So, I'm building my LS from the block up, my Goal is to have 400-450hp.
I plan on having the build tuned for 15+ psi initially and it will be tuned on Hondata s100.

What I'm doing:
81mm bore Wiseco Pistons @ 8.5:1 w/ eagle H rods.
Brian Crower Stage 2 Turbo cams w/ BC Valvesprings and Titanium Retainers
Brian Crower SS valves
Supra 440cc injectors (for the moment)
a GTX3071R w/ FMIC hard pipping.

there are more mods that I'm adding but I'm just highlighting the majors. I've been hearing that I don't necessarily need the whole Valvetrain upgrades since LS' rev relatively high around 7-8grand. Figured I would pop on here and see what the more experienced members of honda tech have to say?

 

those injectors will only get you to 300 ish whp. and you'll have an easier time hitting your goals with a stock b16 head over a built ls head. ls heads flow pretty shitty and port work is expensive. have you talked to your tuner about useing the hondata s100. if you wanna stick with hondata id go s300. Also no reason to go 8.5:1 for your cr. as long as you have a good tuner you'll be much better off with at least a 9.6:1 CR. Have you talked to a tuner at all about your goals and setup. That will prolly be your best source of advice for your build.

Also check out the LS-T thread on here. lots of good advice and setups with dyno numbers. you just have to look thru a few pages.

 

go bigger on your injectors and higher on your Cr

 

About the injectors I'll be getting some 1000cc's from RSP just need some bigger injectors for now since I've got none for the engine yet, buddy of mine had a couple junked supras sitting around and he handed me some 440's, But I've also got a friend who will port/polish my head only for $100, plus I'm not a fan of hybrid builds. Haven't talked to my tuner yet, But I've got a group of friends and we all build cars, I'm just one of the younger ones they've been passing advice to so I've got a general idea. If anything I'd just keep the stock CR at 9.2 maybe raise it with a thinner gasket. Since I'm buying the whole turbo/fmic/hondata off a buddy I think the s100 should do fine since it was already on a bone stock LS with just a garret super 60 series on 7 psi that put 193 and ran mid 13's. I was told only difference from s100-300 is options but the tuning doesn't really change, you can just datalog and such.

 

I would bump your CR up to at least 9.5:1 otherwise your spool up will suffer.

I wouldn't let your buddy PnP your head unless he's been doing it for years and has proven results, just leave it stock. The real gains on an LS head are seen from valve jobs.

Don't even try to rev your LS to 8k stock, you'll end up needing to buy a whole new head. Just upgrade the valvetrain if you want, get a valve job and rev it to 7500.

 

True, 9.5 would help my low end while not in boost and would help spool faster.

And on my Buddy PnP'ing my head he's pretty experienced owns 3 supra's with 7m's and a 2jz all putting 500+ rwhp. lol


So far I'm leaning towards buying the whole valvetrain assembly.. just seems more-so common logic while trying to put out impressive numbers.

 

So your buddy has all kinds of experience in porting Honda heads? I'm telling you Porting and polishing is an art, its not just making holes bigger. Did he port all those heads on his cars? Just because they make 500+ whp doesnt mean crap, maybe he did a horrible PnP on them and they would all be making 600+ with a proper PnP.

I'm not trying to knock your buddy, I'm just saying PnP is something you learn from experience and not just from doing a few heads. Besides the B-series heads already flow pretty well. If you want head work take it and get a valve job. A bad PnP from an inexperienced person can ruin a head. The only real way to tell if he is skilled is by getting the heads flowtested.

 

he can stick with the stock ls head with valvetrain upgrades and cams and hit his goal no problem. You dont need a vtec head to do it, just takes more boost is all. As for RPM the heads dont like alot of rpm, be sure to run a obd1/2 vtec oil pump or obd2 ls oil pump to help with rocker wear. Dont port the head, it really isnt nessesary for the power level and if you dont know honda heads you can do more damage then good.

Def bump the compression ratio up to 9.5 range. 8.5 really isnt nessesary and you wil benefit from the higher comp. If your trying to obtain this power level on pump gas speak to a turbo professional on here about sizing because its going to take a decent amount of boost and you dont want detonation. If race gas is being used for your goals then the turbo you selected i think will be fine, for pump gas im unsure and dont want to stear you in wrong direction

 

Car's going to be run on e85.

And @ Ryan, he's done his own work to all of his cars. the 2jz is projected at 600hp+ hasn't been dropped into a car yet. Trust me I wouldn't take my head to my buddy if he wasn't experienced, I'm no idiot lol.

So stock ls head w/ the valvetrain I mentioned should be sufficient enough then? If so that's great. Definitely wasn't going to do any LS/Vtec conversion lol.

 

yes stock ported p75 head is fine. if its a pr4 head junk it and find a p75 head there dirt cheap, upgrade the springs and retainers and cams and your good to go. i wouldnt bother with valves

 

well said. you might also want to consider an aftermarket intake manifold to help in conjunction with the cams to carry the torque higher in the rpm range. this seems to be an issue with ls motors. i know i had issues with it dropping like a rock after 5500 rpms or so

 

yeah torque doesnt carry great with ls motors basically cause of one cam lobe you end up sacraficing on or the other. with turbo cams it should carry higher instead of nose diving so quickly like stock cams

 

Thanks for all the advice so far, and yeah I planned on either a skunk2 IM or getting a GS-R or ITR mani.. wasn't sure yet lol