89 prelude si JDM b20a swap questions.
03-21-2016, 06:36 PM
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89 prelude si JDM b20a swap questions.
So I swapped a jdm b20a into my 89 prelude. What's a good build I can do to this car I am thinking boost! I am use to a dsm at 300hp and so what's the best build I can do. I have a pr4 scocketed I can get a b20a base map thrown on correct? I have a tunner out here that does obd-0.
03-21-2016, 07:08 PM
#2
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Re: 89 prelude si JDM b20a swap questions.
boomslang.us for a conversion harness. 3g preludes are not like other obd0 honda harnesses, they have a specific conversion harness.
and yeah, boost is your best bet. depending what you do for a setup, I can probably make you a pretty accurate basemap. I've been tuning 3g's for about a decade now
and yeah, boost is your best bet. depending what you do for a setup, I can probably make you a pretty accurate basemap. I've been tuning 3g's for about a decade now
03-22-2016, 07:41 AM
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Re: 89 prelude si JDM b20a swap questions.
Some questions...
How much can b20a handle stock around 120k. Did compression test all good.
What upgrades should be done?
Thanks
How much can b20a handle stock around 120k. Did compression test all good.
What upgrades should be done?
Thanks
03-22-2016, 09:32 AM
#4
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Re: 89 prelude si JDM b20a swap questions.
bone stock should be good to around 200.
weakest link is the rods. a common swap is oem h23 rods, they're identical dimensions, still have the oiling holes, but are noticeably thicker. I run oem h23 rods in my car, 300+ tq and hp currently.
replace the rod and main bearings before boosting, even if you dont swap the rods. our motors are known for spitting rods out the block due to rod bearing failure.
second weakest link is pistons, which break ringlands like clockwork around 230tq-250tq, depending on how conservative the tune is. so anything over 230tq I would recommend forged pistons.
valve springs are a good idea too. currently the only aftermarket valve springs for us are actually Supertech springs for the H22. oddly enough, they're the only h22 springs that fit our motors properly. But they're super stiff, so use ONLY the inners OR outers from supertech, and the stock springs for the opposite. IE: I have supertech inner springs and stock outer springs. but you can go either way. using supertech inner and outer is too stiff and you risk shattering the cam caps.
and depending how far you go with power, there's also cometic headgaskets and ARP head and main studs, and several options for aftermarket cams
weakest link is the rods. a common swap is oem h23 rods, they're identical dimensions, still have the oiling holes, but are noticeably thicker. I run oem h23 rods in my car, 300+ tq and hp currently.
replace the rod and main bearings before boosting, even if you dont swap the rods. our motors are known for spitting rods out the block due to rod bearing failure.
second weakest link is pistons, which break ringlands like clockwork around 230tq-250tq, depending on how conservative the tune is. so anything over 230tq I would recommend forged pistons.
valve springs are a good idea too. currently the only aftermarket valve springs for us are actually Supertech springs for the H22. oddly enough, they're the only h22 springs that fit our motors properly. But they're super stiff, so use ONLY the inners OR outers from supertech, and the stock springs for the opposite. IE: I have supertech inner springs and stock outer springs. but you can go either way. using supertech inner and outer is too stiff and you risk shattering the cam caps.
and depending how far you go with power, there's also cometic headgaskets and ARP head and main studs, and several options for aftermarket cams
03-23-2016, 07:40 PM
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Re: 89 prelude si JDM b20a swap questions.
What's the best compression ratio for boost when I go forged pistons. Sleeve block or block guard? I am looking to achieve a lot of power. What's a good turbo? Injectors? Fuel pump? My buddy's saying pull my walbro 255 from my crx and buy some 1000cc injectors? As for cams to what's a good set he says Brian crower isn't good.
03-24-2016, 04:43 AM
#6
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Re: 89 prelude si JDM b20a swap questions.
it's a closed deck block, so you can't use a block guard. closed deck is stronger than a block guard anyway.
best compression ratio will depend on what fuel you plan to use. if you want it for 91 pump gas, 9.5:1 will be best, for 93 pump gas 9.5:1-10.0: would be best. for e85 10.0:1 would be best.
there is nothing off the shelf at those ratios though, so you'd either need custom, or to atler hg thickness and shave the head specific amounts to achieve the ratio you want. for example, I currently run 8.5:1 pistons, but my actual compression ratio is 9.7:1 due to hg and head mods.
no point in sleeving unless you want to run higher than 400tq.
fuel pump, walbro 255HP. the HP version is the important part, it is NOT the same as the standard 255lph pump. it actually bothers me that so many people use the 255lph in their boost builds instead of the HP version. HP = high pressure.
Cams, a few companies have a turbo grind. or you can just get any stage 1 cam will be great, just get some gears to dial out the overlap a bit.
and crower cams are actually quite good for our motor. Crower and Web camshafts are the two companies I typically recommend for the 3gp.
for the rest, that all depends on what you want for power, how fast you want it to spool, where you want the powerband to be focused, and much more.
best compression ratio will depend on what fuel you plan to use. if you want it for 91 pump gas, 9.5:1 will be best, for 93 pump gas 9.5:1-10.0: would be best. for e85 10.0:1 would be best.
there is nothing off the shelf at those ratios though, so you'd either need custom, or to atler hg thickness and shave the head specific amounts to achieve the ratio you want. for example, I currently run 8.5:1 pistons, but my actual compression ratio is 9.7:1 due to hg and head mods.
no point in sleeving unless you want to run higher than 400tq.
fuel pump, walbro 255HP. the HP version is the important part, it is NOT the same as the standard 255lph pump. it actually bothers me that so many people use the 255lph in their boost builds instead of the HP version. HP = high pressure.
Cams, a few companies have a turbo grind. or you can just get any stage 1 cam will be great, just get some gears to dial out the overlap a bit.
and crower cams are actually quite good for our motor. Crower and Web camshafts are the two companies I typically recommend for the 3gp.
for the rest, that all depends on what you want for power, how fast you want it to spool, where you want the powerband to be focused, and much more.
03-24-2016, 04:49 AM
#7
Honda-Tech Member
Re: 89 prelude si JDM b20a swap questions.
for reference for your buddy, here are some charts I put together a while back after measuring the cams in an actual motor. I don't remember which grind the Crowers were though.
<a href="http://s62.photobucket.com/user/crluver123/media/crowerexhaustcomparison.jpg.html" target="_blank"><img src="http://i62.photobucket.com/albums/h101/crluver123/crowerexhaustcomparison.jpg" border="0" alt=" photo crowerexhaustcomparison.jpg"/></a>
<a href="http://s62.photobucket.com/user/crluver123/media/crowerregrind-5intakecomparison.jpg.html" target="_blank"><img src="http://i62.photobucket.com/albums/h101/crluver123/crowerregrind-5intakecomparison.jpg" border="0" alt=" photo crowerregrind-5intakecomparison.jpg"/></a>
<a href="http://s62.photobucket.com/user/crluver123/media/crowerexhaustcomparison.jpg.html" target="_blank"><img src="http://i62.photobucket.com/albums/h101/crluver123/crowerexhaustcomparison.jpg" border="0" alt=" photo crowerexhaustcomparison.jpg"/></a>
<a href="http://s62.photobucket.com/user/crluver123/media/crowerregrind-5intakecomparison.jpg.html" target="_blank"><img src="http://i62.photobucket.com/albums/h101/crluver123/crowerregrind-5intakecomparison.jpg" border="0" alt=" photo crowerregrind-5intakecomparison.jpg"/></a>
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