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Originally posted by Rara:
Compression ratio? YOu think changing compression ratio is cost effective? Do you think its a little dial on the dash?
My compression ratio has already been changed once, I half expect to have to do something about it anyway even if I don't go FI. Is a gasket such a big deal??
Octane must come into this somewhere.
Originally posted by Rara:
On the high dynamic compression ratio of a forced induction engine, proper timing becomes critical, too much brings detonation, too little brings EGT's to hotter than the flames of hell.
And the degree of this problem is proportional to how much excess you're stuffing into it, right? So the more ambitious you are with your power goals, the tighter that squeeze would be, not so?
Originally posted by Rara:
If you are honestly that concerned about a given power level, you really shouldn't consider increasing the power level over stock. No, I am NOT kidding.
Great, you just invalidated most of the serious NA modders on CEG. Who limits themselves to 10% gains around here?
Originally posted by Rara:
For someone so concerned about durability of your trans, you don't seem to care about the life of your engine very much.
All I know is that people keep telling me that a tour ATX is way more at risk above 200 HP than a tour engine or tour MTX is. Are they wrong?
(I believe there was a recent article somewhere about a Focus project where they put on more and more boost with stock zetec internals until it finally blew up, and it got well up into the three hundreds.)
Besides, I just don't foresee wanting any more than 200. I might well be happy with 175, for that matter. Which means that this project is not going to justify the kinds of expense associated with a full balls-out turbo job.
Originally posted by Rara:
In all honesty, if what you want is more, and reliable power, sell your car and buy one that has more power stock. Your priorities are out of whack,
You don't know what my priorities actually are, or what my overall purpose with this is. You seem to be saying it's something nobody should even be interested in pursuing. That's not your call to make.
Originally posted by Rara:
...you are terribly concerned about the amount of hp to go through your trans, and are ready to sacrifice the life of your motor to do it.
Um, you just said I'm messing up my motor by LOWERING its power. That makes lots of sense.
It sounds like you would argue that there is no such thing as a legitimate forced-induction product that isn't intercooled. Nobody should ever use, say, an Eaton supercharger, or a non-cooled factory turbo. Is that your position?
Originally posted by Rara:
Quote:
Lots of people run single-digit amounts of boost without intercoolers and don't die of detonation, right?
Yup, and most of those throw in copius amounts of excess fuel to cool the intake charge (sort of like water injection). Most OEM's lean on this one heavily for factory forced induction vehicles; you should see the A/F curve for an 03 Cobra at WOT, its pretty fat, and that car even HAS an intercooler. But you can rest assured they are addressing the issue in some manner, even if it isn't the right way.
Well, this is genuine new information. Do factory turbos really run super-rich? They must pollute like hell if that's so...
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Originally posted by Paul Kienitz:
Well, this is genuine new information. Do factory turbos really run super-rich? They must pollute like hell if that's so...
My thunderbird peggs my A/F rich on WOT at 18psi...
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"Absolut Rara."
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Geez Paul, I hardly know where to start on this, you seem to have a kernel of knowledge that is fouled up in misunderstanding and misinformation. I'll try . . . Quote:
My compression ratio has already been changed once, I half expect to have to do something about it anyway even if I don't go FI. Is a gasket such a big deal??
And how much, dare I ask, was your CR changed by changing the gasket? Not too much I would venture. Further, changing gasket thickness enough to alter CR an appreciable amount is so the wrong way to do things its not even funny. On a forced induction engine, the HG often acts sort of like a fuse, when you go to a thicker gasket to reduce CR, you've just dropped the rating on your fuse, often to far below where it should be. Its begging for a blown head gasket. The proper way to change CR is typically with new pistons, and sometimes is acceptable to modify the head deck thickness or the combustion chamber to alter the CR, but such changes should only be even attempted by someone knowledgable, or someone willing to risk the entire engine for the sake of learning by trial and error.
Quote:
Octane must come into this somewhere.
Yeah, a little, but are YOU going to swing by the airport for AvGas every time you need a fillup? I think not. Depending on where you are in the country the max available octane at your local gas station is 91, 93 or 94. Even on 94, on my bone stock 5.0L the difference between stock timing and knocking can be as little as 5 degrees initial advance (10 deg base timing vs. 15 deg base timing) and becomes more critical on forced induction, and even more so on a non-intercooled setup.
You also seem to be completely missing the point that air charge temp plays just as important of a role as octane, if not more so.
Quote:
nd the degree of this problem is proportional to how much excess you're stuffing into it, right? So the more ambitious you are with your power goals, the tighter that squeeze would be, not so?
True, in some sense, but it really isn't the power goals its how you reach the power goals, and what steps you take to ensure things run correctly.
