Custom camshafts: Who has serious ones?

[Steampunk]

I know a few people here have installed bigger cams.
Can you please tell me the specs you have (if it's not too secret squirrel stuff) cause I am considering getting \"Stage 4\" ones:

1.8 Hydraulic Lifter Cam Profiles, 1994-1998 engines
_Seat Duration_ Cam Lift
Stock (int/exh) 233°/254° .318\"/.339\" (8.08 mm/8.61 mm)
Stage 1L 241°/258° .323\"/.344\" (8.20 mm/8.74 mm)
Stage 1 254° .370\" (9.40 mm)
Stage 2 260° .375\" (9.52 mm)
Stage 3 266° .375\" (9.52 mm)
Stage 4 276° .375\" (9.52 mm)

With all other things being equal (I'll get an aftermarket EMS), will I encounter any problems with installing a Stage 4 cam on a stock engine?

The guy I was corresponding with said that the specs on their Stage 4 is the absolute maximum they would produce for a stock set-up, otherwise any bigger will cause spring-bind.

[Hellmun]

You realise the longer duration you run the further up the rpm band you get power. I think Bab's was making power past the redline with just the 252/256(guessing I cant' remember exactly). If your aren't running a crazy setup to Rev that far...I doubt the stage 4 is going to do you any good. The cam making power isn't the only reason the redline is set at 7200rpm.

[Alfadog]

Yep you're right, they are Tomei 252/256.

[Steampunk]

Hellmun, so if you were me, you wouldn't go past Stage 2?

I don't mind a rough idle, and pissy bottom-end.

I just want to be different and make decent power without going artificial aspiration.

[Hellmun]

Well I've started collecting bits of a turbo build... but when I was really tempted to make a basic NA screamer(I wanted to keep in just modified for club days/Super sprints)... I was going to go for something around the 262 duration mark with 10mm lift. Thinking I'd get power around the 8000rpm mark and then just get better valve springs and possibly change to solid lifters (NB8B problem) but just run upto 8000rpm. With my ECU I was hoping to hit about 105-110kw atw and hopefully with some reliability at that. Figured I might end up idling about 1200rpm but would still have a decent mid-range. The things that turned me off are just how long the engine would last, where it would die if it did (I drive my car to the track) and what else would die at that RPM as a consequence. As I'm sure CT and the other racers wouldn't talk about underdrive pulleys without them being somewhat wise. Possible breathing issues as well with a street tuned header/exhaust/intake/head. Plus the possibility the engine simply won't reciprocate well with the heavier standard pistons(there's a special somewhere on honda VTEC tuning which was quite interesting on the problem on high rpm and things they did to solve it).

Big thing for me is I have an NB8B. I needed to get inner shims machined to fit with tight tolerances, change valve springs just to run something more basic like the Maruha F-cam. So to get a small gain of 5-10kw I'm likely talking $3k+. That's doing as much of it as I can myself. It doesn't math out and I'm more torn than ever just to try and finish off the year with the car basically as is while building an engine on the side.

For you, if you have an NA8C you can literally get a Tomei cam set with shims for about $1500 and just put them in..... Babs has already done it and Irwin is soon to do it on his NB8A. Bab's even has dyno graphs so you can see where a basic cam setup takes the power band on a similar car if you search for them.

Just basically mathing it, your talking about an %18 increase in duration alone on Stage 4, without moving the maximum powerband of the engine up %18 in RPM. You'd need 8500rpm to use that cam assuming they both increase linearly. The increased lift probaly pushes it even further up. I worked out I couldn't afford to really test it on my car....

My money and same car, get the stage 2 if I'd already done exhaust/intake already (even without the ECU you might get a good gain). If it's for trackwork though you may find your money is much better spend elsewhere for laptimes. When I installed an ECU, Exhaust and intake my laptimes didn't go down much. Car didn't suddenly reach significantly higher speeds before braking everywhere. I got much more out of tyres, suspension and diff. Then even more when I started really learning how to setup the car.

[Alfadog]

Bab's even has dyno graphs so you can see where a basic cam setup takes the power band on a similar car if you search for them.

(FYI Hellmun I bought Bab's car )

[adamjp]

FWIW my NA6 has 264deg HKS cams.

Now my engine is not stock - ported head, higher comp pistons, headers, exhaust, lighter flywheel & RX7 AFM all add to the value of the cams. I'm slowly working on some IRTBs as well.

