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Track Whore
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Discussion Starter #1
I superimposed the dyno charts of a 93 full bolt-on SE-R with stock cams and my full bolt-on 98 SE-R with C3 cams. The results are pretty interesting. It shows clearly that the C3 cams are racing cams. Take a look.

http://www.geocities.com/ndahi12/naji_93ser.htm

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Naji Dahi, aka Red Mist
Fast 1998 SE-R Last of the SE-Rs
163 hp, 124 lb-ft torque
Slow 1996 G20 (AGXs/G20t springs, K&N drop in filter)
 

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70/30 Racing
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wow! look at that top end HP and TQ advantage that the C3s have over the stockers! hmmm....the powerband doesnt look too bad for drag racing though, just launch a little higher, above the dead spot in the torque curve. wanna race? ;-p

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Steve Rockwood
98 SE-R w/stuff
 

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Track Whore
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Discussion Starter #3
<font face="Verdana, Arial" size="2">Originally posted by HotshtSR20:
wow! look at that top end HP and TQ advantage that the C3s have over the stockers! hmmm....the powerband doesnt look too bad for drag racing though, just launch a little higher, above the dead spot in the torque curve. wanna race? ;-p

</font>
The advantage at the top end is huge; 40hp and 27 lb-ft of torque. I wonder what my dyno chart would look like vs a Type R dyno chart. I will do that next. If your going to the SERCA track event, then we can play




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Naji Dahi, aka Red Mist
Fast 1998 SE-R Last of the SE-Rs
163 hp, 124 lb-ft torque
Slow 1996 G20 (AGXs/G20t springs, K&N drop in filter)
 

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GUPAMF 4 Life
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Hey Naji, could you and your brother check again to see if you can find those tools? I'm stressin! Thanks man. I will be advancing my exhaust cam soon. Compression test came out semi decent. Not enough to justify a 20 hp loss.

Terrin
92 SE-R
 

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I read in se-r.net a long time ago that cam gears were used mainly to MOVE the powerband around. In theory, could you not tune these cams to start making power sooner, even if it meant tapering off a little at redline? Essentially moving the power peak to a lower rpm?

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92 NX2000
Intake/Headers/Exhaust/Cams/Flywheel/Street Tires
14.545 @ 95.57 mph

 

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<font face="Verdana, Arial" size="2">Originally posted by Son Of Skyline:
I read in se-r.net a long time ago that cam gears were used mainly to MOVE the powerband around. In theory, could you not tune these cams to start making power sooner, even if it meant tapering off a little at redline? Essentially moving the power peak to a lower rpm?
</font>
That is correct for the JWT S-series cams... Though, how do you think, Rob, Naji, and eventually Terrin got more power out of the C3 cams? Tuning via cam timing adjustments.

--Andrew Phan
Leaving for Willow Springs in about 4 hours
 

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A couple of comments on the recently published C-cam test results from SCC.

As I was driving home from dyno'ing that night, I noticed some weird drivability problems/hesitation that I hadn't noticed before. I figured that with all the ECU swapping that was going on, I didn't ground the ECU chassis correctly (it actually wasn't even bolted in--just sitting on the floor), and that was causing the weirdness.

Anyway, I drove the car home and parked it, and didn't look at it again for some time (the car is actually rarely driven on the street any more). A couple weeks later, I fixed the ECU, but the problems persisted. WTF??? Upon closer inspection, I found a rather large crack in my header (gen2 Hotshot--predates new anti-cracking changes). Well, two days ago, I finally replaced the primary. GEEZ!!! That was causing all kinds of drivability problems! I think that a lot of the low-end losses shown in the testing were actually a result of the header crack.

I have summarized my own dyno testing and the results will appear in the next SERCA newsletter.

With the proper header, my gains with the C3 cams were 33 peak horsepower (going from 135 to 168 whp). Maximum horepower gain was about 45 whp at 7500 RPM. The C3's lost torque relative to the stock cams below 3600 RPM. They are even with the stock cams from 3600-4300 RPM, then they take off from there.

These cams really rock, but be warned: they are really a race cam. They may require some custom dyno tuning to work on your car (the car's performance becomes very sensitive with cams these wild), and they are tough to live with day to day.

For Street cars, I highly recommend the C2 cams. The C2 cams looked much worse than they really are in the SCC tests, because they were tested last (when the header crack was the biggest--I can see daylight through it!). In my testing, C2 cams only lost about 5 ft-lbs of torque relative to the stock cams at 2500 RPM. I still made 158 whp with the C2 cams. The C2 cams can be lugged in bumper to bumper traffic 5th gear at 1200 RPM, something you can't do with the C3's. I highly recommend these for powerful street cars.

You guys who are SERCA members will get the full low-down (including dyno plots), in the upcomming issue!

Rob
 

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Guanaco Tuner
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Well the hp curves are pretty similar (shapewise anyways) until 6k. Looks good Naji.. Maybe you should superimpose it over my dyno?
Hope you work your cams out Terrin!
 

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as far as the c3's being race cams, what kind of problems do they present for every day driving? shaky idle? poor low rpm performance? what else
 

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<font face="Verdana, Arial" size="2">Originally posted by KikoSanchez182:
as far as the c3's being race cams, what kind of problems do they present for every day driving? shaky idle? poor low rpm performance? what else</font>
Questionable smog status (not sure you'd pass a road side smog test--I passed with C2's), reduced fuel economy, rough idle, surging/bucking at low engine speeds (like sub 1500 RPM). The torque loss isn't that big of a deal, really; the torque loss is really only bad below 2700 or so RPM; not a place I usually operate.