Quote:
Great, you just invalidated most of the serious NA modders on CEG. Who limits themselves to 10% gains around here?
Who exceeds 10% gains? not too many, and certainly none that don't make significant mods across the entire engine system. For the most part, the contour engines are not bottlenecked anywhere and require significant mods throughout the ENTIRE system to see major power gains. Its designed that way on purpose from the factory . . .
Quote:
All I know is that people keep telling me that a tour ATX is way more at risk above 200 HP than a tour engine or tour MTX is. Are they wrong?
So, what you are telling me, is you want to half-ass your upgrades? You are willing to pay to upgrade the engine, but not the transmission? And because you aren't willing to upgrade the transmission, you are willing to accept a poorly conceived forced induction system? Just because you can buy something, and it fits, doesn't mean its a good idea to use it.
Quote:
(I believe there was a recent article somewhere about a Focus project where they put on more and more boost with stock zetec internals until it finally blew up, and it got well up into the three hundreds.)
And your point is? Its not power loads that usually kill your motor. With a proper fuel and timing tune, you might be very surprised at how much power a particular engine can withstand for a short period of time. BFD, its the day to day stuff that's hard. if you don't design your street car system with some sort of cushion in its design for unexpected events, like a particularly hot day, or a mislabeled gas pump, or whatever, you will kill your engine, due to detonation or to high exhaust temps.
Quote:
Besides, I just don't foresee wanting any more than 200. I might well be happy with 175, for that matter. Which means that this project is not going to justify the kinds of expense associated with a full balls-out turbo job.
Who said anything about a balls-out turbo system? I'm talking about a properly designed one.
Quote:
You don't know what my priorities actually are, or what my overall purpose with this is. You seem to be saying it's something nobody should even be interested in pursuing. That's not your call to make.
No, I'm saying you are trying to do things backwards.
Quote:
Um, you just said I'm messing up my motor by LOWERING its power. That makes lots of sense.
No, I didn't, you apparently aren't paying very close attention. You are jumping all over the map with your comments, and none of them really tie together, except that you apparently want 200hp because you think yur transmission will explode the instant you exceed that, and you don't want to pay for an intercooler to get to that power level. I'm saying that an intercooler, even at a given power level, will make things much healthier for your engine, with increased cushion against detonation, and lower overall temps in the engine. Unless you are running ~5psi or less, which is almost pointless to go through the effort and money on a small displacement engine to setup up a turbo for that.
Quote:
It sounds like you would argue that there is no such thing as a legitimate forced-induction product that isn't intercooled. Nobody should ever use, say, an Eaton supercharger, or a non-cooled factory turbo. Is that your position?
Can you name any recent (and decent) OEM forced induction vehicle that doesn't use any form of intercooling? The last one I can think of went out of production in 1989 and was the Merkur XR4Ti, and at that was in desperate need of an intercooler, especially considering the other two applications of the same motor in fords line-up got one (the SVO mustang and the T-bird turbocoupe). IMHO, anything over 6psi in boost should seriously consider some form of charge cooling, and further, should require it, except in extreme cases with other mitigating circumstances.
Quote:
Well, this is genuine new information. Do factory turbos really run super-rich? They must pollute like hell if that's so...
Now, see, this sums up most of your posts and comments on this subject; This isn't new information. It is common knowledge amongst anyone with some reasonable familiarity of forced induction systems on internal combustion engines. Granted, some of the details and particular numbers, etc. may be up for debate, but the principles are sound and proven.
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Originally posted by Rara:
And how much, dare I ask, was your CR changed by changing the gasket? Not too much I would venture. Further, changing gasket thickness enough to alter CR an appreciable amount is so the wrong way to do things its not even funny.
My CR was changed by a warped head, which was shaved. I had understood that it was commonplace to lower it back down with a thick gasket. If this is a bad idea, maybe I should check further into this. Question: if a thick gasket is a likely failure point, does this apply even to no or low boost, or is it mainly a high boost problem?
Originally posted by Rara:
You also seem to be completely missing the point that air charge temp plays just as important of a role as octane, if not more so.
Where do you get that I missed it? I acknowledged it. I am just wondering if it is so important for low boost levels. A natural thing to wonder, since there are lots of low boost cars that don't do much about the issue.
Originally posted by Rara:
Who exceeds 10% gains? not too many, and certainly none that don't make significant mods across the entire engine system.
Not too many, perhaps, but enough. And all the ones in the zetec forums are still using stock internals. Are they wrong?
Originally posted by Rara:
So, what you are telling me, is you want to half-ass your upgrades?
