I am going to do a 3100 topend swap on my TSTE, but I am considering rebuilding the whole engine at the same time since I'm gonna be tearing it apart a little for the topend swap anyways. I am just wondering where I can get a rebuild kit, and where I can get some .030 overbore forged pistons.
I was also thinking of putting in slightly higher compression pistons (like maybe 9.5:1 or so). Raising the compression that little should help boost performance, especially with the stock turbo, but it shouldn't be too much to not be able to run boost. (or at least thats what I'm thinking) So, do you guys think that it would benefit me any to put in the higher compression pistons? And if so, where can I get the pistons? Can I use the Gen III pistons? Are the Gen III pistons going to be strong enough to handle the boost if they will work?
I'm not 100% sure that I'm gonna rebuild the engine, but I am considering all angles of modifying this car to see which route I want to take.
Thanks,
Shawn
no no no, DROP your compression!!! the 8.8 is really to high for boosting. drop it down to 8.2:1 and run 16lbs boost with bigger injectors and you will really wake up that 3.1. Just my thoughts.
-Jeff
Here is some very excellent reading on this particular subject matter:
http://www.sdsefi.com/techocta.htm
Quote from: gp90seno no no, DROP your compression!!! the 8.8 is really to high for boosting. drop it down to 8.2:1 and run 16lbs boost with bigger injectors and you will really wake up that 3.1. Just my thoughts.
-Jeff
Not with the stock turbo I won't!!! There is no way the stock turbo can run 16psi boost efficiently enough to benifit anyone. Since the stock turbo can only efficiently run ~12psi or so, raising the compression will help to get more out of the engine with the small turbocharger. With a larger turbocharger I would consider dropping the compression or just leaving it alone. I will probably leave it alone if I do rebuild the engine but I'm just considering my options. I realize that lower compression is better for boost, but when your power adder is at its limits you do the same things you would do to N/A engine to add more power.
Shawn
Quote from: dbtk2Quote from: gp90seno no no, DROP your compression!!! the 8.8 is really to high for boosting. drop it down to 8.2:1 and run 16lbs boost with bigger injectors and you will really wake up that 3.1. Just my thoughts.
-Jeff
Not with the stock turbo I won't!!! There is no way the stock turbo can run 16psi boost efficiently enough to benifit anyone. Since the stock turbo can only efficiently run ~12psi or so, raising the compression will help to get more out of the engine with the small turbocharger. With a larger turbocharger I would consider dropping the compression or just leaving it alone. I will probably leave it alone if I do rebuild the engine but I'm just considering my options. I realize that lower compression is better for boost, but when your power adder is at its limits you do the same things you would do to N/A engine to add more power.
Shawn
No Jeff is right. To lower the compression also allows running more timing/bringing the timing back up, like stated in the article tookycat showed you! 8.8 is not bad, 8.5 is better, but unless someone takes the time to test the detonation threshold of these heads and piston tops (THE key areas that effect this threshold), there is no one magic number that can be quoted, but lower it better as we can make up for it with more boost and more timing, both of which make more power, to a point! Too low a compression and non/boosted power (cruise etc) will drop some, not as much as the lower compression allows you to gain once pushing boost, its a good trade off!! And yes there are Hondas running high compression and high boost, but their heads and pistons are different than ours, but they still do and benifit from lowering the compression! You are correct in that a bigger turbo/higher boost will really benifit from a drop in compression, and this is as easy as some new gasket shims 8)
Jeff M
Don't you think installing thicker gaskets is a "workaround" and not the real solution, due to effecting the quench/squish region? I haven't tested it but that's my conclusion from what I've read. Although obviously it's a lot less work than getting custom pistons forged and installed.. :lol:
Quote from: TookyCatDon't you think installing thicker gaskets is a "workaround" and not the real solution, due to effecting the quench/squish region? I haven't tested it but that's my conclusion from what I've read. Although obviously it's a lot less work than getting custom pistons forged and installed.. :lol:
Yes, simplier and cheaper (for those tapped for funds fixing their TGP :lol: ) than new custom pistons. As for possible problem, 3 high performance companies sell these just for that purpose, Victor, FelPro and SCE (sp?). We are not talking a lot of space added here so these will have little effect on combustion cycles. Dropping the compression with the piston will lower it at TDC so either way, its somewhat futher from the combustion chamber :) . If you want to know some downside to worry about, (water passage) sealing a copper or stainless steel shim WAS a problem, which has now been address with the use of Permatec Copper Spray-a-Gasket 8)
Jeff M
Quotewhich has now been address with the use of Permatec Copper Spray-a-Gasket
That stuff is the shit!!! We use it on all neon head gaskets. It makes it so that a head that should be replaced (HORRIBLE corroding of the aluminum on the engine side, cheap owners) seals good.
