Can the engine take the abuse of the SC?
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Joined: Feb 2001
Posts: 2,895
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From: You wish
I heard it was 5 psi ;-). But seriously, 6 psi would fit perfectly with the observed gains.
In terms of wear and abuse, there are several things to consider.
1. Additional cylinder pressure. Whatever you do to gain more power, you're usually increasing cylinder pressure. In the case of the Comptech kit, the additional 40% intake pressure probably corresponds to increases in peak cylinder pressure of 20-40% (I'm guessing, lots of variables, 40% more power does not mean 40% more peak cylinder pressure). The primary component which suffers from this is the rings. Because high revving Honda engines tend to run relatively low tension oil rings, these are often the first to wear out under boost. Compression and power will be fine, but oil consumption will increase till eventually it is an issue, creating an overly lean mixture or putting excessive combustion byproduct into the oil.
2. Heat. 40% more hp means at least 40% more heat. Under typical driving conditions, the stock Honda cooling system can probably handle this, but under severe conditions it will probably be on the edge. I doubt even Honda designs in 50% cooling reserve. Additional heat can do lots of bad things, but typically your oil will break down sooner and your chances of detonation can increase.
3. Detonation. More heat, more cylinder pressure, increased detonation potential. The F20C engine has a knock sensor, but that only kicks in once detonation has started - it's kind of a last resort safety net. Now, Honda created a pretty tough bottom end in the F20C, as Ldogdotcom mentioned. Lesser VTEC engines don't have forged pistons or rods, which resist detonation better than cast parts. However, the F20C does share a weakness common to most Honda engines (save for the H22A4, the B20B/Z and perhaps the NSX engine) - an open deck block. This means the top of the cylinder sleeve is not connected to the top of the block. This prevents hotspots from developing and probably has manufacturing advantages (no need for a stress plate when boring the cylinders I would imagine). However, under high cylinder pressures (high boost or detonation) the sleeve can move around and may even break. Fortunately, under 10 psi this really isn't an issue. Detonation can also hammer the rod bearings, but it shouldn't be a major worry.
4. Additional crank snout forces. Driving the blower takes power and that comes off the crank pulley. I doubt the blower takes much more power than the alternator and A/C compressor combind at max load, so it probably isn't an issue, but it is additional stress on the end of the crank and more importantly the bearings.
Ultimately, the additional wear will depend on how often you are in boost. Just like an engine that spends more time at high revs will wear out sooner than the same engine that spends more time at low rpm. For a daily driver, I doubt that more than 5% of your total operating hours will be spent in boost. Thus, assuming none of the other issues I mentioend rear their heads, the overall lifetime of the engine should not be significantly affected (150k miles instead of 200k?). If you race the car, the wear could go up alot.
Recommendations? Good synthetic oil changed religiously every 3000 miles or maybe even more frequently. A good water temp gauge and maybe a radiator upgrade if you live in hot climates or race the car alot. You may never see the stock gauge move, but rest assured the temps will be higher (Honda gauges are worthless except to tell you when the car has gotten so hot that you better stop). A true oil cooler (mini radiator) might be nice too. And eventually an aftermarket fuel/timing management system would be nice to truly optimize the engine for power and durability.
UL
In terms of wear and abuse, there are several things to consider.
1. Additional cylinder pressure. Whatever you do to gain more power, you're usually increasing cylinder pressure. In the case of the Comptech kit, the additional 40% intake pressure probably corresponds to increases in peak cylinder pressure of 20-40% (I'm guessing, lots of variables, 40% more power does not mean 40% more peak cylinder pressure). The primary component which suffers from this is the rings. Because high revving Honda engines tend to run relatively low tension oil rings, these are often the first to wear out under boost. Compression and power will be fine, but oil consumption will increase till eventually it is an issue, creating an overly lean mixture or putting excessive combustion byproduct into the oil.
2. Heat. 40% more hp means at least 40% more heat. Under typical driving conditions, the stock Honda cooling system can probably handle this, but under severe conditions it will probably be on the edge. I doubt even Honda designs in 50% cooling reserve. Additional heat can do lots of bad things, but typically your oil will break down sooner and your chances of detonation can increase.
3. Detonation. More heat, more cylinder pressure, increased detonation potential. The F20C engine has a knock sensor, but that only kicks in once detonation has started - it's kind of a last resort safety net. Now, Honda created a pretty tough bottom end in the F20C, as Ldogdotcom mentioned. Lesser VTEC engines don't have forged pistons or rods, which resist detonation better than cast parts. However, the F20C does share a weakness common to most Honda engines (save for the H22A4, the B20B/Z and perhaps the NSX engine) - an open deck block. This means the top of the cylinder sleeve is not connected to the top of the block. This prevents hotspots from developing and probably has manufacturing advantages (no need for a stress plate when boring the cylinders I would imagine). However, under high cylinder pressures (high boost or detonation) the sleeve can move around and may even break. Fortunately, under 10 psi this really isn't an issue. Detonation can also hammer the rod bearings, but it shouldn't be a major worry.
4. Additional crank snout forces. Driving the blower takes power and that comes off the crank pulley. I doubt the blower takes much more power than the alternator and A/C compressor combind at max load, so it probably isn't an issue, but it is additional stress on the end of the crank and more importantly the bearings.
Ultimately, the additional wear will depend on how often you are in boost. Just like an engine that spends more time at high revs will wear out sooner than the same engine that spends more time at low rpm. For a daily driver, I doubt that more than 5% of your total operating hours will be spent in boost. Thus, assuming none of the other issues I mentioend rear their heads, the overall lifetime of the engine should not be significantly affected (150k miles instead of 200k?). If you race the car, the wear could go up alot.
