ca in a datsun 1200

[bobs1200ca]

Ok I'm new to this forum, I have a 73 dastun 1200. and looking for info on a CA18Det for use in a datsun 1200 for auto crossing. and what racing transmission are available. I have beed auto crossing my car many years current Classing is EP in SCCA. Moving to Xp with engine swap, figure I need around 350 to400hp to be competive. how much work is needed to obtain theese figures with CA18DET. part recomendations and suppliers needed. also will be selling drive train from car. A12 with a14 crank Rebello built engine and a Dan Hall modified 60series Trans with webster gears and dog ring sycros.

Thanks Bob

[float_6969]

No real off the shelf racing transmissions available. The stock transmission is good to 400+hp, but that's in street conditions. I'm not sure how it would hold up road racing. You might have to fabricate an adapter plate to use an off-the-shelf transmission.

350-400hp isn't too much trouble on the CA18. As long as you have a good condition motor, it can be done with bolt on's and a ecu tune/standalone. For a racing situation, I would recommend a standalone EMS though.

As for specifics, you'll need some sort of EMS or the ability to chip tune the stock EMS, MAFS, injectors, turbo manifold and turbo, and turbo. This would get you there for the 350HP mark. Over that you start to run into issues with the stock intake manifold being restrictive and the un-even flow of the manifold starts to become an issue (#3 cylinder tends to run lean). It would also be a good idea to do a basic port job and gasket match as well. The stock ports have a decent amount of shrouding and the ports don't line up well.

Hope that helps.

[bentvalves]

dont need a turbo manifold to make 350whp. I would recommend staying with the glorious cast iron, divided pulse manifold. paired exhaust pulses pwn.

[float_6969]

You CAN eek 350whp out of the stock manifold, but you'll be hard pressed to hit 400whp with it. Even if you do, I would be willing to bet that stepping up to a larger flanged, paired manifold, will yield more power.

[bentvalves]

you will yield more peak power with a tubular manifold, but more area under the curve is attainable with the stock manifold. more area under the curve is what you want unless you are circuit racing.

[bobs1200ca]

thanks for the imput guys, Here are my starting plans wiseco pistons with k1 rods, lightened crank, chrome molly flywheel arp head studs and main bolts rods already come with arp bolts, tubular exhuast manifold with top mount turbo clean up of ports in head titaium valves and retainers upgraded valve springs. intake, turbo size, injectors yet to be determind. not sure on ecu yet but will be speed density system with stand alone. I am familiar with having apeaky engine 1400 i have in car now is fully built it has 145 at wheels and car weighs 1400lbs with ca car will need to be around 1750lbs

http://datsun1200.com/modules/myalbum/p ... ?lid=21443

[float_6969]

you will yield more peak power with a tubular manifold, but more area under the curve is attainable with the stock manifold. more area under the curve is what you want unless you are circuit racing.

I'm quite aware of this. I feel like you're missing my point. I never said to get an equal length tubular manifold that wasn't paired. In fact, I would strongly suggest staying with a paired manifold, and even better, a twin scroll turbine housing. (this is what I've done with my turbo setup, and I'm running a T4 turbine). My point is that to get to 400whp, and to try and move that much exhaust through a T2 flange is going to be limiting. It's do-able, but not the most efficient way of doing it. AND, AFAIK, you can't get a twin scroll turbine housing in ANYTHING with a T2 flange. It's because the flange is so small, that adding a divider cuts the area down so badly that it wouldn't be able to flow much exhaust, which would limit it's peak horsepower. I understand that area under the curve is very important. But only to a certain extent and to what application? He's autoXing, so he does need as much power band as possible. This means bottom end AND top end. That T2 flange is going to choke out at 400whp. That's a simple fact. He could get the same bottom end response, and increased top end power, from a T3/T4 hybrid, and get a fully divided exhaust setup (manifold AND turbine housing), which would ultimately yield him more area under the curve than what he would get from staying with the stock manifold and going to another T2 flanged turbo with a single scroll housing.

