crvtec vs crv b20b

[Goldberg]

Hey sup guys new here. So I know a little bout cars not a WHOLE bunch but some. Now I think i decided to do the crvtec engine for my car and have sorta just started researching and wanna find out as much as i can. I was wondering if anyone here could give me some info or help me out on what stuff i should and shouldn't get. Thanks. Pm if you want to really help me out lol.

[rage2]

If it was my money, I'd do a CRV Turbo, cheaper, more powerful :).

Unless you have a reason to go NA, I'd forget about the B20Vtec.

[ecstasy_civic]

Ya I agree with Rage, B20 is a strong motor and good motor for turbo.

[Goldberg]

ohh and sorry i was planning to turbo it to lol

[ls/vtec-crx]

Just go with a CRVtec turbo. It will make more power than a regular CRV turbo. With the CRVtec turbo you gain way more top end power than with the regular CRV. You can easily run 275-325whp with a bone stock CRVtec turbo. We did one in a 94 integra gsr at the beginning of the year and got 280whp @ 8psi on Toma's Mustang Dyno.

CRVtec is the way to go. Make sure to use a good head gasket because crvtec's or ls/vtec's are known for blowing stock honda head gaskets.

[rage2]

On pump gas, in theory, CRVTec vs CRV turbo should make relatively the same power, with the CRV turbo making a bit more torque on boost, and CRVTec turbo be peppier off boost.

With lower compression ratio of the CRV, you can run slightly higher boost pressure to make more torque, and max power at lower rpm.

With the higher compression ratio of the CRVtec, you make less torque because you have to run lower boost, but you make the same HP because you can push that same amount of TQ to a higher RPM (more power up top).

Of course, on race gas, it's not gonna matter, and the limits is the strength of the block, which will be the same on both setups :).

So the answer is, depends on your budget. Low compression CRVtec with a built block will probably make you the most power on pump gas.

[Goldberg]

Well what i wanna do is first buy the b20 block and build it before i do anyhitng. Like resleeve it pistons retainers etc etc. Then when i finish the block itself. Park my car and work on the head. New valvetrain, cams, etc etc. I just need some info on what would be the best stuff to use. I will probably use crower cams vallves for booost and then je pistons spec for boost. I want this to be able to be boosted alot but still safely. But i can someone tell me excactly what year and such on the block. Cause i ain't quite sure which one i need yet.

[ls/vtec-crx]

In Theory, on pump gas adding more boost to a crv just makes it more siceptive to detinating. Why not just add a vtec head run less boost and make more power. Torque you will definately not lose on because when you add the vtec head it will make more torque because off added compression and better head flow which will probably amount to earlier boosting which will add even more torque down low.

Adding a b16 vtec head to a crv on raises the compression from a 8.6:1 to a 9.0:1.

Budget is definately what it comes down to. But I would actually say the a fully built crv block with stock vtec head will make way more power than a fully built crv block with crv head.

But that's just my two thoughts.

[Goldberg]

Well the fully built block is not gonna get a stock b16 head. Like i said i gonna build the block on the side thorugh winter or next year. Then park my car take the head off and build it up and put the two together. So won't that setup along produce good hp and good tq. Then i will boost it. So hopefully when i all done everything will be built to the titties. Money isn't to bad my dad knows the owner of a machine shop really really well so all i have to really do is get the parts give it to them and its done. Ohh and how much boost you thnk i could run max while being safe with the whole setup?Your probably asking fuel management and such. I also gonna do all that also, plus new ecu and all.

[ls/vtec-crx]

We are actually building three fully built CRVTEC turbo car's. With a fully built crvtec motor and a decent turbo kit you should get about 300-360whp on pump gas. I will let you know what our setup runs in the next week or two. We've got a 92-95 Civic HB and here is his build:

B18B block
Darton Sleeves
JE 9.0:1 Compression 84mm(crv)
Eagle Rods
Z10 Crank Girdle(for your main caps)

B18C1 head
Port and polished
Crower Stainless Valves
Skunk2 Valve Springs
Skunk2 Retainers
Hondata Intake Manifold Gasket
JG Edelbrock intake Manifold

B18B Tranny (LS)
ACT Clutch Kit
ACT Flywheel
Quaife Limited Slip Differential

And that would be your basic full motor build.

