V8 supercharged/carbed Mustang GT...

[xxxscimitarxxx]

My car is a candidate for meth/water injection

ive just bought the vehicle but havent seen it yet as its still in USA and coming to UK

good ole fashioned forced induction system....

carburettor >> roots supercharger @ 6lbs of boost>>302ci built motor....

but with no intercooler !!

apparently putting out 467bhp as is (I doubt that though apparently there is a dyno sheet) but that was running on a bit of race fuel (also apparently)

but for the sake of this enquiry....its putting out some good power somewhere around 400 bhp

my plans are not so much to be able to run more boost (though l want the option to up the boost to 9lbs) but for better quality cooled air to run normal fuel on present boost

soooooo.......meth/water

my guess is that l can inject between carb and blower using a plate....or place injectors through the intake manifold wall adjacent to intake runners

the question is what kit or if not kit then what system would be reccomended

Hope to hear from the forum soon

Dave

[Richard L]

Dave,

I need to think about this a bit which system will suit you best. There are a few systems on the market that come with a map sensor, As boost pressure increase over certain setting, the system starts to inject and pregressively increase the flow as the pump speeds up.

These systems are are relatively inexpensive, quite a few US companies make them.

As as aquamist is concerned, we cannot offer a kit for this car due to lack of onboard sensors such as map sensor, RPM etc. All our system is based on fuel injector duty cycle.

For sure, you car should benefit from water injection. Roots supercharger is not known for its efficiency so loss is normally translated into heat (hotter charge air).

[xxxscimitarxxx]

Sorry you cant sell me anything Richard but appreciate your interest....and what ever results which come from your thinking about it a bit will be very much appreciated.....

I have seen loads of water/meth kits for sale US ebay and the like....but the emphasis seems to be on the sale and not the best result that can be obtained....

l have come across one US online provider www.coolingmist.com whic looks like it has got what you propose.....but as lm new to this and all thay can say is ''yes we have lots of kits'' but they arent actually advising me of anything particular....''go on the forum and ask around'' is not the answer l was looking for

So if its not an imposition l would be most grateful for what ever the reuslts are of your bit of thought in respect of a package of bits or any thing else that may be of help....sorry l cant help you profit from that ...maybe another time and another car......'what can you do for a 1991 BMW E34 M5...with six chokes!

[Richard L]

I just thought we can offer you something based on boost only, you need to get a 2-bar map sensor (http://cgi.ebay.co.uk/ACURA-HONDA-FORD-GM-TURBO-MAP-SENSOR-2BAR-2-BAR-w-PLUG-/280613245115?pt=Race_Car_Parts&hash=item4155da50bb).

It is the HFS-2 or HFS-3, operates in MPS (manifold pressure sensor) mode. You can set the start point and it will be progressive with boost from this point on. You can set the flow increase per psi with the onboard "gain" trimmer.

The HFS-3 is the same as the HFS-3 but with a dash gauge to monitor flow.

The HFS-2/3 is PWM valve based, so you will have fast response and good dynamic range. Sorry I have forgotten the HFS-2/3 can do this.

Here is the link (http://www.aquamist.co.uk/HFS3/HFS3v2w1.pdf) to the user manual,

[Wayne in NZ]

Hi Dave.

You have almost exactly the same issues as me.
I have a carbed 68 camaro with a small roots blower, very similar set up to your car.
I have no doubt that your car would make pretty good power, as does mine. However the problem with the small roots blowers is that they are overdiven in relation to the crank.
With my car the blower is 2.4:1 overdriven to make about 7psi. This is mainly because I have very efficient heads and the engine flows very well.
I limit my engine Rpm to 5500RPM because of the high blower RPM. This is not a problem though as it has tonnes of tourque down low.
Still though at 5500RPM my blower is doing 13200RPM.
Even when driving about town, at 2500 RPM (about 60Mph) it is doing 6250Rpm.
Because of the high Rpm's the blowers can get pretty hot, hot intake air is no good. Hot AIT's mean you have to reduce timing to prevent detonation. Reduced timing means reduced power.
I have done everything I can to reduce the AIT. Sealed the intake to the cowl bonnet so it can only draw air from outside the engine bay and made phenolic spacers to go between the manifold and blower and the blower and carb.
The next thing is supplimentary injection.
I have thouroughly researched all the other ones as best I could by either asking the manufacurers about thier system of operation or checking out running systems here, ( some were a bit secretive though ) and from what I can determine the cheaper "preogressive" systems merely speed up and slow down the pump by varying the pump voltage.
Considering that the pump would need about 9Volts in order to have enough energy to create enough pressure to properly atomise the injectant at the "on" point and that they most likely run them past 12 Volts ( say 14Volts ), I felt that that was not a very true progessive method.
Because I am a predantic bugger and want to get the most out of a system I wanted to be able to begin injection while still in vacuum, as this is where most of your driving is done unless under heavy accelleration. I struggled to find a system that could do that.
That said, they are good products for what they are designed to do, I wanted better.
After many emails to Jeff at Howerton Engnineering I decided to fit the HSF-6 system from Aquamist.
I was going to use the '3 as it can be configured to run of an external MAP sensor. There is the added cost of the sensor and some mods to the unit so I decided to get the '6 which is designed to have an onboard MAP sensor ( I chose -1Bar to +1Bar). It also has other functions as well.
I have a B&M blower which is what it looks like you have and I have tapped the jet recepticles directly into the top of the blower case. One in front and one behind the carb adaptor. They sit pretty much under the carb bowls. I did this because I dont have clearance under the bonnet to fit a cheater plate under the carb.
So, yes it can be done.
There are some minor issues with injecting in vacuum however, as I am learning, but nothing that cant be overcome with a bit of cleverdickery.

In my opinion, the aquamist systems are the best true pregressive rate sytems available using PWM control. This effectively replicates a normal fuel injector's operation.
They have come from WRC beginnings where efficiency and reliability are first and foremost, not from supply and demand by petrolheads.

I hope this helps answer your question. Sorry about the rant.

Cheers

Wayne