BUT

I am still running the stock ECU with all of these mods.....and the car idles like a charm at stock levels, revs out to redline nicely and makes more power across the range than it did before I took it apart.

I'm not sure how all this will translate to the BP engine, but since it is essentially the same design as the NA6
- you should expect a reasonably good idle with the ST4 cams, perhaps a little cammy.
- you should expect to lose a little torque in the lower range as the engine is otherwise stock.
- you should expect to gain power from around 4500rpm onwards.
- you should expect that you will hit the redline more often.
- you will realise that the ST4 cams are really intended to work best past your stock redline and that your inlet/exhaust are holding them back a lot.

For the money, I would recommend doing some other mods that change the input/output of the engine before you get into cams.

[Steampunk]

Hell, Alfa, Adam, thank! Yummy food for though I would be thrilled if I can get my car to get over 90kW@wheels.

Hellmun, you make a very good point regarding the powerband of stage 3-4 cams vs engine internals vs durability. It \"should\" be \"ok\" for me, and I say that with self-caution and your words of wisdom, but I will only do sprint track days 5-6 times a year, and I'm not one who guns it every time I drive it on the road.

Adam I will take it one step at a time so I can quantify the gains made by each major mod:
step 1 = EMS (probably MegaSquirt), and then I can delete the AFM
step 2 = cams, and maybe valve springs & shims
step 3 = better intake & ignition

Thanks for the advice fellas.

[Hellmun]

Bab's even has dyno graphs so you can see where a basic cam setup takes the power band on a similar car if you search for them.

(FYI Hellmun I bought Bab's car )

Hehe, FYI Alfa I bought the Diff from your car I think. I got my 4.1:1 crown wheel and pinion off Babs.

1red5 I hit the track once or twice a month. So reliability is way up my list and my car does get...very mountain dríven

It sounds like your in a position you could experiment, if my car is off the road I could miss Supersprint/Club days and I really dont' want that. I love hitting Wakefield with the NSW club. Let us know how you go. An ECU by itself is a nice power increase though if my NB8B was anything to go by. I believe I got 91kw ATW with Exhaust, ECU and a pod filter directly off my TB(with a bent PVC elbow). I also have a very black bumper so I think I'm running a bit rich too. Next time I get it tuned I'll get a shoot-out run.

[pcmx5]

Ired,

I am running Tighe 805c (252 duration,I think).

My dyno is in the Dyno section on this site.

Car is perfectly drivable, very slightly lumpy on idle and great mid range but the real push in the back is at around 5800 and mine just flies to 8000.

I have changed to a 3.9 and 6 speed so I can be in the range more often but with standard gearing any cam that produces less in the midrange would be a bit of a pain and you would need to be on a track to get any benefit much other than in first and second

My speedo is now accurate and my speed in gears are approx 50,90,122, 163 and god knows,god knows!!

It would be great if you could drive a couple of cars set up differently before spending heaps.

Peter

[Steampunk]

Yeah I saw your write-up in the dyno section Peter, and it was what made me want to go the same direction.
The only car I've been in with upgraded cams (6-speed, torsen, etc) is zoom-zoom's and it goes hard. Novice1 has decent cams in his, so I'll shoot him a PM, and hopefully arrange a meeting.

I rang Tighe cams (plus every other Aussie manufacturer I know), years ago and they seem to fob me off a little and just said \"that'll be a $1000 bucks\", without really asking what my engine is like, how I drove etc.
As you know, Tighe is Brisbane based and I am all for supporting the local guys, but I can source really good cams from the states for $550USD.

[CT]

Tighe 877C solids - 123rwkw - 12mm lift...extensive head mods. Idled at 1300rpm.

[green_comet]

Looks like your ordering from Integral Cams... Im getting a set of their stage 2's in a few months time, should be fun.

[hamish71]

Word of Caution.....

I am seriously looking at cams for my NB8B (01). I have my head competition ported, my intake extrude hones, and a 2.5mm overbore for the throttle body, as well as a tuned exhaust, and CAI.

My word of caution is that somewhere on the last couple of months, I think on the \"big forum\", Integral got a caning for the quality metal they use. I cant verify this, prove it, whatever, but, do some research. If my memory serves me right, it was Honda guys in the US who were having trouble with them.

[kula]

the red Garage Vary NB runs 304degree cams from memory.