I'm not asking about using a vtec head with the vtec system and leave it on the primary lobes. I'm wanting to run a set of killers, because for a dedicated race motor, that may cruise town once a month, it seems to make sense. It's easier to tune, and prevents fluctuations in oil pressure. I'd rather have that 12-15psi supplying the turbo personally. I realize i will lose bottom end power, but how often is your race motor gonna turn under 6k anyway?

 

It will cost about triple what a good aftermarket cam and valve train would be. No need to run vtec-killer cams. Even if you want a dedicated race car/ weekend warrior the vtec cam profiles are plenty big for some serious power. I've made 400 whp on a Mustang Dyno using stock gsr cams on a 10.0:1 Ls-vtec on e85 @ 18 psi. Made the same amount of power @ 10 psi using Blox B's on the same set-up

 

This

 

Again, I just don't know else to explain it. You are completely headed in the wrong directions for all the wrong reasons. VTEC elimination cams should be saved for N/A builds. You will lose more than you think down low which could hurt a few things - especially street driving. If you are set on the "VTEC Killer" cams, you need to bump that compression way up to 12:1+ to utilize them. You are just over complicating everything when for your moderate goals - it has been tried and proven time and time again. There are many different builds that what will get you there - pick one. 500+whp builds are common place these days.

That "extra oil pressure" comment just shows how much you don't know about turbos or Honda engines. Show me your typical V8 that can push 100+ psi oil pressure with just 10w30. It isn't going to happen. The CHRA of the turbo only should see a set range of oil pressure. Depending on what turbo you have the pressure requirement will vary - this is the whole point of resteictors/restrictions that are built in. Again, over thinking the basics to the extreme. You need to better educate yourself.

If you want to keep listening to guys that build 4 second 1/8th mile cars instead of 4 second 1/4 mile cars - be my guest. You need to get out of the domestic mode of thinking.

 

^^OP: Pay attention to this

Hundreds of people have built setups exactly like what you're explaining...

KISS: Keep It Simple, Stupid

 

Seriously though, spend the money putting a sleeved block together with decent compression. Good turbo, solid setup, good tune -> go beat the **** out of it.

This isn't difficult, stop making it that way.

 

Well, I've got the plan for the bottom end, i guess I'll do more research into the top end. I'm still not really sold on the ls/vtec, mostly due to cost. I know for a fact i can go pick up 2-3 refurbished Ls heads for the price of 1 gsr. I have all the time in the world to do the pretty work myself, i just can't do the valve work. I think i may try porting out the ls first, then go lsv if i feel like its falling way short.

 

An LS head can work just fine, but even a ported LS head with cams is barely a match for a VTEC head. Further, the LS head isn't going to like the revs as much as a VTEC head would...

 

This. The VTEC is going to have more potential than the LS head. It was designed that way. The VTEC head is going to have better head flow and that's going to be really important at that high of horsepower, especially with a turbo. Not saying you can't do it, I just don't feel like it would be worth it. If you're trying to build a dedicated racecar, why not spend the extra to get what you want?

 

Are you capable of bench flowing the head to make sure you port each runner equally to prevent one cylinder from getting more air than the other and potentially causing a lean condition in one or more cylinders? You can find a complete gsr head $300-400. How is it you think you will save money running a ls head? I will be leaving my gsr head stock other than port matching and sleeving my gsr block with forged internals for a goal in the low 500 range. You don't have to do a thing to a vtec head until you get over the 500 range. And trust me I have figured every possible way to save money where I can since I am married putting my wife through nursing school with a child on one income.


As far as compression 10:1 would be the lowest I would go. I am planing to go at least 10.5:1 possibly 11:1. 8.5:1 would have no power once your out of boost. It would be a turd on wheels!

 

I'm not far out of that same situation. My wife just isn't in nursing school.

My thought in keeping the ls head and porting it was that I've already got the ls head, and for 30 bucks in scrolls,i can experiment with the port shape/characteristics to see how far i can take an ls head. I do have access to a flow bench, so that isn't a huge problem. And i may get into it and decide I'd rather just do an lsv, idk.

As far as the vtec head goes,i realize that killers are geared for high rpm, but I'm not sue how that makes them unstreetable. I realize it's a domestic, and maybe there is the difference, but a friend of ours has a 900 HP blown s10, and it sees the streets for the occasional car show, Sunday cruise. It's on a 4k stall, maybe more, but it's drivable. I've never had personal experience with killers, but i don't see how more lift/duration could hurt?

 

They're going to hurt because under ~5000rpm, the engine's needs are vastly different than when it is in boost and at higher RPM. The VTEC killer cams are only in VTEC (on the large lobe) meaning that in lower rpm, even though you've opened up a larger port for air to pass through, you will also have less air velocity moving through the head...its the Bernoulli principle. Anyway, at lower rpm this is going to bog out and feel like **** when its out of boost.

This is the same rationale behind GSR intake manifolds having ITBs...if you open all the channels in the IM prematurely, you increase the potential flow of air but decrease the speed at which it is entering the IM/head, and will lose torque and response as a result

 

Ok, that makes a bit of sense. I really kinda feel like an idiot because i overlook basic principals like that.

One last question.when selecting a vtec cam, do i just assume they retain the stock main lobe, and all changes are made to the vtec lobe, or do they alter both? Because the card i got with my bisi cam only listed one set of specs.

 

That, I do not know. I would imagine it depends on the cam. You can find cam spec sheets for OEM cams and compare them to aftermarket ones, if you care to do the leg work.

 

V8 knowledge really doesn't translate to the Honda world, some does, most don't. Consider this, if a stock 350 small block had the head flow of a stock b16 VTEC head it would make over 500whp from the factory

Pick a damn option and stick with it, rod ratio is pointless, a Honda motor will rev close to the moon regardless . Longer stroke = more torque, that's just common sense.

