internal engine upgrades for turbo

ASSISTANCE Forced Induction
1

as soon as winter comes around im going to start taking out my b18a and rebuild it for a turbo setup for next year. ive been looking at a couple turbo set ups for b18a’s but most people seem to keep stock internals and what not. im going to be rebuilding the engine from the ground up (rings, bearings, seals, gaskets, etc.) all the setups ive been looking at are pushing more or less 300 hp on stock engines not even rebuilt.

my question is if my goal is 300whp, what internally would i need to upgrade for this to be a reliable non ghetto turbo build. im full aware of rod and head bolts. with all the internally stock setups ive seen do i really need forged pistons and rods for 300hp?? and then the head work? cams, valves, springs, retainers??whats recommended for my 300whp goal?

the way i see it is if theres many people running fully stock non rebuilt b18a/b’s on boost and they’re holding up, then a fully rebuilt one shouldn’t be a problem?

2

you’ve got the right idea. from a former turbo lover (i’m an N/A guy now) LS motors can handle boost really well (so can any honda motor, honestly) its just all in the tune. the main factor involved is always going to be money. if you have the money to do everything right, then you will be fine. now keep in mind that its more than just the build, you could “bulletproof” the whole motor/turbo setup, but without a good tune, you’ll have nasty detonation that’ll really rain on your parade.

using reputable aftermarket parts for your build is only going to help (when installed properly) if you have the money for them, forged rods and pistons will be able to handle a little more abuse than stock units. though the stock rods and pistons really aren’t that bad at all, which is why you see so many internally stock LS turbo’s out there making good power. the key, is the tune.

you pretty much have the right idea, as long as everything is done right, you won’t have any problems with your build. and if the tune is done right, it should be just as reliable, and last just as long as a stock LS without a turbo. you’re fuel economy won’t be as good, depending on how your car is tuned, but for the most part, unless you are getting rid of A/C and power steering, that’ll probably be your only sacrifice.

cams will help make power, obviously. crower’s 403-T’s are great turbo specific cams for LS motors. a little headwork will help, but isn’t terribly necessary. a mild port and polish will help the flow, but won’t make gobs of power. replacing the valves with stainless steel would be beneficial, as well as a 3 (or 5) angle valve job will help with flow. but again, its not necessary and you wont be hurting anything if you dont do it. dual valve springs are pretty much a necessity with the 403’s, i believe (but dont quote me on that one) but again, it couldn’t hurt. a little piece of mind is better than a big pile of shit in the end.

make sure to have the cylinders honed as well. boring wont be necessary as long as the cylinders aren’t scarred in anyway. just a good hone, without taking off any meat (so to speak) to clean/smooth out the walls for a good seal for the rings. having the crank balanced, cleaned etc will help take stress off of the rotating mass (the enemy of the internal combustion engine) essentially, like you stated, a full engine restoration with quality aftermarket parts for reinforcement is all you need for the ENGINE. the real money will be spent on the tune, the proper AF ratio is critical on a turbocharged engine, whether it came from the factory that way or not.

good luck, bro and keep us posted.

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haha well being a mechanic i do a lot of the stuff myself. besides machining work. buy honing the cylinder walls and stuff is no problem. i forgot to mention that i took out my p/s and a/c a while ago so my engine bay is bare and begging for a nice turbo to take up the space. im more of a n/a guy but looking at turbo set ups lately have really lead me to wanting to build one at least once in my life. sorta the opposite of you haha. also my friends sr20det swapped 240 isnt helping me. hearing that turbo spool and the bov.

my engine is in really good condition and still has very good compression for 276 000km on it. i think for bottom end work ill just shotpeen the rods with arp rod bolts and that should be fine you think??always for 300hp.

4

yeah, imcnblu pretty much said it best lol. you guys both have the right ideas. Stock cams also work quite well. Im building a GSR within the next couple months, so i have an idea of what you’re gonna go through. But im gonna possibly upgrade a lil bit more than you will.

My original goal was 300whp as well, but imma shoot for around 325whp and the main reason i would upgrade as much as possible is just in case you wanna amp up the boost a lil bit. I was afraid that i would get boost hungry and want a little more power later on, or if a srt-4 wanted a little taste. Thats just my suggestion tho. But good luck with the build

5

the ls is a good motor to boost. shotpeen the rods won’t do much at all. arp rod bolts are a good idea. but why not just spend a couple hundered on some nice eagle h beam rods? most ask 300 max for the rods and arp rod bolts together. 300hp is a lot to ask out of the ls without doing anything to it. don’t rev past stock rev limit (not like it makes any power past 5800rpm anyways). stock valve train float FTL! the rods like to peek through the block every now and then when u over rev. a stock ls head is gonna kill ur hp numbers. u’ll have a hard time making 300whp without some serious psi to pick up the slack. but then with high boost u’ll see where stock pistons fail. ringlands will go first, then they start to melt. i’ve seen around 280whp max on a stock ls with a nice turbo setup. i hope i’ve convinced u to build it.

it may not sound like it but i’m actually building myself a nice little ls-t myself

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well thats why im asking. if i have to build it then i will i dont really mind. i want a good reliable turbo set up. i was just saying that ive seen setups on stock internals and they seemed to be putting out the same power im looking for.

its just that im more familiar with n/a setups. my original plan was to build a fully built ls/vtec. full port and polish, high compression, not one thing left stock. but recently ive decided i wanted to build a turbo set up but im not very familiar with the turbo world. all advice is greatly appreciated.

whats a good size turbo for 300whp with not to much lag?