Quote from: Jeff MNo Jeff is right. To lower the compression also allows running more timing/bringing the timing back up, like stated in the article tookycat showed you! 8.8 is not bad, 8.5 is better, but unless someone takes the time to test the detonation threshold of these heads and piston tops (THE key areas that effect this threshold), there is no one magic number that can be quoted, but lower it better as we can make up for it with more boost and more timing, both of which make more power, to a point! Too low a compression and non/boosted power (cruise etc) will drop some, not as much as the lower compression allows you to gain once pushing boost, its a good trade off!! And yes there are Hondas running high compression and high boost, but their heads and pistons are different than ours, but they still do and benifit from lowering the compression! You are correct in that a bigger turbo/higher boost will really benifit from a drop in compression, and this is as easy as some new gasket shims 8)
Jeff M
Yes, but
1) I have no way to control timing, it is computer controlled as I would hope you would know.
2) I don't know about this engine, but I know the L67's once they get to about 28-30 degrees timing they stop making more power, the power actually starts decreasing. (as it makes sense it would) And it has been found that 1 degree of timing on an L67 is only ~2hp. So that allows someone to add 30hp over stock (which is significant I know), but then what do they do after they are doing that and running M90 with the 2.6" pulley (the smallest pulley that has been found the be efficient enough to make sense)? They raise the compression up to 9.5 and sometimes even 10:1 from the stock 8.5:1. This allows them another way to gain power because they ran out of boost and timing. So thats why I'm thinking I would raise it.
Shawn
You know... I haven't looked at my chip in awhile, but I don't think the computer is able to use all the timing that's programmed into it. I don't know about Jeff's chip, but I still think there is more timing to be had. All you have to do is let the ECM use it by keeping k/R away. It will use as much as it can until k/r sticks it's ugly head out. All I know is if I was going to do something that major, I wouldn't think twice about a turbo upgrade, so why give your car crutches when you can teach it to walk/run on it's own, how it was meant too?
Quote from: god910All I know is if I was going to do something that major, I wouldn't think twice about a turbo upgrade, so why give your car crutches when you can teach it to walk/run on it's own, how it was meant too?
no doubt. don't you have to build a custom crossover anyway? the last thing i would do is make one with a little T25 flange on it.
joshua
Quote from: dbtk2Quote from: Jeff MNo Jeff is right. To lower the compression also allows running more timing/bringing the timing back up , like stated in the article tookycat showed you! 8.8 is not bad, 8.5 is better, but unless someone takes the time to test the detonation threshold of these heads and piston tops (THE key areas that effect this threshold), there is no one magic number that can be quoted, but lower it better as we can make up for it with more boost and more timing, both of which make more power, to a point! Too low a compression and non/boosted power (cruise etc) will drop some, not as much as the lower compression allows you to gain once pushing boost, its a good trade off!! And yes there are Hondas running high compression and high boost, but their heads and pistons are different than ours, but they still do and benifit from lowering the compression! You are correct in that a bigger turbo/higher boost will really benifit from a drop in compression, and this is as easy as some new gasket shims 8)
Jeff M
Quote from: dbtk2Yes, but
1) I have no way to control timing, it is computer controlled as I would hope you would know.Shawn
:roll: Ya, there is no manual timing adjustment, but this conversation was by your words changing the compression ratio :) (higher which you now know not to do :!: ). Higher or lower and you would still have to adjust the timing in the chip to match your idea here, and WAY more chip tuning to make the short runner 3100 setup work verses the chip you have for the long runner intake in the stock 3.1L of the TGP, and the cam upgrade to match the air flow pattern of the 3100 verses the 3.1L.
Quote from: dbtk22) I don't know about this engine, but I know the L67's once they get to about 28-30 degrees timing they stop making more power, the power actually starts decreasing. (as it makes sense it would) And it has been found that 1 degree of timing on an L67 is only ~2hp. So that allows someone to add 30hp over stock (which is significant I know), but then what do they do after they are doing that and running M90 with the 2.6" pulley (the smallest pulley that has been found the be efficient enough to make sense)? They raise the compression up to 9.5 and sometimes even 10:1 from the stock 8.5:1. This allows them another way to gain power because they ran out of boost and timing. So thats why I'm thinking I would raise it.
Shawn
First, in your mention of advancing the timing too much/loss of power is referred to Negative Brake Torque, where Peak Cylinder Pressures are occurring too soon relative the piston location, this goes for your engine and many others, though not alot of them can run 28 -30 degrees SA. With a stock TGP chip (fuel cut taking out, but stock timing of course) and with stock engine/turbo, you are detonation upwards of 10 degree knock retard at 10 psi of boost, more so as you go with higher boost (see blue letters above in my first quoted post), so lowering the compression ratio would allow more timing to be added somewhat, but this is all talking theoretical, colder air might be another answer from a larger more efficient turbo and/or intercooler upgrade. Next is superchargers get limited fast on their output as you state, unless you can get a bigger one and/or cool down the air more with an intercooler ($1,500 to $2,000 still?? :shock: ), turbos are different, many more turbo up-grade options (in theory yes, some custom pipe work, maybe). So turbos are easier, and requires the compression ratio to be dropped for most engines depending on your end goal with turbo size use/desired power levels, and this is NOT a compromise as a few here might be thinking or felt that they read differently, it is the norm much more than the exception. I still keep reading even on the latest and to be released/future turbo engines from the OEMs, as well as turbo upgrade kits, that all lower the compression ratio to allow the turbo to stuff the air in and make more power than a NA engine with a higher compression ratio, at least in theory, but if you spend a lot more time and money on custom parts and work, you can make a high hp NA engine, not as easy or as far with adding a turbo, never seen any Formula 1 with their 1.8L motors making 1,500 hp without a turbo :lol: :)
So, if you were asking me to elaborate or correct myself, there you go, which I assume is really driven by your thoughts of how the supercharger compares running on an engine verses a turbo application, or the upgrades you are thinking about, which on here of recently, turbo upgrades and tests are being done by quite a few, check those topics out as I plan to stay there instead :wink: .
