What in the hell are you talking about? I had a d15b7 block, d16z6 head on my four door. Then boosted the piss out of it. Never had a damn problem with that car. And before it was boosted, it wasn't tuned, and ran like a charm. You don't need rods or a tune for a mini-me, unless it is boosted obviously.

Explain why you say that please.

 

I dis-agree.

Mini-me swaps can be very reliable. For it to run correctly, of course you would need a tune. But that is because there is no stock Honda ECU that has a basemap for that particular setup. I had a mini me and it ran great for as long as I had the car, "Important" has had several mini-me's and they've all been sucessful without a tune.

However, to a certain extent..when you do the mini me, it raises the compression significantly. When you raise the compression, it will require more fuel. Any engine with high compression without a tune will run lean, detonate and fail. Doesn't have to be "just a d-series". I personally have seen a D16a6 with a D16y8 head, just bolt ons...yield 106whp and 101lbs wtq. That's more to the wheels than a stock B16.

I say, do a mini me. It's fun to drive and is pretty quick to be an all-motor single cam. I'd perferably use 93 octane with a mini me, if you don't already use that in your car since the higher octane will slimmin the chances of detonation. I would go with a D16z6 head, convert to obd1 and run a p28.
I'm only suggesting convert to obd-1 and run a p28 because, it is a VTEC Ecu, has the cam timing for that head as well as I know you have a d16y7 and it can get rid of that annoying 3-wire sensor on the throttle body. Lastly, get an ex tranny! Good luck with what ever you do.

 

mmmm, Vtack!
my favorite noobie line is- vtack feels like a mini shot of nitrous...
haha

 

So please explain to me how gearing affects an ENGINE'S power output. Gearing only affects how that power is used, not how much power it makes. The gearing takes advantage of the usable power band, but it can't dictate it. Don't confuse power output to the wheels from power output from the engine. The engine doesn't care what it's connected to.

Yes, which is why it makes less power at high RPM. It's just math, and math doesn't lie. And obviously it's from the cams, yes.

If you look closer, you'll see I made a generalized assumption to illustrate that HP is related to RPM. However, nowhere did I mention an LS or a VTEC engine in that example, or their torque curves.
I'm sure you don't believe that I think LS and VTEC engines have the same torque curve.

 

When I was 16 I had a CRX HF and was planning a B16 swap. Then I found that torque is what I needed to win races. After that, I was pointed to the Mini-Me build. After tons of research on D-Series forums and talking to locals with the build.. well.. an untuned build went *POP* after about 3 months.

There was even an account of a build with shot-peened stock rods that failed miserably.

After all of that research and talking to people that had that build I decided to wait for a B-Series instead of risking my tiny wallet.

There is an advantage to the Type-R head.. the mild port and the cams, retainers, springs, ect. A B16 PR3 head casting would be the same with a mild port and those parts.

The P72 GS-R head would be ideal for a boosted application due to the valve-angle and cam design. There are some records for a stock B18C GS-R with a turbo and a niice tune running 300 HP to the wheels.

By now we should all know HP doesn't mean much.. torque is where it is at if you want to win races.

The PR3 casting flows much better than the P72.. so for an NA build the PR3 would have the advantage.. turbo, the P72 would have the advantage.

E

 

i'm gonna have to put up a b.s. flag on the sohc>ls swap comment. the last sedan i built was a 1994 civic dx sohc. the guy went a 1998 ls with cai/header/exaust with a decent exedy stage 2 clutch and gs-r tranny. the car was full weight/full interior with 17" racing hart cp-10's. sohc, the best times were high 15's, ls best times were mid to low 14's. the ls motor is like the small block chevy of honda. it's perfect for boost,makes a lot of power,without spending all the money needed to build a vtec motor for boost. now i have owned both,including my current gs-r,but i still prefer the straight ls or b20/ls head and cam combo(8 more horses btw!!) for boost applications. to each his/her own on motor builds,but the ls has far proven itself as a good boosted motor.

 

I think specifics are important. Anyone who doesn't realize HP is directly related to RPM doesn't need to be improving anything on their car. However, many people don't realize what VTEC is, how it works, or what it does. Nor how it compares with a standard cam.

Simply put, the Camshaft is the heart of an engine. It tells the valves when to open and close in relation to the piston. It is the single most important piece of a motor, in terms of performance. The camshaft dictates useable RPM ranges, idle quality, pretty much every characteristic of the engine.

Obviously, you're a bit smarter than most. You have a reasonable grasp of that concept. What does the trans have to do with it? If the trans ratios are such that you have a useable 2 gears for a 1/4 mile, and you're idea of fast is how quick it'll go in the first 1320 ft, then you better have a LOT of un-useable power to push it early on with, along with a motor that makes 90% of it's peak torque throughout the entire powerband.

