Yea, the motor pulls/sounds/feels great. It's really not laggy until you put a lot of boost on it. There is pleanty of power in all gears but I havn't been able to take advantage of 1st or 2nd because of my 2nd gear synchro being shot.
Guess my Dyno #'s
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Nice numbers dude, 500whp ain't no joke. 
it's double mine!
What exactly do you mean by "shot"?? It wont grip in 2nd gear... you can't snap 1st-2nd...???:icon_conf
it's double mine!hottscennessey said:
What exactly do you mean by "shot"?? It wont grip in 2nd gear... you can't snap 1st-2nd...???:icon_conf
IJ's right, it should be MUCH higher. I doubt holding boost to redline and revving it out would give me another 100+ WHP. IDK whats wrong..
well It stays in 2nd just fine, but I can't shift fast into 2nd.. I have to double-clutch to get it into 2nd.
The photo isn't very good. But it looks very rich. What are the numbers?
And the rough curve is often a sign of ignition break up.
Yea, it goes super rich towards redline.
keep in mind this car was street tuned and the AFRS were a pretty consistant 11.7 under boost.
on the chart..
3.5K RPM's is where it dips down to ~12:1
5k RPM's it goes lean towards 13:1
6K RPM it's back down to ~12:1 and getting richer towards redline.. down to about 10.5 revving to 7.2k RPM's
I agree, the rough curve is generally the ignition breakup.. but the boost flutters up and down when it falls off like it was, so that why I think the graph looks like that. Of course I'm not 100% positive about anything yet so I'm open to any and all ideas of why it's happening.
I'm gonna try and snag a better pic later if I can..
keep in mind this car was street tuned and the AFRS were a pretty consistant 11.7 under boost.
on the chart..
3.5K RPM's is where it dips down to ~12:1
5k RPM's it goes lean towards 13:1
6K RPM it's back down to ~12:1 and getting richer towards redline.. down to about 10.5 revving to 7.2k RPM's
I agree, the rough curve is generally the ignition breakup.. but the boost flutters up and down when it falls off like it was, so that why I think the graph looks like that. Of course I'm not 100% positive about anything yet so I'm open to any and all ideas of why it's happening.
I'm gonna try and snag a better pic later if I can..
No matter what boost controller you have you can only "reliably" double what the wastegate spring is worth. Usually you can get just barely more than double what the spring is worth, IE a 10psi spring would/should only be good for 22 +/- psi. We have experienced this many times.hottscennessey said:
What makes this happen is the pressure between the Exhaust valve and the turbo. Since the WG valve (itself) has a given surface area that area is acted upon by the pressure between the exhaust valve and the turbo (the volume trapped in the exhaust manifold). This seems to bear out, that most WG's have a 2/1 ratio between the area of the WG diaphragm and the area of the valve. Once the pressure in the exhaust manifold overcomes what the spring and the pressure in the WG diaphragm combined can hold your boost drops. Thats why you see 29 psi at lower RPM's. Your exhaust manifold pressure has not built enough pressure at lower RPM,s to push the WG valve open and for you to loose boost.
Also improperly designed WG returns contribute to a possible vacuum developed behind the WG valve and can actually help pull the WG valve open, but in this case we are talking about extreme velocities and very poor location of the WG return to the down pipe. That 18 inch rule that seems to be floating around seems to be a good rule of thumb. I wouldn't guess this is your problem.
You guys are overlooking it the benefit of latent heat of evaporization of water, and the effect cooling has on detonation suppression. Do what ever you want but I would mix Methanol and Water. You will get 1000 different opinions on the ratio, but for street use I have always used 50/50 but Im not anywhere near 29 psi. If I was doing dyno runs I would use race gas and H2o/Meth to make sure I was safe.hottscennessey said:
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Thanks ARZ, that makes perfect sense.. a 1 bar spring it is! I'm still doubting I'll see great results just by swapping springs tho.. there's gotta be something else.. but does it look like the wastegate situation could be causing the jagged dyno graph?
OH, and I'll definately have race gas in the tank next time.
OH, and I'll definately have race gas in the tank next time.
how many pulls? play with the timing on the dyno.. thats how you make power
As far as water goes.. imo it may evaporate and take away heat, but will make less power. For example on a high humidity day it will take away power. So why spray water in your engine? Plus the added octane from the extra methanol in the cyls will greatly increase the power and added knock suppression will to outweigh the heat absorbed though evaporation of the water.
Try back to back, I assume you will get greater power from straight meth.
