mudko3

Anyone know how this would run? and would it out perform a regular ctr?
just looking at N/A options. know it couldnt rev as high

A friend and i were chatting about how this setup would be if built correctly

slomofo

iTrader: (1)

Your questions all depend on how hard VTAK hits in third gear. CTRs came from the factory with m4d tyt3 third gear VTAK. The b20 is m4d tyt3 incapable, so you'd need the actual B16B longblock or even a B18C5 to achieve this. Now if you were to somewhow retrofit m4d tyt3 to your B20 block (IDK how you'd do this), then yes you would be able to smoke a CTR like a cigarette.

Schister66

It would not be nearly as fun as the B16b. The b20 has a much longer stroke making it less rev-happy and not as responsive as the B16b. If you were to mate the B20 to a CTR tranny, it would not highlight the strengths of the B20 (aka torque, not revs). If you are set on the idea, your best bet is a GSR tranny, as its longer than the CTR, but not quite as long as the LS. The CTR/B16B head on a B20 would work just fine

B16b:
-short stroke (77,4mm)
-loves to rev
-no torque (becuz B16)

B20:
-longer stroke (89mm)
-doesn't rev as high (7400rpm factory) and wont rev as quickly/readily
-"lots" more tq

NotARaCist

iTrader: (1)

That's not quite how it works in the real world, Schister. The shorter gearing and FD of the CTR transmission means better torque multiplication, means better power delivery. It doesn't need to "rev out".

Also, the lack of RPM from a B20/LS block is easy to fix - ARP rod bolts.

JoeBlue

Still doesn't mean that wasting money on parts because they are Type R is worth it. The GSR head is far better than the CTR head in this case and it's cheaper. The cams, maybe they are worth it, depending one what is done to the head, but at that point I would just be looking at Pro 3's instead... Might as well go for something better if you are already spending that much money.

I don't think the tranny is worth the cost either. Sure it has an LSD from the factory, but we all know that the factory LSD is not exactly the best one suited for all applications.

I am willing to bet a B20 shaved head and a good clean port job with 404's and a B16a tranny with an Mfactory LSD would be faster in a straight line. Obviously cost far less as well.

NotARaCist

iTrader: (1)

GSR head "far better" than the CTR head? How do you figure? The CTR head flows better. The only area where the P72 head "excels" is in a slightly higher CR, but you can easily deal with that with some forged internals. Besides the fact that Junk2 hardware is just that - junk - putting Pro3's on a stock CR motor is painfully stupid. You need a bump in compression ratio to even begin to make them worthwhile. Also, $700+ for some improperly matched cams, that would be a poor selection for the motor, that are made by a **** company? And you're calling a CTR transmission a waste of money...

$600 for a GSR transmission in good shape, plus $700 for the MFactory LSD would leave you break-even on the cost of a CTR unit. Add in the cost, time, and effort of installing the LSD, and it just makes more sense to use a known good CTR transmission.

JoeBlue

Flow only really matters at high RPM, everywhere else the higher compression given by the smaller CC GSR head is better than running a raised dome piston that requires more skirt area to be stabilized. If this is an N/A only build as it seems to be, the smaller CC chamber is more important. The amount that the CTR head flows over the GSR head is rather insignificant. If this is a stock block B20 without higher comp internals, then the OP should just spend the money on a JDM GSR and be happy with that...

If it's a build with new pistons then the GSR head is still ahead as the smaller chambers are already set up for high compression without a ridiculously high piston dome. For the cost of the CTR head you could get the GSR head reworked to out flow the CTR head and still have the smaller chambers which reduce the piston height needed and makes certain things a little more wallet friendly to obtain. Like over 200WHP is easier with the GSR head. The primary issue is that for the cost of the CTR head you could get the GSR head reworked to out flow the CTR head and still have the smaller chambers. If you are sticking with off the shelf pistons for a B20v setups you can easily hit 12.5:1+ with the GSR head. The CTR head will require some dicking around and work to find out what size pistons you need, and likely some customs ones. That pushes the cost up higher. This is bearing in mind you can even find the CTR head that is not goat-fucked already.

Also notice I said B16a transmission. I see those going for around $500 used here. We are talking about total end cost of the whole setup. The LSD doesn't have to be the Mfactory one, it's a matter of picking the LSD that fits the use of the vehicle. If it's a street driven car then the OEM LSD works just fine.

There's a point where some parts that are available matter, and there are a few more instances where you really should reconsider whether spending that much on an obsolete design is worth it. IMO I would not be spending that much money on a setup like this when you can get better power out of something cheaper. Like that B20 setup I rattled off. It's a known build with known limitations and proven power capability.


He never specified what the SCR was going to be in this setup. So until he defines out the rest of the build we are actually just bench racing, which is fine by me. I can bench race all day, I have time. What are the goals and the usage restriction on this build, without that we might as well be arguing out the best way for the OP to waste the money he likely doesn't even actually have.

Schister66

I'll concede the torque multiplication aspect of this, but as an overall platform, I would still prefer a straight B16b to a B20/vtec with a CTR tranny. There may be more torque with the b20, but the B16b would be livelier (sp?) platform by comparsion, especially when mated to the CTR trans.

JoeBlue

What do you mean by livelier?

B serious

iTrader: (1)

There's no replacement for displacement. So the 2.0 VTEC will make more power at all times in the powerband compared to a B16B.

I wouldn't do the CTR trans unless this is a road course track car. The GSR trans would make it much more usable.

A good condition GSR trans is $350ish. I sure as hell wouldn't pay more than $400. You can buy a JDM SIR-G LSD trans for $600-700.