high compression boost?
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Re: (wantboost)
Dude, race gas is simply not needed for 500+whp on pump. What is needed is ridiculously low compression with a turbo that is efficent at higher boost levels.
Lets just do a theoretical test using an online compression calculator. Lets use a stock bore GSR as our example shall we? We are going to assume that engine 1 and 2 are going to make the same exact powerband once full boost pressure is achieved.
Stroke: 3.43307087 inches. Bore=3.18897638 inches. VE=100
Engine 1 Comp=9:1 Engine 1 Boost Pressure=25psi.
Engine 2 Comp=8:1 Engine 2 Boost Pressure=30psi
Now calculate the compression ratios.
Engine 1=22.605442176870753 psi
Engine 2=22.285714285714285 psi
This is effectively saying that you can run 5psi more with 1 compression point loss and still have a lower compression ratio. Realistically it wouldnt take 5 extra psi to make up the approximate 20hp power loss from the 1 compression point loss so we are really saying you can make a TON more power when full boost arrives. I'm totally ignoring off boost throttle repsonse and power as 600whp I deem that as a race car and should be treated as so. I also dont believe in running 500+whp on pump, i was mearly illustrating the fact that lowering your compression ratio can allow you to make A LOT more power in the end before knock onsets.
Lets just do a theoretical test using an online compression calculator. Lets use a stock bore GSR as our example shall we? We are going to assume that engine 1 and 2 are going to make the same exact powerband once full boost pressure is achieved.
Stroke: 3.43307087 inches. Bore=3.18897638 inches. VE=100
Engine 1 Comp=9:1 Engine 1 Boost Pressure=25psi.
Engine 2 Comp=8:1 Engine 2 Boost Pressure=30psi
Now calculate the compression ratios.
Engine 1=22.605442176870753 psi
Engine 2=22.285714285714285 psi
This is effectively saying that you can run 5psi more with 1 compression point loss and still have a lower compression ratio. Realistically it wouldnt take 5 extra psi to make up the approximate 20hp power loss from the 1 compression point loss so we are really saying you can make a TON more power when full boost arrives. I'm totally ignoring off boost throttle repsonse and power as 600whp I deem that as a race car and should be treated as so. I also dont believe in running 500+whp on pump, i was mearly illustrating the fact that lowering your compression ratio can allow you to make A LOT more power in the end before knock onsets.
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Joined: Aug 2005
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From: Nashville, TN, United States
Re: (JDogg)
well my whole build idea just got a bunch of holes shot in it, but i am glad cause i rather it happen now but i send my motor off to get something done or order parts. cause like i said i dont wanna waste money but i do want hte best parts out there and to get the most out of my motor.
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Re: (JDogg)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDogg »</TD></TR><TR><TD CLASS="quote">off boost dosnt change when you change compression... 
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Your throttle response and power doesnt change when you lower your compression? What are you talking about? If that was the case we would all run 1:1 compression engines on 3 octane gas.
I didnt talk about spool time. Spool time wont change much at all. 20psi vs 20psi they should both come around the same rpm as compression has very little to do with spool time. If anything I've been reading lower compression spools SLIGHTLY faster due to the exhaust temps being elevated. I stress SLIGHTLY. I'll forgive you jumping down my throat prematurely and blame it on a long day
</TD></TR></TABLE>Your throttle response and power doesnt change when you lower your compression? What are you talking about? If that was the case we would all run 1:1 compression engines on 3 octane gas.
I didnt talk about spool time. Spool time wont change much at all. 20psi vs 20psi they should both come around the same rpm as compression has very little to do with spool time. If anything I've been reading lower compression spools SLIGHTLY faster due to the exhaust temps being elevated. I stress SLIGHTLY. I'll forgive you jumping down my throat prematurely and blame it on a long day
Honda-Tech Member
Joined: Sep 2003
Posts: 5,072
Likes: 2
From: Raleigh, NC
Re: (RedlineKustomz)
you can change ex temps very easliy with timing... its all in the tune.
there is a point of deminishing returns when you start lowering compression... most of the time i use the lowest that mechanicly possible (ie, the piston gets too thin etc..)
there is a point of deminishing returns when you start lowering compression... most of the time i use the lowest that mechanicly possible (ie, the piston gets too thin etc..)
