9:5:1 cr too high for turbo???
12-01-2004, 07:36 PM
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9:5:1 cr too high for turbo???
hey whats up all, i have a 84mm sleeved b16a2 block with a b17 head, awaiting to be turboed. i had the sleeves honed for Arian pistons, which i am going to be buying here in a few days. so, is a b16 head and b17 head the same? the guy at Arias pistons is telling me they arent, but i know that they are both pr3 heads if i am not mistaken. so anyways, is 9:5 too high or is that gonna be ok, or should i go 9:1 or 8:8... im confused, and the guy at Arias pistons isnt helping... thanks
12-01-2004, 07:47 PM
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Re: (Bryson)
definately not too high! I'd take an extra full point of compression in trade for 5-7 extra psi anyday! I was at 9.8:1 in my built ls/vtec with turbo intentions. just ask tony the tiger....
if you are building a car that will see the street and somewhat every-other-daily driving. go with 9.5:1 or higher.
if you are building a car that will see the street and somewhat every-other-daily driving. go with 9.5:1 or higher.
12-01-2004, 07:53 PM
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Re: (RenoRacing)
im running 10.5:1 on my street car. Its a car i drive Daily and i take the the Drag strip once in a while but mostly its for the Road Tracks. Some friends and i rent out Talladega speed way to run on its road coruse.
12-01-2004, 07:58 PM
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Re: (Bryson)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bryson »</TD></TR><TR><TD CLASS="quote">NO, and I hate this rumor.
I really wish I was running 10:1 in my motor. Quicker spool, and more power from less boost. </TD></TR></TABLE>
NO, and I hate this rumor.
Take it from me. I went from 10.2:1 to 7.8:1 in my B16. Didn't notice ANY DIFFERENCE in how quickly the turbo spools. Sure, 7.8:1 may very well be overkill, but atleast if I ever want to I can mill the head down or run a thinner headgasket to boost the compression.
Take it from me, lower compression setups for street cars are more fun. I have a friend who built his B16 up at the same time I was, except he had his block sleeved and is running 10:1 compression. Guess who's disapointed with their setup? He is, because he can't run the boost I can on pump gas, and he's PO'ed that his turbo doesn't spool any quicker.
I really wish I had an extra 500 bucks and a weekend laying around. Get some 10:1 pistons in there, dyno it and datalog some pulls and show you that huge difference in compression.
I really wish I was running 10:1 in my motor. Quicker spool, and more power from less boost. </TD></TR></TABLE>
NO, and I hate this rumor.
Take it from me. I went from 10.2:1 to 7.8:1 in my B16. Didn't notice ANY DIFFERENCE in how quickly the turbo spools. Sure, 7.8:1 may very well be overkill, but atleast if I ever want to I can mill the head down or run a thinner headgasket to boost the compression.
Take it from me, lower compression setups for street cars are more fun. I have a friend who built his B16 up at the same time I was, except he had his block sleeved and is running 10:1 compression. Guess who's disapointed with their setup? He is, because he can't run the boost I can on pump gas, and he's PO'ed that his turbo doesn't spool any quicker.
I really wish I had an extra 500 bucks and a weekend laying around. Get some 10:1 pistons in there, dyno it and datalog some pulls and show you that huge difference in compression.
12-01-2004, 08:00 PM
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Re: 9:5:1 cr too high for turbo??? (pubestripe)
a b16 and a b17 are differdent in the intake and exhaust ports but they will both bolt up to a b16 block. As far as the compression ratio is concerned it depends soley on how much boost you intend to push. 9.5:1 should be ok as long as you don't intend to push 15 psi. how much boost do you want to push and people can tell you what compression ratio would be best.
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12-01-2004, 08:04 PM
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Re: (b16coupe)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b16coupe »</TD></TR><TR><TD CLASS="quote">
NO, and I hate this rumor.
Take it from me. I went from 10.2:1 to 7.8:1 in my B16. Didn't notice ANY DIFFERENCE in how quickly the turbo spools. Sure, 7.8:1 may very well be overkill, but atleast if I ever want to I can mill the head down or run a thinner headgasket to boost the compression.
Guess who's disapointed with their setup? He is, because he can't run the boost I can on pump gas, and he's PO'ed that his turbo doesn't spool any quicker.
