CA18 stock cam limit ?

Discuss topics related to the CA18DE and CA18DET series engines.
dash
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CA18 stock cam limit ?

Postby dash » Mon Mar 12, 2018 8:17 pm

A stock 1st gen 4G63 revs to 8500rpm, 600hp
short runner intake manifold/bigger than stock plemum + quality valvesprings + header + holset HX35(~40psi)
A dinky 4AGE stock cams(with 7AF/1.8 bottom end) revs 8000rpm, 500hp +
short runner intake manifold/bigger than stock plemum + ?valvesprings? + header + GT35(32ish psi) + standalone

somewhat similar recipe to me
could the big turbo hotside, be uncorking these motors allowing em to breathe & rev like that ?
so basically cams would increase VE aloowing same numbers, but at less boost ?
to get up there, I thought aftermarket cams were mandatory


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float_6969
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Re: CA18 stock cam limit ?

Postby float_6969 » Tue Mar 13, 2018 3:58 am

Cams are never mandatory. Cams dictate the shape of your power curve, for the most part. I suppose at some point, you would hit the maximum flow rate for a given duration and lift, meaning more boost wouldn't make more power. What happens with cams is they allow the engine to breath better (increased VE) at higher RPMS. Anytime you shift VE to a higher RPM for a given engine size, you have the POTENTIAL to make more power, because you're moving more air.

So here's your example;
(these are made up numbers to illustrate my point)
Stock cam CA, EFR7163, makes 450whp, 30psi of boost, at 6500 rpm
264 cams, 8.5mm lift, EFR7163, 500whp, 30psi of boost, 7000 rpm

Obviously it's way more complicated than that, but you see my point.

But, like with everything, there's a trade off. Any increase in lift or duration is going to hurt lower RPM performance. So then it becomes a balancing act. There's a reason you don't see high lift/duration cams on street cars. It makes them really hard to drive, they idle poorly, emissions are crap, etc.

dash
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Re: CA18 stock cam limit ?

Postby dash » Wed Mar 14, 2018 2:55 am

Since it took all these years to see hi strung stock cam builds(for me at least)... most probably considered cams a necessity?
https://www.youtube.com/watch?v=vcGTYwzxQp0
http://www.dsmtuners.com/threads/holset ... hp.490819/

seen more than enough stock cam examples HP top out: 4AGEs ~mid 300s, DSMs ~mid 400s, CA18s ~400
Just figured the stock cams held em back, but I guess not
Still not sure on what valvesprings in the 4/7AGE

Just curious about the effectiveness of: that intake style - a big enough turbine hotside(+ header) - and valvesprings
in opening the door to 8000rpm & 500+ hp atw. A stock cam'd 550+ hp CA18 perhaps ? :chuckle:

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Re: CA18 stock cam limit ?

Postby float_6969 » Thu Mar 15, 2018 3:00 am

I'm pretty sure Boost Boy built a 500whp completely stock CA like 10 years ago. (I think it had been rebuilt though). It's doable, but it's not the most effecient way to go about it. The CA is so weak below 3K, even with a stock turbo, that I haven't noticed a huge loss in power down low, even with 264 cams. And I'm sure I could make the same power I was making on stock cams, but it would have taken more boost. Making the same power on less boost is ALWAYS good thing, as long as there's no major tradeoff.

dash
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Re: CA18 stock cam limit ?

Postby dash » Fri Mar 16, 2018 1:36 am

boils down to 'how effective' either component is, vs the goal I suppose
Gotta dig up some old threads to see 'cams added' torque curve differences. Photosuckit probably killed em all
I noticed every hi strung stock cam build r done by those very experienced with the powerplant
Our quickest street starion 2.6 clubmember went mid 10s ~99. Stock cam drove & ET'd best of all he tried
I can recall Ivans Nissan ka24 cam thread from freshalloy way back
A rolla clubmember replaced his built/cammed turbo 3TC, with a turbo stock unopened 2RZ. 5spd daily driver ET 9.8sec, 37mpg, unmatched tq
these kinda feats.... certainly grab my attention - lol :chuckle:

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Re: CA18 stock cam limit ?

Postby float_6969 » Fri Mar 16, 2018 2:48 am

Exactly. It's never really simple. It's how all of the components work together. If it was easy to make a good combo, everyone would do it, LOL!