Thread Starter
Joined: May 2005
Posts: 9
Likes: 0
From: Rex, GA, USA
Well, I want to shoot for right around 300whp, give or take 20 each way, but this is a single cam motor, too, and that needs to be kept in mind. I have noticed that some of you guys are making crazy power on d16s though.
My turbo is a Garrett T3/T4- 50 trim compressor, P-Trim 1.15 a/r(huge, I wanna swap for a smaller one) turbine. Like mentioned before, I would like to boost around 2500-3000 rpm. I have a friend that's making peak boost from 2500-8000 RPMs on a B18c1 with a GT28RS, but I doubt I'll see that kind of power band, though it would be nice.
My turbo is a Garrett T3/T4- 50 trim compressor, P-Trim 1.15 a/r(huge, I wanna swap for a smaller one) turbine. Like mentioned before, I would like to boost around 2500-3000 rpm. I have a friend that's making peak boost from 2500-8000 RPMs on a B18c1 with a GT28RS, but I doubt I'll see that kind of power band, though it would be nice.
Re: (RedlineKustomz)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RedlineKustomz »</TD></TR><TR><TD CLASS="quote">hard to get parts? So your saying its possible for you but not me , cause u have hard to get parts that Icant get my hands on? and how about did you receive these sponsors?
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You can get your hands on it (the turbo part, anyway...) I created wantboost's turbo and can give you a hand. Its just that for the efficieny you're looking for, lowering the compression even more makes the turbo just do more work. If this is strictly a Drag car, and will not see the street, that is one thing, You'll find race gas.but face it.. You're in lower KY, in an area in which premium octane is only 91. (NE,MO,KS,IA, ) are mainly the other states that have this problem as well. to get over 550 on pump gas is not realistic at all. Now about 440whp to 450, THAT's actually possible, but it is safest to get at least some octane booster so it bumps it up to about 93 (BP stations in your area have about 92 octane, but that's as good as it gets)
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You can get your hands on it (the turbo part, anyway...) I created wantboost's turbo and can give you a hand. Its just that for the efficieny you're looking for, lowering the compression even more makes the turbo just do more work. If this is strictly a Drag car, and will not see the street, that is one thing, You'll find race gas.but face it.. You're in lower KY, in an area in which premium octane is only 91. (NE,MO,KS,IA, ) are mainly the other states that have this problem as well. to get over 550 on pump gas is not realistic at all. Now about 440whp to 450, THAT's actually possible, but it is safest to get at least some octane booster so it bumps it up to about 93 (BP stations in your area have about 92 octane, but that's as good as it gets)
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Joined: Aug 2005
Posts: 1,734
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From: Nashville, TN, United States
Re: (TheShodan)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dday00si »</TD></TR><TR><TD CLASS="quote">try the cr calculator
i'm still figuring mine i'm running ls/vtec with stock bore 81mm cp pistons
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Are you talkin about the one this?
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by alsofood »</TD></TR><TR><TD CLASS="quote">compression calculator.</TD></TR></TABLE>
i'm still figuring mine i'm running ls/vtec with stock bore 81mm cp pistons
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Are you talkin about the one this?