Don't get me wrong: I'm not saying the C3's aren't streetable; they certainly are. I mean, if you race a lot, but still want to be able to drive your car to work once and a while, to the track, etc, then they're OK. However, SOTP, the C3's don't really *feel* much more powerful than C2, even though there's a 10 hp difference. C2's drive really nicely; I just think that they are a better all-around cam, at least if on-track performance is not your top priority. My car is not longer my daily driver, although it is still driven on the street. I like the C3's, as long as I'm not in stop-and-go LA freeway traffic. If my SE-R was my only car, I'd sacrifice 10 hp and run the C2's. Since I don't drive it every day, I like the C3's.

Rob
 

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<font face="Verdana, Arial" size="2">ClassicSE-R wrote:
If my SE-R was my only car, I'd sacrifice 10 hp and run the C2's.</font>
Rob, unless I'm mistaken the C2's also do not require upgraded valve springs/retainers like the C3/4s do, right?


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'91 Classic w/the usual stuff

"It is better to go into a corner slow and come out fast than to go
into a corner fast and come out dead" - Stirling Moss
 

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Track Whore
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Discussion Starter #12
<font face="Verdana, Arial" size="2">Originally posted by grailer:
Rob, unless I'm mistaken the C2's also do not require upgraded valve springs/retainers like the C3/4s do, right?
</font>
ALL C-series cams require the springs and retianers. And there aren't C4s, otherwise I would have bought them


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Naji Dahi, aka Red Mist
Fast 1998 SE-R Last of the SE-Rs
163 hp, 124 lb-ft torque
Slow 1996 G20 (AGXs/G20t springs, K&N drop in filter)

[This message has been edited by nj1266 (edited 10-11-2001).]
 

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Track Whore
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Discussion Starter #13
<font face="Verdana, Arial" size="2">Originally posted by 92SE-R:
Hey Naji, could you and your brother check again to see if you can find those tools? I'm stressin! Thanks man. I will be advancing my exhaust cam soon. Compression test came out semi decent. Not enough to justify a 20 hp loss.

Terrin
92 SE-R
</font>

I looked all over my trunk. But did not find any additional tools. I hope that you can find them.


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Naji Dahi, aka Red Mist
Fast 1998 SE-R Last of the SE-Rs
163 hp, 124 lb-ft torque
Slow 1996 G20 (AGXs/G20t springs, K&N drop in filter)
 

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Track Whore
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Discussion Starter #14
<font face="Verdana, Arial" size="2">Originally posted by Son Of Skyline:
I read in se-r.net a long time ago that cam gears were used mainly to MOVE the powerband around. In theory, could you not tune these cams to start making power sooner, even if it meant tapering off a little at redline? Essentially moving the power peak to a lower rpm?

</font>
You can tune the C3s to give you more mid range, but you will sacrifice some top end. To get more mid range you need to advance the intake cam by 2 degrees.

Advancing the exhaust cam and keeping the intake at 0 gave me more top end. And that is the chart that you see.

Now I am running with a 2 degree advance on both the intake and exhaust cams. But I do not have a dyno chart for that one.



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Naji Dahi, aka Red Mist
Fast 1998 SE-R Last of the SE-Rs
163 hp, 124 lb-ft torque
Slow 1996 G20 (AGXs/G20t springs, K&N drop in filter)
 

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GUPAMF 4 Life
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1,240 Posts
Hey Naji, thanks for checking. Also, with both cams advanced, I noticed some high end loss. It was definitely noticeable. On the other hand, mid and low range seemed much improved. At 3K rpm's in first gear I could punch it and chirp a little. That's a big contrast from when the intake cam was straight up. It would just get all loud and sound boggy.

As far as streetability goes, I daily drive this car. It is my only car. I go to work and school about 30-40 miles roundtrip everyday in rush hour traffic. It is not bad at all. When cold, it likes to idle really low and shaky, but once its warmed up, the idle is rock solid. With the ECU, the idle feels like stock with motor mounts. Without the ECU it loped hard and you could feel it, but still, it wasn't bad. I drove around almost 2 months without the ECU. The car has never stalled while idling at a stoplight so its not like you have to worry about it. As far as the bucking goes, with the ECU it's greatly diminished. You just have to know how to drive it. With the stock ECU however, it was VIOLENT and it would happen at random times below 3K rpms. The bucking was worse than when you were first learning how to drive stick. Tires chirping, tach needle bouncing all over the place, old ladies giving you hard looks. With the ECU, its much more liveable. But, as alwasy, YMMV. I consider myself fairly tolerant of my car. Most people probably are not. Whenever I drive my gf's 2000 Sentra SE, I cannot stress how much better it is to drive her car. It is so smooth and so refined. I love that car.

Regarding my low power, it really seems to me as if the cams do not have the 2.5 degrees advanced on the exhaust cam. I think JWT sends out billet cams to be ground to their specs right? Could this company possibly have not ground in that advance? It just seems that way because everyone I've talked to with the C3 cams seems to have to advance the exhaust cam in order to make good power. Hey Rob, do you have the dyno sheets handy where you put the C3 cams straight up? I remember you lost 10 hp and 5 tq from the C2 cams initially and you got some of it back by advancing the ignition timing. I'm wondering if my power curve looks like yours did without the exhaust cam advanced. Give me a call.


Terrin
92 SE-R
 

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Guanaco Tuner
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Ok... damn you Rob!! Ok I'm sold.. I'm gonna get the C2's. Anyone know if they like NOS at all?


Luis - Still too scared to flick the switch for the first time on his jwt 50shot kit.

93 Classic - 238k+
152.3hp 135.3tq
 
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