And you're right. The Photosuckit fiasco has killed all of the forums. Why they though people would pay exorbitant amounts of money for hotlinking is beyond me. What's stupid is that if they'd made the price reasonable, I would have paid it. Some money is always better than no money.

Awesome things can definitely be done on stock cams. The question is, as always, what would it have done with cams?

dash
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Re: CA18 stock cam limit ?

Postby dash » Fri Mar 16, 2018 9:49 pm

totally agree..... n combination is the key, no doubt

yeah, forums were already on life support (especially these older platforms). Such a wealth of info..... such a waste
I wouldn't b at all surprised if FB bought or paid photosuckit to pull the plug (why it aint about da $400 imo)
Flushing out the ward, channeling the rest of traffic that way
Leaving only a handful of us stubborn sweepers here to turn out the lights :biggrin:

Buddyworm
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Re: CA18 stock cam limit ?

Postby Buddyworm » Wed Jun 13, 2018 10:47 am

There are gains to be made porting the head and using big intake runners with stock cams. Big turbines pay dividends in lower exhaust backpressure and thus higher VE.

With good enough fuel you can always push more boost into it, but as torque starts to fall off in the upper RPM you eventually hit a point where the additional RPM aren't worth the power produced. So the real question is what the torque curve looks like and whether it's worth it to rev that high vs. grab another gear.

dash
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Re: CA18 stock cam limit ?

Postby dash » Sat Jun 16, 2018 5:55 pm

Definitely wanna push the stock cams.
Another uncommon practice by a few veteran uk members was to run an intake cam with more duration than exhaust
Impressive torque curves.... something else I'd try. Gotta explore the science behind it. Most old school single cam turbo grinds

were like that, powering some hella fast cars

No plans to ever take the CA18 beyond 8000rpm or 260-268 hyd cams, using a midsize turbo (5557, 20g, 50trim T04E)
Turbo sized right on a 'good' diy manifold, should spinup early for a 'broad enough' street car tq curve

A few sxoc very impressed with gains simply from diy intake runner/port match (on the 4 port)
Runner size fine, but short with bigger plenum improved top end. Someone gave me a 'Greddy type' SR20 unit I'll mod for the CA18

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Re: CA18 stock cam limit ?

Postby Buddyworm » Wed Jun 27, 2018 1:23 pm

Seems to me you usually see longer duration on the intake side on oldschool turbo setups when the builder is using a restrictive turbine housing to spin the turbo up asap. Short exhaust duration minimizes reversion due to the higher exhaust backpressure, theoretically.

Depending on your way of looking at it it's kind of a bandaid. Modern turbos with lower rotating assembly mass and newer turbine housing geometry make it so you can reach your target spool RPM with lower backpressure vs. older tech. Minimizes the need for split duration cam setups.

Lower backpressure allows longer duration and more overlap before reversion starts choking off torque.

dash
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Re: CA18 stock cam limit ?

Postby dash » Fri Jun 29, 2018 5:54 am

yeah, the ca18s with intake cam-only swap ran T28s.... and the impressive torque curves got my attention
Probably their intent. Fatter tq band, from a quicker spool makes sense. Perfect daily driver

bandaid... compromise...? Like water/meth escorts many into the 'monster zone'. Whatever it takes, eh.
For comparison, here's two more stock head stock cam stock valve 1.8s
https://forum.miata.net/vb/showthread.php?t=224306
http://www.clubprotege.com/forum/showth ... 0-tq-33psi

500hp bone stock 1.8 escort relatively low 370 tq, perhaps from bigaz 62 slow spool. Not a particularly efficient setup either

The miata is another story. Good spooling smaller 50 trim t3/t4 @ 500hp, mid 400s tq on 93 pump + w/m inj
Pretty much same recipee as DSM & toyota 1.8 above - short runner intake & header. Fresh valvesprings with 10psi additional pressure
Built bottom end because BP rods r a timebomb (bend) ~350ish ? once u 'load' em up.
In another thread, regrind intake cam added 38hp, then 24hp more from exhaust cam swap
I believe he upgraded to 35R and lovin it (just like boost_boy has been sayin -lol)

Quite a few 5557 n 5558 ca18 and miata 1.8 street monster combos out there to study/copy also.
cool one here: http://www.roadkill.com/fuel-seeking-st ... zda-miata/


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