Well I guess you could call any smaller upgrade "half-ass". That does not mean there's anything wrong with it. Yes, I want "half-ass" power upgrades, rather than a $10,000 drag racing setup.
Originally posted by Rara:
You are willing to pay to upgrade the engine, but not the transmission? And because you aren't willing to upgrade the transmission, you are willing to accept a poorly conceived forced induction system?
Well, if every un-intercooled compressor on the market is "poorly conceived", I guess I'm hardly alone in being "willing to accept" that.
Originally posted by Rara:
Just because you can buy something, and it fits, doesn't mean its a good idea to use it.
I'm not buying something that fits, but never mind, I'm not here to explain myself to your satisfaction.
Originally posted by Rara:
You are jumping all over the map with your comments, and none of them really tie together, except that you apparently want 200hp because you think yur transmission will explode the instant you exceed that,
Don't put words in my mouth.
Originally posted by Rara:
and you don't want to pay for an intercooler to get to that power level. I'm saying that an intercooler, even at a given power level, will make things much healthier for your engine, with increased cushion against detonation, and lower overall temps in the engine.
Yes, that's what you're saying, and I've heard you, and I'm sure it's true, and I don't think it has to be said any more times.
Let me put it this way. There exists one range of power, or of air charge density, at which it is perfectly safe to not worry about cooling. All NA engines should be in this range. There exists a higher range of power or density in which it is not safe to disregard cooling. Somewhere between the two is a transition from safe to unsafe. The location of this transition can presumably be expressed as a level of boost. The one point I'm not satisfied on -- on everything else I have no dispute with anything you've told me -- is whether this transition falls above or below the level of boost I'm interested in, which I estimate to be somewhere between 5 and 8 psi. You seem to be saying, so far, that any real-world boost application is always above that line. But lots of people drive such cars, so I have to wonder if there isn't a reasonably safe zone I can work in.
Originally posted by Rara:
Unless you are running ~5psi or less, which is almost pointless to go through the effort and money on a small displacement engine to setup up a turbo for that.
I think I mentioned that this is not a turbo. (And it'll probably be next year before I can start on it, so this is all preliminary.)
At this point you seem to be suggesting that the 5 PSI level might well be safe. That's helpful information if it's solid. I'm just speculating that maybe I can stretch it to 7-ish. Is that so unreasonable an idea? It seems to be right where you'd estimate the iffy area to be. So why not just give it a try, and if it won't tune into a good state, settle for a pound less.
Originally posted by Rara:
Quote:
Well, this is genuine new information. Do factory turbos really run super-rich? They must pollute like hell if that's so...
Now, see, this sums up most of your posts and comments on this subject; This isn't new information. It is common knowledge amongst anyone with some reasonable familiarity of forced induction systems on internal combustion engines.
I meant new in this discussion, Einstein. As in somebody finally said something that contributed a useful point instead of repeating what had already been said.
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Ok, so you are going to supercharge your engine and you plan on running around 5-8 psi. Sounds like a fun car  . So lets say you build your system, set it at 8psi and you dyno 175 whp. Good for you. What if it is only at 165? 155? 145?  Could happen. Then what? You need to run higher psi with a supercharger to reach your hp goals compared to a turbo. It could very well be possible with proper tuning. So how do you plan on tuning it? Standalone? Too expensive. Custom Superchip? If it works, awesome. You also need to beef up your fuel system a lot. Let's say you make it to 175. You do all your maintenence ahead of schedule, you baby your tranny. Then one day your friend (wife, kid, co-worker, fellow CEG'er) borrows your car, puts in some 87 octane...  Or you are trying to impress some chick next to you at the light... It's 120 in AZ and you need to fill up at "Joe's Discount Gazz" 100mi from the next station... "8psi seems ok, let's try 9..." That $800 you saved just went to replacing your blown motor. And you still have no intercooler. There is a difference between saving money and cutting corners. Saving money is good. Cutting corners is bad. If money is so tight, that you can't buy a intercooler, what happens when you blow the engine? I will build my first FI system when I can afford to build the system and buy a new motor. There is a reason that factory turbos have low compression AND intercoolers. And don't say "But it's not a turbo" because from the throttle body back, its all the same to your engine. Or just build the darn thing and see who's right. Can you afford to take that chance? 
Contour--It will make a master mechanic out of you!
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Originally posted by Oeneus:
Ok, so you are going to supercharge your engine and you plan on running around 5-8 psi. Sounds like a fun car . So lets say you build your system, set it at 8psi and you dyno 175 whp. Good for you. What if it is only at 165? 155? 145? Could happen.
Actually, 165 at the wheels would be quite decent if I've only got like 6 PSI. If it's only 145 I'll figure something might be wrong, or lame, and I'll have plenty of tinkering to keep me occupied. I probably won't go as high as 8 PSI.