[rage2]

Originally posted by ls/vtec-crx
In Theory, on pump gas adding more boost to a crv just makes it more siceptive to detinating.
Yes, assuming CR is the same as the CRVtec.

Originally posted by ls/vtec-crx
Why not just add a vtec head run less boost and make more power. Torque you will definately not lose on because when you add the vtec head it will make more torque because off added compression and better head flow which will probably amount to earlier boosting which will add even more torque down low.
With higher compression, you'll make less torque under boost because of preignition limits of pump fuel forcing you to run less boost. CRVtec makes up for it by allowing the lower torque to pull to a higher rpm, thus creating more hp (hp = tq*rpm/5252).

Off boost, the higher compression motor WILL give you more torque and help spool faster, but on boost at WOT, it'll make less, assuming tuning targets are identical (same EGT/no detonation).

Originally posted by ls/vtec-crx
Adding a b16 vtec head to a crv on raises the compression from a 8.6:1 to a 9.0:1.
Actually, 8.8:1 to 9.3:1

Of course, this is all theory... I haven't built either combinations, so I might be way off. But I've tuned legendboy's B18B with the same head/cams as the B20B, and I think if pump gas is the target, the B20B vs b20vtec will provide the peak power, with the b20vtec having a more streetable powerband.

[rage2]

Originally posted by ls/vtec-crx
We are actually building three fully built CRVTEC turbo car's. With a fully built crvtec motor and a decent turbo kit you should get about 300-360whp on pump gas.
Hrm, I must be missing something here. What's changed to address detonation on pump gas? Without changing compression ratio, displacement, or rev limit (and I mean a really high rev limit to hit 360whp), you're going to run into preignition limits of the fuel, regardless of how strong the block is.

Assuming 280whp@8000rpm is the pump gas limit of a crvtec motor on pump gas, it means at 8000rpm, it's making 184tq. To make 360whp, you either have to make 237tq@8000rpm, or 184tq@10275rpm (or somewhere in between).

BTW - for anyone else reading this thread, this shows you that there is no replacement for displacement... on pump gas anyways :).

[redline]

Originally posted by rage2

Hrm, I must be missing something here. What's changed to address detonation on pump gas? Without changing compression ratio, displacement, or rev limit (and I mean a really high rev limit to hit 360whp), you're going to run into preignition limits of the fuel, regardless of how strong the block is.

head design, the vtec heads have way better designed combustion chambers.



BTW - for anyone else reading this thread, this shows you that there is no replacement for displacement... on pump gas anyways :).

how much tq. do you need in a fwd car? In my car, my first two gears are useless @ 10 psi and all these b20 are going to make more tq.

[rage2]

Originally posted by redline
head design, the vtec heads have way better designed combustion chambers.
Yea, I already accounted for that, which is why the CRVtec makes the same peak HP at a higher RPM, but with lower torque from lower boost due to compression ratio.

Originally posted by redline
how much tq. do you need in a fwd car? In my car, my first two gears are useless @ 10 psi and all these b20 are going to make more tq.
haha, there's still 3rd, 4th, and 5th gear :D.

[ls/vtec-crx]

Originally posted by rage2


Assuming 280whp@8000rpm is the pump gas limit of a crvtec motor on pump gas, it means at 8000rpm, it's making 184tq. To make 360whp, you either have to make 237tq@8000rpm, or 184tq@10275rpm (or somewhere in between).



The full gsr that we did was 355whp@7600rpm and 254tq@6800rpm. and if we were to use his turbo set up on a fully built crvtec it will make way more torque than 254 but should have about the same hp level.

I give up. I guess we'll see what happens.