Recommendations? Good synthetic oil changed religiously every 3000 miles or maybe even more frequently. A good water temp gauge and maybe a radiator upgrade if you live in hot climates or race the car alot. You may never see the stock gauge move, but rest assured the temps will be higher (Honda gauges are worthless except to tell you when the car has gotten so hot that you better stop). A true oil cooler (mini radiator) might be nice too. And eventually an aftermarket fuel/timing management system would be nice to truly optimize the engine for power and durability.
UL
Joined: Feb 2001
Posts: 7,414
Likes: 0
From: Toronto
UL,
Given all your Honda experience, what would you do for a NA buildup of the F20C? I know that for Integra's the DSR headwork was sworn by as well as Toga cams, and a good header/intake/exhaust/chip. What steps would you take, what parts would you use and what kind of gains would you expect?
Finally, do you plan to do any mods on your S2k?
Thanks,
Rob
Given all your Honda experience, what would you do for a NA buildup of the F20C? I know that for Integra's the DSR headwork was sworn by as well as Toga cams, and a good header/intake/exhaust/chip. What steps would you take, what parts would you use and what kind of gains would you expect?
Finally, do you plan to do any mods on your S2k?
Thanks,
Rob
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Joined: Feb 2001
Posts: 2,895
Likes: 1
From: You wish
2x6 - no, I wouldn't, at least not right now. For several reasons.
First, after working with a non-intercooled FI system, I've vowed to only use an intercooled system in the future. More power, more boost for a given engine and just all around safer.
Second, I want what I consider proper engine control before I do so. I could go to a Haltech, Electromotive, Motec, etc. right now, but I want to see what kind of plug and play systems come on the market.
Finally, while the power gain on the Comptech car is awesome, I'd like to see how other kits perform down lower in the rev range. A good turbo system should spool up sooner and provide more torque, as will an Eaton blower. Ultimately, a turbo system is probably ideal (easy to intercool, variable boost, etc.) although an intercooled Eaton or Whipple system would be awesome for the street (tire smoking 2000 rpm launches :-). Unfortunately, the guys who use these types of chargers don't seem to feel like bothering with intercoolers.
Oh yeah, as I think I've said, the F20C is such a fine piece of NA work, I'm tempted to leave it that way and see how much more power there is. But you'll never get 290 to the wheels NA.
UL
First, after working with a non-intercooled FI system, I've vowed to only use an intercooled system in the future. More power, more boost for a given engine and just all around safer.
Second, I want what I consider proper engine control before I do so. I could go to a Haltech, Electromotive, Motec, etc. right now, but I want to see what kind of plug and play systems come on the market.
Finally, while the power gain on the Comptech car is awesome, I'd like to see how other kits perform down lower in the rev range. A good turbo system should spool up sooner and provide more torque, as will an Eaton blower. Ultimately, a turbo system is probably ideal (easy to intercool, variable boost, etc.) although an intercooled Eaton or Whipple system would be awesome for the street (tire smoking 2000 rpm launches :-). Unfortunately, the guys who use these types of chargers don't seem to feel like bothering with intercoolers.
Oh yeah, as I think I've said, the F20C is such a fine piece of NA work, I'm tempted to leave it that way and see how much more power there is. But you'll never get 290 to the wheels NA.
UL
Registered User
Joined: Feb 2001
Posts: 2,895
Likes: 1
From: You wish
Rob,
From what I've seen so far, headwork and cams should work on the F20C. While the F20C comes with a 4 angle valve job from the factory, there is no hand work done on it. Bigger cams will almost certainly help out power, and Toda has impeccable credentials.
So far on my car I've got the Mugen header and the JR filter. I dyno'd the Mugen header and got zero gains in peak hp, but substantial torque gains from 3000-7000 rpm (and commensurate hp gains). I did my dyno immediately after installing the header, so the ECU may not have fully adapted. Others who gave the car a couple hundred miles seem to get a few hp up top. I didn't dyno the JR filter, but Richard Ming has.
If I stay NA, cams, along with adjustable cam sprockets, will be the big mod IMO. I'm really interested to see Richard Ming's AFC-VTEC install and tune and see how that helps. If it works, it'll make tuning a lot easier.
Exhaust wise, I think the stock system is pretty damn good. 2.5" on a 2.0 liter NA engine is big tubing. The only thing I'd really look for there is weight savings.
For headwork, well, I'll let someone else do the R&D first. I don't want to be the guinea pig.
UL
From what I've seen so far, headwork and cams should work on the F20C. While the F20C comes with a 4 angle valve job from the factory, there is no hand work done on it. Bigger cams will almost certainly help out power, and Toda has impeccable credentials.
So far on my car I've got the Mugen header and the JR filter. I dyno'd the Mugen header and got zero gains in peak hp, but substantial torque gains from 3000-7000 rpm (and commensurate hp gains). I did my dyno immediately after installing the header, so the ECU may not have fully adapted. Others who gave the car a couple hundred miles seem to get a few hp up top. I didn't dyno the JR filter, but Richard Ming has.
If I stay NA, cams, along with adjustable cam sprockets, will be the big mod IMO. I'm really interested to see Richard Ming's AFC-VTEC install and tune and see how that helps. If it works, it'll make tuning a lot easier.
Exhaust wise, I think the stock system is pretty damn good. 2.5" on a 2.0 liter NA engine is big tubing. The only thing I'd really look for there is weight savings.
For headwork, well, I'll let someone else do the R&D first. I don't want to be the guinea pig.
UL
