The effect has more to do with the conditions of the environment itself...hypothetically...because the charge temp is much higher post-compression, the introduction at this point has a significantly greater difference (differential) than the meth temp had it been introduced pre-compression. The differential should be what we are focusing on and not necessarily the mpemba effect...

Heh...this is one of those things where the people who wish for "perfection" are at odds with those who wish for "tried / true / habit". It's always a matter of specific goals...

I have a tendency to continually strive for increases in efficiency regardless if they are only worth .001% increase. To me that's still an increase...

For others...the trouble is not worth the .001%...

Different strokes for different folks...pre-compression injection does not bother me...primarily because I do not expect to be using any form of injection...and if I do, then if its important enough to me to get it post-compression...then thats my problem for being an ****-retentive engineer...

I would rather hear you say that you understand the science behind it...and "it's more trouble than what its worth right now"...or..."meh"...having an opinion and closing yourself off to the science is more what you do for a religion...

 

I would really like to try changing the position of my meth nozzle to see what difference it would make. Unfortunately I don't have the tools to do it.

Juan If your out there if you want to see how it would work prior to installing or ordering yours let me know.

That is an almunium piece I would need to drill into. If for some strange reason I decide not to leave the nozzle there. Would I need to order a whole new piece or is there a way to seal the hole?

 

You got me here...I have not crunched the numbers to determine what the theoretical gains would be...so I could not provide any tangible proof even from a theoretical perspective...if I get free time I'll see if I can do the crunching, and post my work for checking...

Heh...I wouldn't lolcat you into submission unless it was funny...

That and unlike the religious fanatics...I allow myself to be wrong and therefore do not see any good which could come from arguing in order to learn...kinda counter productive...I'd much rather learn something than to compare my mega-shlong online to someone else's...

 

cool

 

AAAHHHHH Yes that sounds simple. How much for the Bulk head fitting?

 

You sir have a serious addiction to speed...heh...good job...

Keep us posted...if at all possible remember to try to normalize your measurements...warm car, back to back as closely as possible data collection, etc...

While you may not be able to provide empirical data...a simple stopwatch and 5 runs should do it...

 

PM sent thanks!!!

Now by switching the nozzle placement I should see a decrease in temps should I also see a hp gain.

Is this some thing that merrits having a before and after dyno comparison?

 

This thread is great! Reading technical stuff that makes my head hurt is the biggest reason I joined this club in the first place.

 

Munche - Are you currently using your MAF for your air temps or do you have a temperature senson that is located behind your compressor? If not, how do you plan to see a difference in the intake temps before and after the location change?

 

isnt pre blower meth injection not so much a tuning issue as post blower?
I believe if I am not mistaken that the pre blower system can be used whenever you want too and the post blower system has to be tuned in and constant? Prehaps pettit wasnt looking for the top amount of power from this method but rather a more streetable version? I may be mistaken on this i am not sure.
Zoom the original Pettit system did not even have the maf mounted. The intake tube was smaller but it did not rely on the maf to run. As the system evolved people found that by mounting the maf they could get the dsc and traction control back amounf other things. The system as evolved to the point that now it is relying on the maf therefore a tuned air intake maf pipe is included.
The hose on the back of the SC is a vacuum hose---i was the one ,I believe, that used it to help correct the fast idle that a base map provides. This is only until i can get it tuned(i will be running the int x), the hoses have been rerouted to more of a oem configuation now. that s.c hose will go directly to the purge valve after tuning.
Great thread!
Vacuum for pettit is like this now I believe
1- the vdi and intake vaccums are the same as stock---have a manifold port to draw vacuum from
2- the s.c. blowoff valve/surge valve is also attached to a vacuum line.
3- the purge is attached to the line from the back of the s.c.
4- the power brake unit has a site of its on.
5- the mop and jet air have one ways and are on the intake.
the crankcase vent can the nascar style or you can t it into the intake if you want.
hope that is correct.
oscd

 

Ok sounds good. I will try that.

 

I have the sensor located behind the compressor.

 

This is the best thread we have had in quite a while. Keep it up

 

Ray how is my tuning going to be affected. With the flash and no tool out yet I can't retune on my own.

 

+1

 

Yes...the theory goes...you should see an increase in WHP simply by injecting post compression...

Does it merit a dyno? Not really, the data log should tell the story...would people like to SEE a dyno so they can stfu...of course...

The dyno would be interesting to have to correlate the data from the log to...but I would not really call it "necessary"...more like pr0n...

 

Ideally you would retune to take advantage of the new location...but IF the theory is correct...without a retune...the effect should "appear" as a denser charge than what the current tune is used to seeing...

 

Any sort of water or meth injection should be injected post turbo.

I like it as close to the TB as possible. Even though I have a 8 I have yet to tear into it as all my previous turbo experiences are on rx7's. I am now looking at the 8.

I would think the 8 would be very similar in aspects. The main reasoning for water/meth is the cooling and supression of detonation.

We were on the track w/ a 425 rwhp FD a month ago that was low on fuel. We ran a mix of 116 and 91. w/ water injection. Late in the day we went through 3 left handers. The car is still running the stock fuel tank so the pump is on the drivers side. Through those turns the pump was starved for fuel. We saw, felt, and heard detonation on all 3 times. This car is running 3mm seals which I don't feel are nessesary. Anyway to make the story shorter the motor has no damage to it. And runs perfect to this day.

I believe this correlates perfect to the Renesis engine. Because we are running 10:1 compression the water injection is a minimum requirement IMO. Water will cool the intake charge dramatically and allow more aggressive timing. (I will be installing one on a FD in the next 2 weeks and can data log more as I tuned this car.) Now obviously the more aggressive timing is optional.

As for meth. When you inject it postturbo I believe you will see cooler intake charges plus you will see lower a/f ratios. Meth should be chaning from a liquid to gas for when it is injected into the turbo. I cannot remember the temp it changes at but I will find it. Also when the change takes place is when the most cooling happens. This is why I believe it should be injected post turbo.

Hope that helps.

 

You guys are doing such a great job on this one that I feel no need to comment particularly.
My only concern is the use of a fitting in a silicone connector that is seeing pressure.
There might be no problem, but my preferred way of implementing this would utilize an aluminum charge tube so there would be no risks of leak or rupture.

 

Dude...there's E in the Eggnog...

 

I am getting confused between water.methanol and alcohol injections here. are we all talking about the same thing? Straight water injection vs blend vs methanol vs alcohol?
I understand the post turbo one but is the pre/post supercharger jury still out?
Are we speaking of tuning for higher octane also--or are we speaking of the cooling affect only?
Sorry to be a pita --old men get confused easily.
oscd

 

less dizzy now---thanks Charles
oscd

 

Oh - the other concern is the pressure of the injection kit.

A kit that is designed for atmosphere will not inject properly in boost.
The jets and pump need to be designed for positive pressure.
This is probably why Cam installs their system before the blower - its cheaper than doing it the right way.

 

Yar...the kit does have to do that...work in a positive pressure system...

What do the injectors run at?

 

MM, you're the man! That quote made my day

Kane - that chart gave me a headache!!! Why do people insist on sticking the independent variable on the y-axis.. Argh.. But thanks, that explains it (come to think of it, I've seen those charts before). Anyway, if you flip it over the right way it;s actually a logarithmic curve where for low values of air flow, a small change in air flow will give a large change in voltage. So on the low air flow end we have plenty of resolution to spare. This answers my question from the Esmeril thread too, thx guys...