Stock cranks have been taken over 1000whp without issue, some cars are making close to 1300whp with a stock crank and oil pump..

And psi is irrelevant to power level, pick a turbo first then run whatever boost it takes to make the power you want, that's how it works

And with today's fuels and tuning solutions you can run 10:1 and still make close to 500whp on pump gas. And higher compression means more efficiency and better off boost performance, and will have little to no effect on spool times.

Stop talking to v8 people (even though I do v8s too, mostly ls7s) and get with the times. Most v8 guys are still trying to figure out the wheel, an overhead can system baffles almost 90% of these people lol

 

Your in this thread a little late for all that. And I'm going to say that building a 2500 hp 5xxci is not going to be that distant from the same basic principals for a 4 cyl. I realize not everything applies, but basics are basics. How do you think the original import racers figured out what to do? They applied v8 ideas and tech. They kept what worked, tried other things when something didn't.

I'll admit,i don't have a ton of Honda knowledge.I've been mostly into minis my whole life. I've daily drove a very mildly built z6, and want to learn more and build a track car. I'm kinda working with the resources I've got.I'm sorry if that upsets you.

And in respect to comparing the specs, i chant find but one set of specs for aftermarket cams, i would assume then to be for the vtec lobe. But i will look more into it whenever I'm not on my phone.

 

It depends on what you are looking at. The lower "staged" cams typically have closer to stock specs on primaries and more on the VTEC side. As you go up in the selection you will have increases in both primary and secondary lobes. As far as what is increased and by how much (lift or duration) will obviously rely on the design of the cam. The specs for most cams are out there, I assure you... you jist need to look harder. Also, yes, most of the specifications are for VTEC lobes.

 

10-4. Thanks to everyone for all the help

 

Well, do some research (on your own, no v8 guys lol) and then come ask questikns

And I knew high horsepower v8 builds take a lot of work and attention to detail, it's the same way with us Honda guys, or anyone that builds motors.

And here are two charts for compression ratio vs efficiency in 4 stroke gas engines



You can see here with a compression ratio in the 8.5:1 area you're only 51-52% efficient out of boost, that's horrible, that car will be sluggish and suck to drive unless you get into positive pressure all the time, not to mention a motor with compression in the 8s will have **** for fuel mileage, both in and out of boost

You referenced the vitara setup d series people use, with stock length rods that puts compression around 7.5:1 or lower depending on certain variables and anyone who has driven a setup like that says it sucks all the time, hence why a few companies started making custom length rods to being compression ratios back up to normal, non absurd levels

But if you look at the 10:1 numbers, they are much better (and what the typical b/d series setups run now as far as compression ratios, 10-11:1 on pump) with 10:1 you get a 4% increase in efficiency, this might not sound like much but its a huge difference, car will get better mpg, actually run like a normal car out of boost, not to mention higher cylinder pressures means more torque... if you were to take two identical setups, one 8.5:1 and one 10:1 and then toss them on the dyno, the 10:1 motor would make more power and torque everywhere and that's no lie

Here's another chart showing CR vs efficiency



You can see, a 3.7 (basically 4%) rise in efficiency.

 

So after some more digging and revision, does this have the looks of being able to hit 600?

B18a1/gsr head
Ferrea roller rocker setup
Bisimoto forged rods
Arias 12:1 pistons
Stock crank
Sleeved
Gsr oil pump & water pump
Bisimoto stainless +1mm intake and exhaust valves
Bisimoto valve spring/ti retainers
Shelley inc front mount turbo manifold
Custom intake manifold
ID 1500's
Aftermarket cams/gears
Tuned with demon/Neptune p28
Running e85

 

My responses are in bold

 

Sorry,i want clear, its a1 block,gsr head.
My use of bisi products is spawned from liking their products. I've used some of their products in na d series, figured id give it a try for boost a well.

The Shelly was a typo. I meant sheepey. I was planning a custom cooler, i don't mind the extra work, i like the idea of bring able to make it fit exactly as i want.
Plus, front mount looks good.

I haven't decided on the sleeve manufacture.its one any better than the other?

The intake manifold is kinda like the intercooler. I enjoy fabrication, and like to tinker around. If it made 10 more peak hp, it'd have been worth it to me.


My logic behind 1500 was most of the 5-700hp builds i was looking at run 1000's, and they all claim to be on c or q16.so if i require 30% more fuel for the same power level, 1500 would allow me to keep the pulse width low, trying to keep duty cycle down. Is that a wrong train of thought?

A far as the cam goes, I've been reaching more, and have decided i need to do more reading about turbo setups before i decide on the cams/turbo

The crank will be my stock ls

I didn't specify the fp because i kinda figured that would be a given. I intend on a high flow drop in, plus an inline possibly.

Are there any fundamentals here that I'm just plain wrong about, or would be better if done a different way?

 

Something in the 1600cc range would be great, but there is no such thing as an ID1500, or even 1600 for that matter. Your options are either 1000cc or 2000cc+
http://www.injectordynamics.com/injectors.html

 

you can always have an injector shop do a set of custom injectors to whatever flow requirement you need. theres a guy near me who works out of his garage and does some impressive injector work. he has all of the proper equipment and such and is very affordable, we've given him multiple sets of bosch ev14 injectors off our ls7 to flow/clean/balance and make them slightly larger... his modified injectors also have beautiful spray patterns... ive seen some reworked stock injectors from some companies that have the shittiest flow pattern i've ever seen

so don't limit yourself to a "shelf" injector, someone can make you exactly what you need

 

So clearly big fail on my part, i didn't actually look to see what sizes id made, just made an assumption. Am i right in theory though that its better to overshoot slightly of what you need fuel wise, then just dial back pulse width?