Show full size 924Board.org
Discussion Forum of 924.org
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
 Technical FAQ924 FAQ (Technical)   Technical924 Technical Section   Jump to 924.org924.org   Jump to PCA 924 Registry924 Registry

Stage Next...
Goto page Previous  1, 2, 3, 4, 5, 6, 7, 8, 9
 
Post new topic   Reply to topic    924Board.org Forum Index -> Performance Upgrades
View previous topic :: View next topic  
Author Message
kondzi  



Joined: 02 Jul 2018
Posts: 52
Location: MZ/Poland/EU

PostPosted: Fri Jul 20, 2018 9:09 am    Post subject: Reply with quote

Go to a junk yard, find a small Ford, like Escort from '90 and grab EDIS4 module, VR sensor and coil pack.

I've installed such setup in my friend's rally Escort MK2 some time ago and it gives you all you need plus some safety.
https://www.youtube.com/watch?v=CCEfkHfCjHY

You need to fit in a 36-1 trigger wheel somewhere though. This may or may not be tricky. My fiend's Escort uses a trigger wheel cut out of 0.7mm sheet of metal and bent teeth

The good thing is EDIS will run your ignition in limp mode even without MegaSquirt! So if something goes wrong with wiring or so, worst case scenario - you're running at 10 deg BTDC fixed. That's it.

I'm really a big fan of EDIS. Coil pack for 4 cylinder engine is basically 2 coils and EDIS is running it as wasted spark setup.

There's your answer to Spark Management. And you can get it running for about 20-30 bucks or less if you're lucky!
_________________
---
Konrad

'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded)
'74 Ford Capri 1.3 (factory specs)
Back to top
View user's profile Send private message
Noahs944  



Joined: 08 Dec 2015
Posts: 726
Location: Calgary, Alberta, Canada

PostPosted: Mon Jul 23, 2018 5:20 am    Post subject: Reply with quote

"I haven't messed with the MAT sensor yet.. I stopped when I couldn't find a NPT bung to weld on in my parts piles.. "

Heres what I did:get the approprate tap, research the recommended drill bit size. take 3-4 flat washers & stack them, weld them all to the pipe. Drill centres & tap for ndt. You just made your own bung.
Back to top
View user's profile Send private message
Fasteddie313  



Joined: 29 Sep 2013
Posts: 1561
Location: MI

PostPosted: Mon Jul 23, 2018 9:50 am    Post subject: Reply with quote

For water injection I see it recommended to spray about 10-15% water to fuel..

I'll estimate my fuel flow based on estimated HP.. That should be super accurate..
Given Horsepower x .50 lb fuel/hp = lbs of fuel for given horsepower

Stock boost is about 150 HP so 75 blhr of fuel = 7.5 lb/hr water
Hp - fuel - water 10% - water 15%
150 - 75 - 7.5 - 11.25
200 - 100 - 10 - 15
250 - 125 - 12.5 - 18.75
300 - 150 - 15 - 22.5
350 - 175 - 17.5 - 26.25
400 - 200 - 20 - 30

I have the 25 lb/hr fuel injector.. So at 100% duty cycle it would be good for 350-400HP..

to control the injector to keep the water injection within recommended range..

HP - 25lb/hr water injector duty % @12.5 % water/fuel - boost psi
150 - 37.5 - 6psi
200 - 50 - 10.5psi
250 - 62.5 - 15psi
300 - 75 - 20psi
350 - 87.5 - 25psi
400 - 100 - 30psi

Sure for peak HP RPM but what about RPM?
Well with less RPM as boost comes on and the engine goes through peak torque/peak DET sensitivity water % would be a bit higher toward 15% or so trailing down to around 12.5% high in the RPMs where the engine crosses peak HP?
Eh? Wishful thinking?

I think spraying more water just doesn't help any more than 10-15% so a little more won't hurt in the lower RPM area maybe?

Meth systems often just shoot a straight shot, like a flat 50 shot of nitrous, when they are activated so I don't think precise targeting is all that important through RPM variation..

The best snow performance system maps it's spray from boost and fuel pressure so they don't even map for RPM.. We good..
https://sportcompactwarehouse.com/snow-sno-320-stage-3-boost-cooler-direct-injected-2d-map-progressive-water-methanol-injection-kit?gclid=CjwKCAjw1tDaBRAMEiwA0rYbSNOUeBi7nd9HK8EuHGCmDXiefqAoRmVAA9UC-eUaAZquQca83DJrwRoCp8UQAvD_BwE&gsID=p1369937&


So If I just tell the microsquirt to fire my water injector at the duty%/boost pressure map I just made it should work about right..