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by alsofood »</TD></TR><TR><TD CLASS="quote">compression calculator.</TD></TR></TABLE>
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Joined: Aug 2005
Posts: 1,734
Likes: 0
From: Nashville, TN, United States
Re: (RedlineKustomz)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TheShodan »</TD></TR><TR><TD CLASS="quote">
You can get your hands on it (the turbo part, anyway...) I created wantboost's turbo and can give you a hand. Its just that for the efficieny you're looking for, lowering the compression even more makes the turbo just do more work. If this is strictly a Drag car, and will not see the street, that is one thing, You'll find race gas.but face it.. You're in lower KY, in an area in which premium octane is only 91. (NE,MO,KS,IA, ) are mainly the other states that have this problem as well. to get over 550 on pump gas is not realistic at all. Now about 440whp to 450, THAT's actually possible, but it is safest to get at least some octane booster so it bumps it up to about 93 (BP stations in your area have about 92 octane, but that's as good as it gets)</TD></TR></TABLE>
You know people say stuff like..."Dude, race gas is simply not needed for 500+whp on pump. What is needed is ridiculously low compression with a turbo that is efficent at higher boost levels.-alsofood" Then you and wantboost tell me its way out of my reach on pump gas? I would love to just have 500whp or as close as possible, I aint calling anyone a liar but can someone explain why some say its possible and others dont? Thanks
You can get your hands on it (the turbo part, anyway...) I created wantboost's turbo and can give you a hand. Its just that for the efficieny you're looking for, lowering the compression even more makes the turbo just do more work. If this is strictly a Drag car, and will not see the street, that is one thing, You'll find race gas.but face it.. You're in lower KY, in an area in which premium octane is only 91. (NE,MO,KS,IA, ) are mainly the other states that have this problem as well. to get over 550 on pump gas is not realistic at all. Now about 440whp to 450, THAT's actually possible, but it is safest to get at least some octane booster so it bumps it up to about 93 (BP stations in your area have about 92 octane, but that's as good as it gets)</TD></TR></TABLE>
You know people say stuff like..."Dude, race gas is simply not needed for 500+whp on pump. What is needed is ridiculously low compression with a turbo that is efficent at higher boost levels.-alsofood" Then you and wantboost tell me its way out of my reach on pump gas? I would love to just have 500whp or as close as possible, I aint calling anyone a liar but can someone explain why some say its possible and others dont? Thanks
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Re: (TheShodan)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TheShodan »</TD></TR><TR><TD CLASS="quote">
You can get your hands on it (the turbo part, anyway...) I created wantboost's turbo and can give you a hand. Its just that for the efficieny you're looking for, lowering the compression even more makes the turbo just do more work. If this is strictly a Drag car, and will not see the street, that is one thing, You'll find race gas.but face it.. You're in lower KY, in an area in which premium octane is only 91. (NE,MO,KS,IA, ) are mainly the other states that have this problem as well. to get over 550 on pump gas is not realistic at all. Now about 440whp to 450, THAT's actually possible, but it is safest to get at least some octane booster so it bumps it up to about 93 (BP stations in your area have about 92 octane, but that's as good as it gets)</TD></TR></TABLE>
I dont get honda-tech. Who cares if you spin the turbo faster? $500-1500 turbo compared to a $10k engine build! Lower compression+more boost=less stress on your engine. Tearing down an engine is far more labor intensive and costly than replacing a turbo. Not to mention these turbos are manufactured to spin at the rates described. Every product engineered as a FOS. I'm 100% sure comapnies like Garrett will not run a FOS lower than 3. So if it says the fastest it can spin is 150k rpm, its built to spin at 450k rpm. This is standard engineering.
Also, i strongly suggest not suggesting octane boosters that you buy from the automotive stores. They make you burn SIGNIFICANLY longer. Toluene is the only octane booster on the market I would suggest as pump gasoline is already some percentage toluene already. The burn will be significantly better.
If you want 500whp on 91 octane(not suggested AT ALL) you need to run low 8's compression or even high 7's. 9:1 wont be low enough.
You can get your hands on it (the turbo part, anyway...) I created wantboost's turbo and can give you a hand. Its just that for the efficieny you're looking for, lowering the compression even more makes the turbo just do more work. If this is strictly a Drag car, and will not see the street, that is one thing, You'll find race gas.but face it.. You're in lower KY, in an area in which premium octane is only 91. (NE,MO,KS,IA, ) are mainly the other states that have this problem as well. to get over 550 on pump gas is not realistic at all. Now about 440whp to 450, THAT's actually possible, but it is safest to get at least some octane booster so it bumps it up to about 93 (BP stations in your area have about 92 octane, but that's as good as it gets)</TD></TR></TABLE>
I dont get honda-tech. Who cares if you spin the turbo faster? $500-1500 turbo compared to a $10k engine build! Lower compression+more boost=less stress on your engine. Tearing down an engine is far more labor intensive and costly than replacing a turbo. Not to mention these turbos are manufactured to spin at the rates described. Every product engineered as a FOS. I'm 100% sure comapnies like Garrett will not run a FOS lower than 3. So if it says the fastest it can spin is 150k rpm, its built to spin at 450k rpm. This is standard engineering.
Also, i strongly suggest not suggesting octane boosters that you buy from the automotive stores. They make you burn SIGNIFICANLY longer. Toluene is the only octane booster on the market I would suggest as pump gasoline is already some percentage toluene already. The burn will be significantly better.
If you want 500whp on 91 octane(not suggested AT ALL) you need to run low 8's compression or even high 7's. 9:1 wont be low enough.