Check on SF a guy logged his timing on a mkiv w/ an OBD 2 scan tool with 50/50 and straigh meth. More timing from straight meth = less detonation = better knock suppression. Thats my opinion.
As far as water goes.. imo it may evaporate and take away heat, but will make less power. For example on a high humidity day it will take away power. So why spray water in your engine? Plus the added octane from the extra methanol in the cyls will greatly increase the power and added knock suppression will to outweigh the heat absorbed though evaporation of the water.
Try back to back, I assume you will get greater power from straight meth.
Check on SF a guy logged his timing on a mkiv w/ an OBD 2 scan tool with 50/50 and straigh meth. More timing from straight meth = less detonation = better knock suppression. Thats my opinion.
I KNOW that is one of your issues, if you have others I couldn't say. If you search the boards you will see this all over the place. If you think about how fast a WG has to react all the time that could definitely be the cause of that jagged graph. Remember if the WG opens no matter what the reason you WILL loose power.hottscennessey said:
If your boost creeps down this is usually the cause. Your boost is at the upper limit of what the spring can handle.
If your boost creeps up, you usually don't have a big enough wastegate. And you are using a big turbo and trying to keep a relatively low boost pressure.
Agreed!!! Call the Dyno place and tell them YOU need to drive the car. And have a Camcorder running in the cockpit so you can see all the gauges and can play it back and watch it yourself. Also have a second camcorder going outside for your entertainment value. If they wont let you drive the car, tell them your going to find another dyno place. If you would have noticed that boost loss on the first pass you could have learned a bunch more from it. Also dont go to the dyno with the attitude "I gotta hit X HP!!!" that is a sure fire way to go home on a trailer.tissimo said:how many pulls? play with the timing on the dyno.. thats how you make power
According to my research water can be as much as 25% of the total amount of fuel, you have a long way to go before you loose power. It does evaporate and take away more heat, but it also consumes more thermal mass, (it makes the atmosphere more dense). What people forget is that fuels (methanol included) have very poor surface tension, when they are suspended in a vapor they avoid hot spots, embers, freshly ignited carbon deposits, even if they do make contact they have very little cooling effect. Water while suspended in a vapor does has a greater propensity for contacting items in the intake tract and combustion chamber due to its surface tension properties. This combined with the latent heat of evaporization, combine to actually quench hot spots not only in the combustion chamber, but also in the whole intake tract. The water vapor will continue to cool even after contact due to the velocities involved in the whole intake system. That being said, I have not researched the difference between straight Meth and H20/Meth, so check for yourself and go where the research leads you.tissimo said:
I live in AZ where the humidity is usually less than 10% so any amount of water in the atmosphere is a good thing.
People that discount H20 cooling don't ever think of the effect h20 has in the ladder half of the combustion event. In my research I found many examples of research supporting the greatest benefits from h2o injection came from the fact that once all of the available oxygen has been used up, radicals are generated and these radicals contribute to inconsistent flame fronts. These inconsistent flame fronts are less stable and more prone to detonation, bla bla bla. The initial burn of the combustion completely vaporizes the water and promotes an atmosphere that makes the available oxygen in the water ripe for the consumption of these radicals and drastically increases cylinder pressures at the ending portion of the combustion event. This latter release has been claimed to be responsible for more than 70% of the total energy in a combustion event. Not taking advantage of this 70% increase, at the perfect time in the combustion event (the very end, where it is much more likely to be past TDC) is leaving free HP on the the table. OK I use distilled water so it wasn't 100% free, but it sure is cheaper than Methanol.
I would only try this if you have a good reliable way of detecting knock and a way to shut it down quick. This right here, is the main reason I haven't experimented. And because Im cheap, 50/50 goes twice as far.tissimo said:
Thanks for sharing with all of us, anxiously awaiting results of your changes and second dyno pulls.
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I just wanted to update and say I was driving around today, so I decided to go to the dyno.
changes:
-turned up the gain
-checked for boost leaks
-set my timing much more aggressive
Today I only ran 25psi
533rwhp 497rwtq
the numbers are definately better, but still not perfect
The graph looks a whole lot better, it doesn't drop off after max power as it did before, it actually continued to make power until redline.
changes:
-turned up the gain
-checked for boost leaks
-set my timing much more aggressive
Today I only ran 25psi
533rwhp 497rwtq
the numbers are definately better, but still not perfect
The graph looks a whole lot better, it doesn't drop off after max power as it did before, it actually continued to make power until redline.
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