Originally posted by Oeneus:
Then what? You need to run higher psi with a supercharger to reach your hp goals compared to a turbo.
I don't really have a goal of a specific horsepower level. I suspect that 175 is about the most I can shoot for, unless I do head work or other expensive things of that sort, which I doubt I will; the danger of ever reaching 200 is probably nonexistent.
My purpose is to test out an unconventional approach to forced induction. This approach does not involve the large power penalty of a belt-driven supercharger, so the gains per HP would be similar to a turbo.
Originally posted by Oeneus:
It could very well be possible with proper tuning. So how do you plan on tuning it? Standalone? Too expensive. Custom Superchip? If it works, awesome. You also need to beef up your fuel system a lot.
I am planning on a custom chip, because it's something I'd probably buy anyway even if I didn't do this project. And the other conversations here seem to indicate to me that the stock fuel system will work at this level.
Originally posted by Oeneus:
Let's say you make it to 175. You do all your maintenence ahead of schedule, you baby your tranny. Then one day your friend (wife, kid, co-worker, fellow CEG'er) borrows your car, puts in some 87 octane...
Or you are trying to impress some chick next to you at the light...
It's 120 in AZ and you need to fill up at "Joe's Discount Gazz" 100mi from the next station...
"8psi seems ok, let's try 9..."
That $800 you saved just went to replacing your blown motor. And you still have no intercooler.
Most of these situations are ones I feel comfortable being responsible for avoiding. And an intercooler might help these situations, but I bet even with an intercooler these situations would still be risky.
I do have to sometimes deal with remote 87-only gas stations... I've carried octane booser juice sometimes, but this doesn't do enough, maybe I need to stash a couple gallons of methanol or something.
Originally posted by Oeneus:
There is a difference between saving money and cutting corners. Saving money is good. Cutting corners is bad. If money is so tight, that you can't buy a intercooler, what happens when you blow the engine?
Actually, this engine has already blown once, stock. That's how I got into modding in the first place, in fact; I found CEG when looking for repair help, and got the infection. That particular failure shouldn't recur, the way we fixed it.
I know there's a risk, but it's something enough people successfully do that I don't think the risk is unacceptable. One has to be willing to take some risk to consider any FI project, right?
Originally posted by Oeneus:
I will build my first FI system when I can afford to build the system and buy a new motor. There is a reason that factory turbos have low compression AND intercoolers. And don't say "But it's not a turbo" because from the throttle body back, its all the same to your engine.
Or just build the darn thing and see who's right. Can you afford to take that chance?
Yes, I can.
Or maybe I'll monkey up some kinda simple air-to-air cooler that will do a partial job.
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Quote:
My purpose is to test out an unconventional approach to forced induction. This approach does not involve the large power penalty of a belt-driven supercharger, so the gains per HP would be similar to a turbo.
This is what I want to hear about, lol. I'm guessing you are referring to an electrically driven compressor, but I'll let you speak for yourself. . .
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Regardless of what you do, if you give yourself a large enough margin of error, then you will be fine . You should be able to find a good, cheap intercooler at the junkyard or on ebay. If you pipe it well and place it well, it should do a good job. Of course now you have to go through with your project so we can all see what happens  .
Contour--It will make a master mechanic out of you!
95 LX MTX Bolt-ons
95 Neon SOHC ATX
77 Dodge Powerwagon-more displacement than my Neon, Contour, and wife's Saturn---combined!
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Originally posted by Rara:
Quote:
My purpose is to test out an unconventional approach to forced induction. This approach does not involve the large power penalty of a belt-driven supercharger, so the gains per HP would be similar to a turbo.
This is what I want to hear about, lol. I'm guessing you are referring to an electrically driven compressor, but I'll let you speak for yourself. . .
Well, if I just mount one of these in the trunk and run a shaft to the front of the car... 
http://www.tukantrikestoreinc.com/f3615hp.htm
http://www.tukantrikestoreinc.com/f332530hp.htm
What sort of boost could you get with a 15hp or 25hp motor anyway
Hey, if you ripped off the little gas tank and cooling fins you could even put it where the battery was, it even weighs less -lol-
97 Contour SE MTX
K&N 3530, UR UDP, 19# Injectors, mystery mod, FMS wires, Fordchip.com chip, SVT: TB, Flywheel, clutch, exhaust
04 Grand Caravan SXT
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You guys are killing me with the post-quote-post format!
Former owner of '99 CSVT - Silver #222/2760
356/334 wHP/TQ at 10psi on pump gas!
See My Mods
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'06 Mazda5 Touring, 5spd,MTX, Black
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