You're right, it has nothing to do with motor-specific output. It has everything to do with actual performance potential of the vehicle. PERIOD!

Turbochargers add a whole other dimension. Properly sized, regardless of cam profile, they can literally push enough air to still maintain the torque curve at very high RPM's, so long as surge doesn't become an issue. That means, that you could turn the motor 15,000 RPM (assuming it would stay in one piece) and it would still be gaining horsepower.

For practical purposes, we'll assume an LS versus a VTEC B-series.

TypeR cams will maintain close to 90% of their peak torque from 2000-8000 RPM. Shortly after 8000, they begin to fall off at a rate that dictates the motor won't make peak power at any point after that.

LS cams are actually rather radical. The head flow doesn't help them any. Because of the radical nature, they have very little low-end punch. They tend to run out of steam at about the same 8000, or just a hair before, but they don't make 90% of the Torque until 4500 RPM. Also, when they begin to fall off, they fall off faster than the VTEC cams, on both sides of the spectrum. Basically, it's a more "peaky" powerband. It rises and falls faster, giving it less area under the curve, and less "overall" useable power.

Other things that affect that, are head flow at various lifts, valve sizing, port design, displacement, bore/stroke combinations (which, aside from the mechanical aspect also affect the airflow characteristics due to relation of the piston to the incoming/outgoing airflow at various valve timings), rod length, and many, many other variables.


But the cam is truly the heart of a motor. It dictates the maximum potential.

As a side note:
You can gain more performance generally, in a N/A car, by matching up the proper gear ratios, tire sizes, and shift points for a motor, than from all the bolt-on mods you want to use.

Take a LS trans, and bolt it up to a B16. How's it going to run?
You'll have a 13.77 torque multiplaction from the gears through 1st. That's as opposed to a B16 Trans @ 14.2 or a TypeR Trans @ 15.45. It only gets worse from there. Even worse, the spacing on the LS is not well suited to keeping the motor in it's powerband. You'd have to have a very wide powerband to push the LS trans.

Which is easier? Getting the additional 20-25 hp needed to get the LS trans to run with a B16 trans, or putting in the B16 trans? And, given the additional 20 hp, the B16 is back with the advantage it had.

So.....

I'd take the wider powerband, and better everyday drive-ability of a VTEC setup anyday!

And, if you want to know how trans dictates powerband: You should build the motor to suit the trans you intend to use. Period! If you're going to use an LS trans, you're likely better of with a slightly milder cam, with steeper ramp angles, that will allow much better low-end torque, with a slight sacrifice on the top end. This gives you a lot more area under the curve, with a sacrifice of a few hp on the top side.

To the contrary, with a TypeR, you'd not mind a "peaky" motor, as you can keep it wound out much more easily, so a more radical profile could prove benificial.

It's not all about making motor power.....1/4 mile performance is about suspension, gearing, setup. Top speed performance may very well be limited by aero long before the motors horsepower...... Dyno performance...now that's where real racers race isn't it?

 

most of this is true^. the 99-00 si head is the exact same casting as the pr3 type r head minus the hand porting and polishing,better known as the "5000" series head. the type r motors were purpose built to be n/a motors that regularly turned high rpms, hence the coated pistons,and better sodium filled valves. the 00' si heads are almost identicle to the type-r heads,do your research. and the gs-r records are much higher than 300whp,try almost 400whp. the main problem with honda motors,is that they were not designed for boost of any kind. prime example,name a honda motor that has rods that are strong enough to make 400whp>, none i can name except for the honda sabre(vigor here) and the honda city. both of these cars were purpose built for boost. all the other honda engines were designed for gas milage/driveablity/reliablity,nothing more. i want to climb a wall when i hear some dumbass kid say,"i should make way more than 100whp over stock whp on a boosted stock motor" wrong dipshit, you should jump up and down and be excited if that happens. these cars weren't meant to have the pressure and stress that boost creates. moral is , if your going with a boosted application,spend the money to make your investment a long term investment,not a short one.

 

You bring up a very good point. As a general rule, for any given motor, built by any given manufacturer, 50% over stock power levels is the crossover point at which it's time to start replacing parts that are likely to fail. Rods and Pistons come to mind first.

If you're planning to turn more than the stock redline for the motor, and/or to turn that level for extended times, that's a good time to start looking at valve springs, retainers, valves and keepers.

Obviously, there are exceptions to every rule. The TypeR having been designed for sustained high RPM useage is a good example.

 

The PR3 casting is the same in the B16 and B18C Type-R.

They used it in the CRX, Civic, and Integra XS-i in Japan, way before the US market had the Civic Si with the B16.

They are the same casting. Different parts, and a mild port from the factory.