</TD></TR></TABLE>
I'm not sure that I can take this for more than a grain of salt. 7.8:1??? where would you go about ordering these compression pistons? and 7.8:1 in a already torqueless(before boost) b16 would make for not too much or a low rpm daily driver.
you're correct. he cannot run the same boost you can on pump gas, but he doesn't need to. he can run 12psi compared to your 20psi and make the same power.
NO, and I hate this rumor.
Take it from me. I went from 10.2:1 to 7.8:1 in my B16. Didn't notice ANY DIFFERENCE in how quickly the turbo spools. Sure, 7.8:1 may very well be overkill, but atleast if I ever want to I can mill the head down or run a thinner headgasket to boost the compression.
Guess who's disapointed with their setup? He is, because he can't run the boost I can on pump gas, and he's PO'ed that his turbo doesn't spool any quicker.
</TD></TR></TABLE>
I'm not sure that I can take this for more than a grain of salt. 7.8:1??? where would you go about ordering these compression pistons? and 7.8:1 in a already torqueless(before boost) b16 would make for not too much or a low rpm daily driver.
you're correct. he cannot run the same boost you can on pump gas, but he doesn't need to. he can run 12psi compared to your 20psi and make the same power.
12-01-2004, 08:10 PM
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Re: (92SleepyHB)
^look at this guys(92sleepyHB signature and tell me that his compression isn't doing him right!?
here's one of the high vs. low debates.
https://honda-tech.com/zerothread?id=830284
here's one of the high vs. low debates.
https://honda-tech.com/zerothread?id=830284
12-01-2004, 08:11 PM
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Re: (92SleepyHB)
Since these are all about DOHCs, what about a D15 or D16, what would be a good compression for daily driver / occasional track, thanks in advanced, you guys rock 
12-01-2004, 08:16 PM
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Re: (RenoRacing)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RenoRacing »</TD></TR><TR><TD CLASS="quote">
I'm not sure that I can take this for more than a grain of salt. 7.8:1??? where would you go about ordering these compression pistons? and 7.8:1 in a already torqueless(before boost) b16 would make for not too much or a low rpm daily driver.
you're correct. he cannot run the same boost you can on pump gas, but he doesn't need to. he can run 12psi compared to your 20psi and make the same power.</TD></TR></TABLE>
7.8:1 is a set of off the shelf JE dished pistons for a GSR motor. 9:1 on a B16 is flat tops, so take a dished piston and slap it in a B16 and you get lower compression. It feels slightly more sluggish off boost (IE, it needs a pinch more throttle starting on a hill, that's about it) but it's not like i'm wallowing in pain and suffering because I can't make it through the intersection doing 25 because it has no power.
Only differences between our motors is I'm running Skunk2 Stage 1 cams, he's running CTR cams. Both have SC61's on inline pro mani's, eagle rods, JE pistons, stock B16 head with springs/retainers, victorX IM's, hondata. I'm running mine in an EF sedan, his is an EG hatch, we're pretty similar in weight. My car at 16 psi hangs with his car at 15 psi. If you seriously think 2.2 full points in compression is going to make the same difference as 8 pounds of boost, you need to give your head a shake.
FWIW I really don't know what the limits are on his motor with 10:1 compression. He might be able to run 19 pounds of boost on pump gas, he might not, although I doubt it. If somebody showed me some CONCRETE proof that I would have no problems making a reliable 400 WHP on 91 octane with a 10:1 B16, I probably wouldn't have run such low compression, but untill the day that my B16 cracks a sleeve and somebody shows me that proof, I'm going to keep driving my low comp setup.
I'm not sure that I can take this for more than a grain of salt. 7.8:1??? where would you go about ordering these compression pistons? and 7.8:1 in a already torqueless(before boost) b16 would make for not too much or a low rpm daily driver.
you're correct. he cannot run the same boost you can on pump gas, but he doesn't need to. he can run 12psi compared to your 20psi and make the same power.</TD></TR></TABLE>
7.8:1 is a set of off the shelf JE dished pistons for a GSR motor. 9:1 on a B16 is flat tops, so take a dished piston and slap it in a B16 and you get lower compression. It feels slightly more sluggish off boost (IE, it needs a pinch more throttle starting on a hill, that's about it) but it's not like i'm wallowing in pain and suffering because I can't make it through the intersection doing 25 because it has no power.