7

http://www.honda-tech.com/zerothread?id=1323059

i would read that thread. awesome info.

i’ll be running an sc61 .63 a/r hot side and .70 a/r compressor. thats gonna be to big for what u need it for. i believe most like to run the 57 or 60 trim with either a .48a/r or .63a/r. the .63 a/r will ofcourse be harder to spool and rated for more hp. it’s better to figure out what ur engine internals will be for both the head and block and pick a turbo that best suits what u need it to do. some people pick the turbo and build the engine for the turbo. it’s up to you and your hp goals. good luck!

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you have alot of great advise here. as a owner of a LS-T, on my 3rd engine, have found out the hard way to spend the money to build it right the first time. every part counts.

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awesome link BBP-GS DA. going through all the set ups and seeing the numbers they’re putting down is really helping me out.

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how much whp would i be able to get with a garrett t3, .48 turbine, .42 compressor??looks like a nice little fast spooling turbo to me.

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depends on how many lbs of boost you can get out of it. that is a small to medium sized turbo, good for daily use. if memory serves me correctly, thats AROUND the same size as a stock DSM turbo. i think the DSM turbo’s are a little smaller. i’m not 100% on it, i’m a little slackin on my turbo size knowledge these days. i’m an NA guy now.

anywho, i’d say the most power you are going to get out of it (depending on engine internals/headwork) and how good your shop can tune it, you’d get about 260-275whp AT MOST. but yeah, it should spool pretty quick. with an LS motor (with a “redline” at 6800 or 6500 if you’re obd0) you will probably get maximum boost at around 3500rpms or so.

this is a VERY ROUGH estimate, could be sooner. again, i’m a little “lagging” (terrible pun) with my forced induction knowledge since i’ve been into all motor cars.

12

sounds exactly what im looking for. i brought my goal down a little since its my first turbo setup. im looking at making 250whp on stock engine fully rebuilt. from all the setups ive seen, the b18a should handle this very well. but recently ive figured out a way to save cash on my teg build. so who knows, maybe ill build the engine a bit.

im more of a NA guy as well. but a turbo teg seems so fun. if i ever build a NA build, its for sure in a CRX. those things are just so light.

however i might be buying another teg. since its a mint chassis/body (and here in quebec, canada, that doesnt really exist) and my current teg needs a bit of work. it comes with a b16. so if that goes through then i might just cancel my turbo plans and fully build the b16. or hell, i can turbo the b16 haha, but i dont think id turbo a vtec engine. got to stay true to NA honda.

13

i had one on a D16Z6 i had boosted and wanted to kill myself, it spooled fast, but had no top end power and was out of breath by 4500

i liked the 60/63 i had on it before, was spooled by 3700, had nice top end power, and didnt run out of breath

and thats on a 1.6L single cam. i’d hate to imagine that little turbo on an LS

if you want some good turbo info check out homemadeturbo.com

read around and most anything you have a question for has already been posted and discussed to death

14

thanks a lot for the link. ive been checking out that site a bit. picked up a mint 91 RS today. gonna have to convert it to obd1.

15

if u wanted to u could put forged rods on stock ls rods.my buddies b16 is running stock rods and je pistons 15psi all day every day.jus tune it.i suggest that to anyone under boost tune it.if u have been threw as many motors as i have ull learn to tune everything.its worth it belive me.

16

why buy forged pistons and not upgrade the rods while your there, its just a couple hun extra and its apart anyway

my advice, if your gonna build it, build it right, otherwise dont even bother takeing it apart

my last build was 4K in parts alone, because i didnt want to cut any corners (and i have semi expensive tastes)

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[QUOTE=Anubis_4_99;1722564]why buy forged pistons and not upgrade the rods while your there, its just a couple hun extra and its apart anyway

my advice, if your gonna build it, build it right, otherwise dont even bother takeing it apart

my last build was 4K in parts alone, because i didnt want to cut any corners (and i have semi expensive tastes)[/QUOTE]

not everyone has deep pockets. i agree do it all.but if u cant afford it pistons can suit u just fine

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i dont have deep pockets either, but it was apart so i decided to do it all instead of haveing to pull it apart again

you can get eagle H beam rods for 300 shipped brand new

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and those H beam rods will hold up just fine on a moderately boosted setup. replace the bearings etc. and you’ll be in business for some SERIOUS boost.