I think the MS is supposed to be able to fire off PWM signal like this on the Fidle wire but I don't know how to tell it to start firing 37.5 duty at 6psi boost and increase linerarly throught to 75%duty at 20psi of boost..
Hope that's possible..

Actually I probably want to start firing the injector at like 95KPA intake pressure/almost no vacuum/WOT before spool at maybe 15% duty or something because it is supposed to help the turbo spool earlier.. So get that sucker squirting before it starts spooling up..

Because I want to squirt it right into the suck side of the compressor..
Because it is supposed to do magic things like making the turbo spool faster AND as the water gassifies in the compressor it changes the friction/composition of the air or something to where it actually changes the compressor map of the turbo giving it a larger efficency range to higher boost..

Volvo says pre-compressor water injection shows signs of wear on the compressor wheel at 50,000-100,000 miles.. I think this is an OK price to pay..

Water in the IC.. I guess I will have to keep an eye on that but I don't imagine it being a huge deal..


Ofcorse the whole plan could fail in spectacular fashion but that's the fun part right?


For testing, I think I could most easily stick the injector inside my airbox, and spray horizontally over my air filter towards the AFM, and let it suck the water mist right through the AFM and into the compressor..

No, I don't really like the idea of spraying water into my CIS AFM but doing it a few times for testing isn't going to hurt it if I WD40 it up good afterwards so it won't rust..

I could eventually weld an injector bung into my pipe between the compressor and AFM if testing is successful, but that's hard work n stuff..

No Meth, just water..
Meth adds more det resistance with its octane but you have to tune it into your AFR, are supposed to, because adding more fuel makes you more rich, which I don't want to do, and water alone is still supposed to provide 50%-80% of the det resistance that adding meth does..

So if I tune it on water, it will be safer tuning incase I screw up, then when I think the tune is good, I can take away the water and listen for det on det cans..

If no det without water then good, it won't explode if it runs out of water, I can keep spraying water for the performance boost, and it sure as heck won't det with the water if it doesn't det without..
Shouldn't need any change to the tune with or without water until wayyy up there where the water would be the last line of defense against det, somewhere up over 20psi where raceboy says they become det limited rather than just power limited with the right tune..

I'll probably blow another head gasket by then anyway..
Word is I will blow this new OEM HG sometime but as long as it holds up until I get it tuned up to around 15psi I'll be happy with that..
I should put some good pistons in it then too..

Get me some good water pressure in the area and I might as well spray the exterior front of my IC while I'm at it..
_________________
80 Turbo - Slightly Modified
Back to top
View user's profile Send private message Yahoo Messenger
Carrera RSR  



Joined: 08 Jan 2010
Posts: 1602
Location: Somerset, UK

PostPosted: Mon Jul 23, 2018 10:00 pm    Post subject: Reply with quote

My limited knowledge of meth injection is to avoid on our cars. Meth does not increase bhp but allows you to keep the timing/boost/bhp you desire and protect you from detonation if the set up is too close to the danger zone? I have heard it also saps a little power in use?

Lets say you achieve 250bhp but it knocks. The choices are to back off timing and/or boost which loses you 20bhp and the motor is safer. But potentially chucking in a water/meth injection makes the engine less prone to knock on the same timing/boost set up and you retain say 10bhp, so final result is 240bhp, maybe back to 250bhp if you are lucky.

On big horsepower cars, the above simple maths would be different, but I am thinking more about our engines here not high hp boosted/big engined race/drag cars

Is it better to go with meth or put higher octane fuel/additive in the car when you drive it harder and get closer to its danger zone?

Happy to be re educated?
_________________
1980 931 - forged pistons, Piper cam, CGT turbo, 951 ducted FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife LSD
Now www.924board.org/viewtopic.php?t=34690
Then www.924board.org/viewtopic.php?t=31252
Back to top
View user's profile Send private message
Fasteddie313  



Joined: 29 Sep 2013
Posts: 1561
Location: MI

PostPosted: Tue Jul 24, 2018 4:19 am    Post subject: Reply with quote

Carrera RSR wrote:
My limited knowledge of meth injection is to avoid on our cars. Meth does not increase bhp but allows you to keep the timing/boost/bhp you desire and protect you from detonation if the set up is too close to the danger zone? I have heard it also saps a little power in use?

Lets say you achieve 250bhp but it knocks. The choices are to back off timing and/or boost which loses you 20bhp and the motor is safer. But potentially chucking in a water/meth injection makes the engine less prone to knock on the same timing/boost set up and you retain say 10bhp, so final result is 240bhp, maybe back to 250bhp if you are lucky.

On big horsepower cars, the above simple maths would be different, but I am thinking more about our engines here not high hp boosted/big engined race/drag cars

Is it better to go with meth or put higher octane fuel/additive in the car when you drive it harder and get closer to its danger zone?