Only differences between our motors is I'm running Skunk2 Stage 1 cams, he's running CTR cams. Both have SC61's on inline pro mani's, eagle rods, JE pistons, stock B16 head with springs/retainers, victorX IM's, hondata. I'm running mine in an EF sedan, his is an EG hatch, we're pretty similar in weight. My car at 16 psi hangs with his car at 15 psi. If you seriously think 2.2 full points in compression is going to make the same difference as 8 pounds of boost, you need to give your head a shake.
FWIW I really don't know what the limits are on his motor with 10:1 compression. He might be able to run 19 pounds of boost on pump gas, he might not, although I doubt it. If somebody showed me some CONCRETE proof that I would have no problems making a reliable 400 WHP on 91 octane with a 10:1 B16, I probably wouldn't have run such low compression, but untill the day that my B16 cracks a sleeve and somebody shows me that proof, I'm going to keep driving my low comp setup.
12-01-2004, 08:50 PM
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Re: (b16coupe)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b16coupe »</TD></TR><TR><TD CLASS="quote">
NO, and I hate this rumor.
Take it from me. I went from 10.2:1 to 7.8:1 in my B16. Didn't notice ANY DIFFERENCE in how quickly the turbo spools. Sure, 7.8:1 may very well be overkill, but atleast if I ever want to I can mill the head down or run a thinner headgasket to boost the compression.
Take it from me, lower compression setups for street cars are more fun. I have a friend who built his B16 up at the same time I was, except he had his block sleeved and is running 10:1 compression. Guess who's disapointed with their setup? He is, because he can't run the boost I can on pump gas, and he's PO'ed that his turbo doesn't spool any quicker.
I really wish I had an extra 500 bucks and a weekend laying around. Get some 10:1 pistons in there, dyno it and datalog some pulls and show you that huge difference in compression.</TD></TR></TABLE>
Its all about timing my freind...
A 10:1 motor can make just as much as that 7.8:1 motor with less timing on the same fuel.
However, off boost those two motors would seem worlds apart. The 10:1 motor would be much more responsive, while the 7.8 would be laggy.
NO, and I hate this rumor.
Take it from me. I went from 10.2:1 to 7.8:1 in my B16. Didn't notice ANY DIFFERENCE in how quickly the turbo spools. Sure, 7.8:1 may very well be overkill, but atleast if I ever want to I can mill the head down or run a thinner headgasket to boost the compression.
Take it from me, lower compression setups for street cars are more fun. I have a friend who built his B16 up at the same time I was, except he had his block sleeved and is running 10:1 compression. Guess who's disapointed with their setup? He is, because he can't run the boost I can on pump gas, and he's PO'ed that his turbo doesn't spool any quicker.
I really wish I had an extra 500 bucks and a weekend laying around. Get some 10:1 pistons in there, dyno it and datalog some pulls and show you that huge difference in compression.</TD></TR></TABLE>
Its all about timing my freind...
A 10:1 motor can make just as much as that 7.8:1 motor with less timing on the same fuel.
However, off boost those two motors would seem worlds apart. The 10:1 motor would be much more responsive, while the 7.8 would be laggy.
12-01-2004, 11:42 PM
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Re: (Bryson)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bryson »</TD></TR><TR><TD CLASS="quote">NO, and I hate this rumor.
I really wish I was running 10:1 in my motor. Quicker spool, and more power from less boost. </TD></TR></TABLE>
I wish I could have done the same too. I thought the average 9:1 was the answer, then i thought no 9:5:1 would be good, but on a street car..... the higher the better imo. All that matters is the tune. Tuning is the key to building a successful reliable street car. FOR SURE.
I really wish I was running 10:1 in my motor. Quicker spool, and more power from less boost. </TD></TR></TABLE>
I wish I could have done the same too. I thought the average 9:1 was the answer, then i thought no 9:5:1 would be good, but on a street car..... the higher the better imo. All that matters is the tune. Tuning is the key to building a successful reliable street car. FOR SURE.
12-02-2004, 02:02 AM
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Re: (jDMJeRk)
All replies have valid points, but why go turbo if u dont plan on using it to its full potential (high boost). If u plan on running high boost atleast some time or another street or track ur gonna need the right setup. 10:1 compression...i smell detonation maybe thats just me by high boost i mean 22 and up pounds.
