesn`t mean we can`t be rational adults about it I don`t like the whole pre-intercooler idea. Surely you`ll end up with some water collecting in the intercooler My IAT is in the plenum, so I could inject after IC, before TB I am already doing all I can to address the base cooling. I 100% agree that should always be the first option.
Some good guys adding to the discussion . You may not like it what Yoof is saying but it is simple physics. Water vapour will evaporate pre intercooler and further reduce the pre intercooler charge temp I will also clarify later some assumptions, I commonly here on the internet about the purpose of knock control in an OEM boosted car. The same system is also there in a NASP car as well.
But if you are WOT and spraying wm pre intercooler, then you lift off to brake so you get fully closed throttle, won`t that vapour just sit in the intercooler ?. There will be some atomised wm in the intercooler when you do so and it`ll have nowhere to go. If you are off throttle for a while, surely it`ll condense and sit in the bottom of the intercooler ?
I have no experience of using it but from what I have seen it is mainly used on very high boost applications. I would only use it if your going to take advantage of it (run high boost/map). More of a drag than track solution IMO. I think its normal to expect peaks and lows with your IAT on any track with/without water meth. Id be more tempted to invest in a knock detection system setup for your vehicle with warning light ?
Nige- I've never had an issue, I will dig out my jet size (0.4mm from memory at ~150psi??), the standard aquamist nozzles atomise fairly well (more due to injection pressure than any clever nozzle design). Also pre-intercooler compressor outlet temp is well in excess of 100'C (if you're nearing 180+'C then something isn't sized properly). Methanol (and water) have a lower boiling point than your compressor outlet temperature at WOT. So even if you did have a pool of methanol/water it wouldn't stay in a liquid state for long. In practice, you're able to safeguard against this with a few features: - Boost control switch to activate WMI (perhaps in sync with IAT - MS can drive channels based on calculations Eddie?) - Correct mechanical management of injector/nozzle size and injection pressure - Injection position I'll try to grab some picks of my setup for you if you're interested Cheers Pete