Jeff M
I know a turbo upgrade would definately be the way to go, but as I said I am just exploring all of my options.
QuoteFirst, in your mention of advancing the timing too much/loss of power is referred to Negative Brake Torque, where Peak Cylinder Pressures are occurring too soon relative the piston location, this goes for your engine and many others, though not alot of them can run 28 -30 degrees SA.
Yes, I know that its torque being made too soon, but I saw no need to elaborate on that because I know you knew what I was talking about. (as you did because you explained it)
QuoteWith a stock TGP chip (fuel cut taking out, but stock timing of course) and with stock engine/turbo, you are detonation upwards of 10 degree knock retard at 10 psi of boost, more so as you go with higher boost, so lowering the compression ratio would allow more timing to be added somewhat, but this is all talking theoretical, colder air might be another answer from a larger more efficient turbo and/or intercooler upgrade.
How much KR does the stock TGP chip usually have with stock boost? I always run AT LEAST 93 octane gas, usually 94 octane and the car runs too good to seem like its getting KR. I know in my dads GTP or my moms SSEi when they get any KR you can feel it, especially if you go WOT at the bottom of 2nd or 3rd, the engine just bogs down. In my STE (or my dads TGP for that matter) I don't ever feel that. Obviously a larger turbo and/or a better intercooler is going to make more power because of the colder air but does it really make that much difference in timing advance. You are making it sound like the stock chip (and even yours for that matter) will just keep adding timing until they get KR. I know on the L67's the stock PCM will only give you 15 degrees timing advance (which yes is a lot of timing). After that you can turn the boost down as much as you want and open the intake and exhaust and put in a bigger cam and an intercooler and anything else you want to do, but the timing won't go higher than 15 degrees at WOT. Is that similar to the TGP chip?
QuoteNext is superchargers get limited fast on their output as you state, unless you can get a bigger one and/or cool down the air more with an intercooler ($1,500 to $2,000 still?? ), turbos are different, many more turbo up-grade options (in theory yes, some custom pipe work, maybe). So turbos are easier, and requires the compression ratio to be dropped for most engines depending on your end goal with turbo size use/desired power levels, and this is NOT a compromise as a few here might be thinking or felt that they read differently, it is the norm much more than the exception. I still keep reading even on the latest and to be released/future turbo engines from the OEMs, as well as turbo upgrade kits, that all lower the compression ratio to allow the turbo to stuff the air in and make more power than a NA engine with a higher compression ratio, at least in theory, but if you spend a lot more time and money on custom parts and work, you can make a high hp NA engine, not as easy or as far with adding a turbo, never seen any Formula 1 with their 1.8L motors making 1,500 hp without a turbo
Yes, superchargers do get limited on their output fast, but the M90 on the L67 will go much further than the T25 joke of a turbo on the TGP's. But thats mostly because much more efficient intercoolers are available for the M90 and it is on a bigger engine with many more aftermarket parts available. The cheapest intercooler you can get for the L67 is $499. It isn't the best, but for $499 you can't lose. My dad has the $1300 one (the second cheapest one out of 4) on his GTP and it works very well and he is the fastest stock cammed L67 (completely stock bottom end, stock cam, stock heads, the only thing that wasn't "bolt ons" were 1.9 rockers, valvesprings, and pushrods). The intercoolers are getting cheaper for them everyday. But yes, turbo's are much easier to deal with, especially upgrading them. It is crazy how a little exhaust work can do wonders on a turbo car also. It just seems like they really can't be that much different than Supercharged cars because they are essentially the same thing only not belt driven, but everyday I read different reasons why they are different. I appreciate that there are a few of you that know quite a bit about this stuff, so I don't waste my $ on something that isn't going to do anything, its just crazy how different it is than a blown car.
QuoteSo, if you were asking me to elaborate or correct myself, there you go, which I assume is really driven by your thoughts of how the supercharger compares running on an engine verses a turbo application, or the upgrades you are thinking about, which on here of recently, turbo upgrades and tests are being done by quite a few, check those topics out as I plan to stay there instead .
Thank you. As you can tell I am fairly new with turbochargers. I know quite a bit (at least IMO) about supercharged cars, but turbos are a completely different monster. I learn lots more every day about them thanks to you guys.
Shawn