Happy to be re educated?


Hey Carrera, nice reply..

I'm no fluid dynamics expert either and I do not doubt that adding a shot of water on the same tune would drop a few HP..

As you say, most people use water/meth injection so they can run a higher power tune where they would be detonating if they didn't have the water/meth injection..

What I'm talking about here is a little more obscure.. I'm talking about injecting water only, before the turbo, so the effects are a bit different..

Injecting water only you inject a lot less than with water/meth.. iirc it's about 10-15% fuel by weight for water only and something like 20-25% for water/meth..

When you inject meth you are injecting more fuel into the same amount of air.. So if you had a perfect AFR before you spray meth after you add meth your AFR will be richer, and for peak power you should pull some fuel out of your tune to get back to perfect AFRs..

That makes meth all complicated n stuff.. Water only, their is no extra fuel in it, so it doesn't effect your AFR, removes the complexity in tuning..

Water/meth injection also gives you the advantage of an octain increase where water only does not.. So water/meth adds more det resistance than just water..


The reasoning for injecting water, I think, is the same reasoning behind why they put so much nitrogen into NOS.. 2 parts nitrogen to 1 part oxygen..

Nitrogen, like water, is inert gas.. It doesn't burn..
It just sits there and absorbs heat..

In a non-scientific the way I understand it explanation, when you are on your compression stroke, when the piston comes up and compresses your charge it gets hotter.. Maybe its 100 degrees before you compress it and then 200 degrees after you compress it...
If you have stuffed so much air into the cylinder before compression (boost), then their is that much more to compress, so more heat, where this higher heat now can start to ignite the mixture just from the heat, and you get preignition and/or more likely detonation..


Before you compress the charge the thermal energy in the charge is already there, it is just in a larger space..
If you take all that thermal energy and compress it, it is now in a smaller space, so it is hotter all crammed together..

Water and nitrogen sit in there and give your charge more thermal density, which means that your charge can now absorb more thermal energy to reach the same tempature, or will reach a lower tempature with the same thermal energy added..

So in a nutshell before the water/nitrogen when we compressed our 100 degree charge it turned into a 200 degree charge..
When we add our inert material, water/nitrogen, and compress it, now it only goes from 100 degrees to 150 degrees, and helps you stay below the charges flashpoint when you compress it..

Follow?

All of that has been about compression in the cylinders on your compression stroke, but these effects are the same with any compression, so it works on your turbo compressor too if you inject it before the compresser..

So if you add water before the turbo one thing is that the IAT exiting the compressor is lower, because of all that inert material in your charge there gave all of that heat something to absorb into..

Since the iat exiting the turbo is lower, the charge is denser, so their is more charge there, to the point to where a compressor actually has a different map with wet air than cold air..

With wet air the efficency island of the compressor grows, so the same compressor is more efficient for the same boost, or you can run more boost at the same efficency, with wet air..


It is really supposed to help the MOST when you are trying to push the limits of your compressor, exactly like your compressor situation Carrera, so you are in the perfect position to take maximum advantage of pre-compressor water injection..
You might get a kick in the pants from a boost in your compressor efficency..


Also water going through the compressor, most of it flashes into gas, so you also get a little bit of evaporative cooling effect.. Because shit gets cold when it evaporates because it does mmkay..


Then through the intercooler..
So you put a charge through your intercooler that has a higher thermal energy density, the wet charge..
The intercooler can then pull more thermal energy out of your charge because it soaks in better..


Like if you ran 150 degree air through your intercooler VS 150 degree water and run a fan over the IC..

The fan is going to pull a lot more heat off of the water IC than the air IC because their is a lot more thermal energy in water than their is air..
But also ofcourse the air will have a higher temp drop through the IC than the water because it takes so much more energy transfer to cool down water than air..
Water holds a ton of heat energy..

"""""""
Acetone 223 BTU/LB
Benzene 168 BTU/LB (This would be a stand-in for gasoline and shows why running rich is a poor substitute for water injection)
Ethanol 364 BTU/LB
Methanol 473 BTU/LB
Water 970.4 BTU/LB (Yep, you read that right)
"""""""

That's why we can't really find anything much better than good old water to run in engine cooling systems, the radiator..
Water is the king of being able to absorb, hold, and transfer heat..


I don't KNOW about any of this, it's all just a bunch of theory to me and not a lot of hard evidence..

I bet if I rigged it up to a button to complete the injector circuit, and push the button in the middle of boost, then I could push the button and just feel if I lose power, gain power, or the difference is negligible..

That's the plan.. Rig it up simple, push the button, see what happens..