thanks for the imput guys, Here are my starting plans wiseco pistons with k1 rods, lightened crank, chrome molly flywheel arp head studs and main bolts rods already come with arp bolts, tubular exhuast manifold with top mount turbo clean up of ports in head titaium valves and retainers upgraded valve springs. intake, turbo size, injectors yet to be determind. not sure on ecu yet but will be speed density system with stand alone. I am familiar with having apeaky engine 1400 i have in car now is fully built it has 145 at wheels and car weighs 1400lbs with ca car will need to be around 1750lbs

http://datsun1200.com/modules/myalbum/p ... ?lid=21443

Stay away from the Wiseco pistons. Due to their design, they can't accommodate the piston oil squirters that are in the block. I would recommend CP pistons. Myself and many others use them and have great experience.

You don't need rods for the power level you're at. Put some ARP rod bolts in the stock rods and you'll be fine to 500HP.

Make sure the exhaust manifold is a divided manifold and that you pair it with a twin scroll turbine housing. TRUST ME, you'll be glad you did. I swapped from a single scroll, to a twin scroll housing and it made a huge difference. Not only does it spool faster, but the transient response is WAY better. Pair that with a new BB center section and your response would be nearly instantaneous, which is obviously something you want in AutoX.

You've mentioned it, but do pay attention to the ports. There is a lot of power to be had porting the head.

If you design this right, it won't be peaky at all. I'm in the same power range as you, running a small T4 turbo, and I'm fully spooled by 4K. I was running up to 8K with my T28 and stock cams. With the bigger turbo and HKS cams, I'm expecting to be able to go even higher. If done right, this engine doesn't have to be peaky.

[bentvalves]

dude.

im not sure ca18 and T4 even belong on the same page, nevermind paragraph.

your fully spooled by 4k rpm because your static compression ratio is through the roof.

remember most of us are running 8:5 to 1.

[bentvalves]

and who makes a divided pulse tubular manifold for ca18 if you don't mind me asking?

[bobs1200ca]

dude.

im not sure ca18 and T4 even belong on the same page, nevermind paragraph.

your fully spooled by 4k rpm because your static compression ratio is through the roof.

remember most of us are running 8:5 to 1.

but when does compression effect when a turbo is fully spooled up!!! The engine is an air pump it pumps the same volume regardless of compression ratio at a given rpm. volume will increase with more inlet pessure but not compression since there is no compression with exhaust valves open

[float_6969]

dude.

im not sure ca18 and T4 even belong on the same page, nevermind paragraph.

your fully spooled by 4k rpm because your static compression ratio is through the roof.

remember most of us are running 8:5 to 1.

Why doesn't a T4 belong on a CA? The turbo kit I'm using is mostly un-modified from HKS. TheMadScientist ran this kit on his COMPLETELY STOCK CA18 and was spooling up by 4500RPM. It was spooling at the same RPM on my car. The reason I'm spooling at 4K is due to the twin scroll housing. Not the high compression. If anything, high compression would LOWER spool. With all other variables kept constant, if you increase compression, EGT drops. The displacement of the engine doesn't change with compression, so I'm not moving more air. The high compression gives me more power off boost. This is one of the reasons Diesels have such low EGT's and have trouble spooling turbo's. They have REALLY high compression, and REALLY low EGT's.

and who makes a divided pulse tubular manifold for ca18 if you don't mind me asking?

I've never looked for that kind of manifold, but from a fabrication standpoint, any competent machine/race shop that could build a set of headers, could build that manifold.

It seems like you're taking offense to me suggesting a different route than what you're suggesting. I feel that I've made it very clear that it's possible to make 350-400whp with the stock manifold. My personal opinion is that with a slightly larger turbo (t3/t4 hybrid) you could make the same power, with less boost, less back pressure in the turbo manifold, better top end power, and little loss in low end power, making for a more efficient system.

It's like saying that you don't need cams to make 500HP. I'm sure I could make 500HP on stock cams, but how much MORE HP could I make by changing cams? Most engine modifications don't make fixed HP increases. They make percentage increases. It's like doing a port job on the heads of an engine only making 200hp. It takes about 10-12hrs to port the CA18 head, and will gain you around 10% more power. That's a lot of work 20HP. It's easier to run 2-3 more lbs of boost and make the same power. But when you're looking at 400HP, now 10% more power is 40HP. I think most ppl (including myself) are willing to spend the 10-12hrs required to port the head and gasket match it for 40HP. Sure you could run another 4-6psi and make the same power, but it's quite possible that at that power level, that is going to be too much boost for the size turbo you want to run, and you'll have to step up to a bigger turbo, which always means you have to give up spool speed and transient response.

