Themi's 1979 Honda Civic

[Themi]

Placeholder first post for my 1979 civic build.

Link to build is here:

 

[Themi]

I guess it isn't exactly "build" related but more theory-crafting. This person has done an extremely tidy job of putting a DOHC ZC into a 1st gen civic.

The big concern is that half of the engine bay is taken up by intake manifold, hence the comments on the main thread regarding RBB or 2zz intake manifold. Both of these have low-mount intake manifolds, with the runners curling over the top. It is worth noting that my ITB manifold on the Mazda was made by welding a ZL-VE intake manifold to a 4age intake manifold, both chopped off by hand with a hacksaw.

Here is one variant of the 2zz intake manifold. The 2zz has similar port spacing to the ZC, so it won't be too difficult to cut and shut the stock ZC manifold on at the start of the runners. The removable plenum that came on the corolla 2zz (but not the celica) will help with welding the lower section of runner.

Here  is the K24 RBB intake manifold: The key benefit is that it unbolts half way through the runner. This means if I modify a stock ZC intake manifold to match that first section of runner, I get easier access with a die grinder to port it out. The drawback is that these are often more expensive, and are larger than the 2zz manifolds. Additionally the K24 has much wider port spacing, so mating the two manifolds might be a non-starter.

Regardless, it will be a bit of a journey to make an intake manifold fit for the engine placement I am after. This is not something I specialize in and it is hard to find exact make/models of car for specific intake manifolds at wreckers. It might just require a good half-day of walking through pickapart to find the perfect manifold.

 

I'd love to hear anyone's ideas on this, tell me how bad of an idea it is or suggest a better intake manifold, I'm all ears!

[Honda Ass Dragger]

Turbo will need a .86 rear or go bigger Hondas love to breath a ZC/D likely moves more air than a SR20

[Themi]

10 minutes ago, Honda Ass Dragger said:

Turbo will need a .86 rear or go bigger Hondas love to breath a ZC/D likely moves more air than a SR20

Really? This is interesting thank you.

I have done some limited research and I'm wanting to get into the high 250whp on full boost. I did some googling which suggested a gt2560 won't get me there hence the gtx2860 which is expected to get about 300whp with a better spool (gtx vs gt). My "knowledge" comes from mazdas which flow like shit.

The pulsar GTX2860 Gen2 comes in a .64 or .86 5bolt rear or I can get the .82 3" vband rear housing. I don't have a big enough wallet for the real deal Garrett haha. I was thinking of the VBand .82 outlet because I dislike bolted flanges.

What turbo would you be suggesting if you had the choice?

[Honda Ass Dragger]

3 hours ago, Themi said:

Really? This is interesting thank you.

I have done some limited research and I'm wanting to get into the high 250whp on full boost. I did some googling which suggested a gt2560 won't get me there hence the gtx2860 which is expected to get about 300whp with a better spool (gtx vs gt). My "knowledge" comes from mazdas which flow like shit.

The pulsar GTX2860 Gen2 comes in a .64 or .86 5bolt rear or I can get the .82 3" vband rear housing. I don't have a big enough wallet for the real deal Garrett haha. I was thinking of the VBand .82 outlet because I dislike bolted flanges.

What turbo would you be suggesting if you had the choice?

Im currently running a XonaRotor 5757s on my B16a this is a 3071r sized turbo

With the .86 rear in getting boost at 3k and full boost by 4k 

If it was my ZC/D series id slap a G25-550 onto it

 

[Themi]

That just seems huge - I don't know if the s40-b000 will take much more than 250whp, 300 was a stretch but I figured a light car would reduce the amount of stress in the gearbox. The other issue is the sleeves - I'm running stock sleeves and not sure they'll hold much more than a 2860 can give.

Do you have a dyno sheet from the b16 by chance - so I can see the response? I'd imagine if a 3071 size can get in boost by 3k, the 2860 will be spooling by 2! This seems a bit more practical for the build, to me. Regardless I do appreciate the input, I haven't completely dismissed the g25-550 I will just need to do some more research.

[Honda Ass Dragger]

5 hours ago, Themi said:

That just seems huge - I don't know if the s40-b000 will take much more than 250whp, 300 was a stretch but I figured a light car would reduce the amount of stress in the gearbox. The other issue is the sleeves - I'm running stock sleeves and not sure they'll hold much more than a 2860 can give.

Do you have a dyno sheet from the b16 by chance - so I can see the response? I'd imagine if a 3071 size can get in boost by 3k, the 2860 will be spooling by 2! This seems a bit more practical for the build, to me. Regardless I do appreciate the input, I haven't completely dismissed the g25-550 I will just need to do some more research.

I don't have a dyno sheet as never bothered to ask for one, my motor is totally stock unopened 230,000km B16a

The biggest weakness with Honda motors and boost is the RODS they bend if there to much torque - so as far as im aware my car has been set up to run on gate pressure (3pis spring) until its make maximum torque we then feed it boost up to 7.5psi in 3rd and above
 

I was originally going to go with a 2871r however my tuner told me the car would run out of puff about 6k as the a t28 spec turbos should only be used on asthmatic shitbox like SR20s and B6/bpts

 

[Themi]

9 minutes ago, Honda Ass Dragger said:

...asthmatic shitbox like SR20s and B6/bpts

Yes, I hear this haha.

Cool as, I might keep hunting through forums and see what people have successfully run on a ZC. Lots running different td04 and td05 combinations, generally with quite large turbine housings yes. I think the D-series enthusiasts Facebook page had quite a lot of love for td05.

I think popping a block would be upsetting but yeah my rods aren't going anywhere. They'll take whatever I throw at them.