12-02-2004, 04:36 AM
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Re: (eL`mIEkLo)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eL`mIEkLo »</TD></TR><TR><TD CLASS="quote">All replies have valid points, but why go turbo if u dont plan on using it to its full potential (high boost). If u plan on running high boost atleast some time or another street or track ur gonna need the right setup. 10:1 compression...i smell detonation maybe thats just me by high boost i mean 22 and up pounds.</TD></TR></TABLE>
Not all turbos are Full potential High boost. Your looking for a turbo that will match your motor and what your using it for. Honestly i think the turbo i have is really overkill for my setup but i'll found out when its running.
Not all turbos are Full potential High boost. Your looking for a turbo that will match your motor and what your using it for. Honestly i think the turbo i have is really overkill for my setup but i'll found out when its running.
12-02-2004, 05:11 AM
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Re: (pubestripe)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by pubestripe »</TD></TR><TR><TD CLASS="quote">i plan on going 20 psi... i want big numbers for the track...</TD></TR></TABLE>
I hope you don't mean Rock Falls...that track sucks. see sig.
I hope you don't mean Rock Falls...that track sucks. see sig.
12-02-2004, 07:41 AM
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i hated running low compression in my old car. it made good numbers but was a dog until the turbo spooled up. i am running 10.28:1 now (isnt done yet but i cant wait to drive it) link below sfwd hatch
12-02-2004, 08:35 AM
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Re: (Bryson)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bryson »</TD></TR><TR><TD CLASS="quote">
A 10:1 motor can make just as much as that 7.8:1 motor with less timing on the same fuel.
</TD></TR></TABLE>
Why didn't Jeff Evans feel "safe" taking my motor to 300whp on pump gas? Because I have 11.0:1 compression ratio.
I was pissed I didn't go with a thicker headgasket. . .
A 10:1 motor can make just as much as that 7.8:1 motor with less timing on the same fuel.
</TD></TR></TABLE>
Why didn't Jeff Evans feel "safe" taking my motor to 300whp on pump gas? Because I have 11.0:1 compression ratio.
I was pissed I didn't go with a thicker headgasket. . .
12-02-2004, 08:43 AM
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Re: (m R g S r)
I believe he would have pushed it higher but I'm sure he wanted to be safe. Higher compression is great but very small room for error, even the best of the best can make a small mistake. Better safe than sorry is why I would think he didn't want to go much higher. I run 10.5.1 everyday and love it.
12-02-2004, 08:52 AM
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Re: (m R g S r)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by m R g S r »</TD></TR><TR><TD CLASS="quote">
Why didn't Jeff Evans feel "safe" taking my motor to 300whp on pump gas? Because I have 11.0:1 compression ratio.
I was pissed I didn't go with a thicker headgasket. . . </TD></TR></TABLE>
There's a big difference between 11:1 and 10:1 on a turbo car.
Why didn't Jeff Evans feel "safe" taking my motor to 300whp on pump gas? Because I have 11.0:1 compression ratio.
I was pissed I didn't go with a thicker headgasket. . . </TD></TR></TABLE>
There's a big difference between 11:1 and 10:1 on a turbo car.
12-02-2004, 08:57 AM
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Re: (b16coupe)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b16coupe »</TD></TR><TR><TD CLASS="quote">
If somebody showed me some CONCRETE proof that I would have no problems making a reliable 400 WHP on 91 octane with a 10:1 B16, I probably wouldn't have run such low compression, but untill the day that my B16 cracks a sleeve and somebody shows me that proof, I'm going to keep driving my low comp setup.</TD></TR></TABLE>
Hybrid901 made 620whp on 10:1 with C16 and 414whp with pump gas. Read through the thread he mentions later in the post the pump gas results.
https://honda-tech.com/zerothread?id=834580.
There's your CONCRETE proof.
If somebody showed me some CONCRETE proof that I would have no problems making a reliable 400 WHP on 91 octane with a 10:1 B16, I probably wouldn't have run such low compression, but untill the day that my B16 cracks a sleeve and somebody shows me that proof, I'm going to keep driving my low comp setup.</TD></TR></TABLE>
Hybrid901 made 620whp on 10:1 with C16 and 414whp with pump gas. Read through the thread he mentions later in the post the pump gas results.
https://honda-tech.com/zerothread?id=834580.
There's your CONCRETE proof.