The guy asked for opinions. You gave yours. I gave mine. He'll decide for himself based off of the info given to him.

[bentvalves]

I took 0 offense to your suggestion float, maybe I came off wrong with the way It was worded. Im going to have to research the compression ratio vs. boost thing before I shoot myself in the foot.

[float_6969]

No worries. Just wanted to make sure we're cool. As for the compression ratio vs. spool up, read the second paragraph here; http://www.sdsefi.com/techegt.htm

[mdb4879]

So as I was reading this I had an epiphany. I never understood exactly why higher compression made more power until now.

Having higher compression means the combustion chamber has a smaller volume, and because of this a greater percentage of exhaust gas compared to the volume of the cylinder is expelled. So when the intake charge comes in a greater percentage of that is fresh air rather than exhaust gas. This also means it will be cooler because there is less hot exhaust gas already in the chamber. So this will make for lower EGT's. Also the higher compression means greater cylinder pressure to force the piston down, making more torque. And the fresher intake charge may have something to do with more power as well.

Does this sound about right? I didn't do any research, it just kinda came to me and seemed to make perfect sense.

[float_6969]

This is a part of the equation as to why higher compression makes more power, but not all of it. Most of the gains come from an increase in thermal efficiency, ie, the engines ability to convert energy into work.

[tommey]

There were some dog boxes made in sweden a couple of years ago, for the CA18.
They used the stock housing but with new internals.
They were pretty cheap, around 3000 USD.
You could try a stock CA or maybe use an RB or z32 transmission and a different diff ratio to get shorter gears.

BTW, i know a couple of 380 whp cars here on stock manifold and no e85.

[themadscientist]

T04 on a CA, rediculous.



Now you will tell me some company was foolish enough to produce a kit for one, silly.



Such crazy talk.

[float_6969]

LMAO!!!! IDK, but I can tell you they did a helluva a good job on it! BTW, I've been meaning to tell you, if you've still got one of these kits around, try swapping the turbine housing out for a .58 A/R twin scroll housing. It's AMAZING. Turbo spools about the same speed, but there is WAY more power before boost comes on than with the .48 A/R single scroll housing. I haven't really gotten to beat on it much yet to see how the top end has been effected, but so far, it seems unchanged, if not better!

[themadscientist]

I need a new screw and I don't think I want to foot the bill for a ball bearing. The car will be doing on roll starts and top speed runs so I think I can get away with a less whiz-bang journal bearing and the larger housing will be put to better use. I'm thinking a simple T04S would be the ticket. The lag will help with the car's inherent lack of traction too! Durned 13s get spooky at three digits.

http://www.atpturbo.com/mm5/merchant.mv ... y_Code=TBN

[float_6969]

P-trim, and it looks like the smallest A/R on the hot side is .70 for the twin-scroll. It'll definitely spool slower than my current setup (O-trim, .58 A/R), but I'll be it'll be lit up by 5K.

[float_6969]

I'm begining to think that my .58 A/R twin scroll turbine housing is too small. I got to thinking about it, and I think that the A/R of a twinscroll housing doesn't work the same as it does in a single scroll. The problem is that I think it's measured the same, but the divider isn't taken into account. If I'm right, then the turbo behaves more like what HALF the A/R would be on a twin scroll because the exhaust pulses only ever see half of the turbine housing.

Any input?

[1200ute]

I had read something along the same lines. It was regarding something like a A/R 0.78 TS which calculated as smaller than a 0.58 single scroll. I can't even think were or when i read that but there must be info out there.

[float_6969]

Yea, after you figure the width of the divider into account, it would be even less than half. If this is true, that means I have an effective A/R of < .29!!! I'm still trying to find anything definitive, but info on actually sizing a twin scroll seems to be scarce.