"On big horsepower cars, the above simple maths would be different, but I am thinking more about our engines here not high hp boosted/big engined race/drag cars"

Well, maybe I dream about running 2 bars of boost some day
I think it will eventually choke on how much exhaust it can spit out the exhaust valves..

Even if I lose 10-20 HP, I think water will be a nice little safety future when I start tuning from 15PSI up to 20PSI..

I'm going to try not to blow it up, hence the water idea and cautious tuning, but the way it is put together right now 20psi is the goal for real, no pipe dream 20PSI or whatever explodes first..

I think that is as far as I am going to go before I put in some serious pistons, and will put a MLS HG on it sometime around/before then too I'm sure..

I think my turbo is good for a healthy 20-23 PSI max, but it is not the final end all be all turbo and I will put a serious turbo in it some day too.. The turbo is a prototype and it gets bigger every time I mess with it too..

All of these turbos have just been cheap tests, when I get it how I want it I will put a $1k serious turbo on there.. Probably like cedric's turbo if not a K27 like morghans but with a billet wheel, maybe that hot side upgrade rennlist link I posted in cedrics thread.. Get my hands on a 6.10 turbine housing eventually..

Pistons, I think I will just make custom flat top pistons, low compression maybe 7.5-8:1 ..
Just simple flat cut pistons for the right wrist pin, at the right compression height, with a super thick and durable top, top ringlands plenty far down, best rings possible, strongest piston material even at the expense of a little piston slap when it's cold..

A $1k turbo and $5-700 pistons don't sound all that unreasonable anymore these days.. I can go get it if I want it..

Kicking around ideas on how I can run a separate tank for E85 and purge the system with unleaded when it's done running for the day..

People with Subarus are paying $20k for blocks as good as ours..

High HP? You should know I'm crazy by now..
_________________
80 Turbo - Slightly Modified
Back to top
View user's profile Send private message Yahoo Messenger
morghen  



Joined: 21 Jan 2005
Posts: 7908
Location: Romania

PostPosted: Tue Jul 24, 2018 6:20 am    Post subject: Reply with quote

You want to absorb some of the combustion heat into a wiff of water...weeeell...how much water do you really have to run to actually cool down a 700-900deg combustion by say 10deg?
Is it really worth it on low output applications like the 924 street engine?
_________________
red 924 and not red 924
Back to top
View user's profile Send private message Visit poster's website Yahoo Messenger MSN Messenger
CÚdric  



Joined: 27 Aug 2004
Posts: 1766
Location: Sweden

PostPosted: Wed Jul 25, 2018 6:54 am    Post subject: Reply with quote

Your posts are so massive i dont have time to respond to everything, even though i would. Water/meth or only water is very efficient for reducing peak temp in the combustion chamber, i think i have several papers on this subject at work. The phase shift from water to steam takes a lot of energy to perform, and thats where the reduced combustion temps comes from. If you are limited by EGT, as many of tuned cars are (if you measure it) its very efficient, combustion temps are reduced and the reduced knocking can make you use earlier ignition phasing, which reduces EGTs aswell. I would overdose to much, it will slow down the combustion unnecessary and you will lose some power. The trick with these kind of systems is to trust them, if you do and adapt the tuning lots can be done.

There are benefits of using water injection into a compressor, google it there are several papers describing the phenomenon:

http://www.esi.nagoya-u.ac.jp/h/isets07/Contents/Session03/1224Nguyen.pdf

http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1570625

Its more sensitive for overdosing and you can damage the turbo, to get maximum out of it you need smallest droplets as possible, for the compressor. Saab had this pre compressor injection system as a factory option, but i spoke to the guys who worked there back then and it seems mostly because they had such crappy water pumps. And they did have problems with compressor wheel erosion with time.

I looked long and hard at WI systems before i chose the FMIC, but i still have an eye for it if i want to push harder and i seems to get limited by knock or want much lower EGTs, but that will be furter on in the future.
_________________
┤80 924 Turbo
Back to top
View user's profile Send private message MSN Messenger
Fasteddie313  



Joined: 29 Sep 2013
Posts: 1561
Location: MI

PostPosted: Wed Jul 25, 2018 7:22 am    Post subject: Reply with quote

CÚdric wrote:
Your posts are so massive i dont have time to respond to everything


Yeah, I have to work on not getting too carried away like that..

Thanks for the advice and links. I will study them..
_________________
80 Turbo - Slightly Modified
Back to top
View user's profile Send private message Yahoo Messenger
Display posts from previous:   
Post new topic   Reply to topic    924Board.org Forum Index -> Performance Upgrades All times are GMT + 11 Hours
Goto page Previous  1, 2, 3, 4, 5, 6, 7, 8, 9
Page 9 of 9

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group