posted on October 04, 2016 14:01
Project 350Z - Testing Jim Wolf Technology C2 Camshafts
So far we have tried some easy bolt ons like a manifold spacer, headers, high flow cats and exhaust on our 350Z all with good results. Naturally at this point it is time to change camshafts to get more bolt on power out of our VQ35DE engine. One thing that discourages many people from going this route is that changing cams on a VQ engine is quite a big job. Having two banks of cylinders and 4 cams is a lot of the reason. It's not super hard technically but it requires at least a couple days of wrenching and some care has to be taken to avoid problems.
Time consuming or not, camshafts are the next logical progression in the evolution of Project 350Z so we asked our friends at Jim Wolf Technology or JWT to provide us with some of their excellent C2 cams. We chose the C2 because they were probably the biggest practical camshafts that would work in the stock bottom end engine.
The VQ35DE is hamstrung with a stock 6500 rpm limit. With the stock bottom end the revs should not be raised past 7000 rpm due to weak rod bolts. Switching to later model rev up rod bolts will allow 7500 rpm but to go higher requires aftermarket rods.
The JWT C2 cams have 261 degrees of duration and 0.456" of lift and require JWT valve springs. We like JWT's cams because they use superior engineering to produce a cam with fast ramps and attenuation of spring surge by design. The cam lobe profile and spring harmonics are designed around each other to avoid surge and allow the maximum area under the lift curve. For this reason do not try to use other brands of springs with JWT cams. With a fairly short duration and a lot of area under the curve, the JWT cams have a fairly broad powerband.
To get the most out of the cams, we will probably need to do some ECU tuning at a later date but for now we will just bolt the cams in and test them to share the results with you.
JWT's C2 cams are ground on new billets right at their San Diego facility. JWT has a precision Berco grinding machine. Thanks to their mastery the grinding process, JWT cams have exceptional accuracy and a very fine surface finish, perhaps the smoothest we have ever seen. By using only new billets, the JWT cams are much easier to set up as the base circle diameter is very close to OEM.
JWT also makes this very simple, low cost and ingenious spring compressor for the VQ engine. It bolts to the head and uses these thumbscrews to push down a lifter bucket that has a hole drilled in it so you can remove the valve spring retainer keepers with a magnet through the hole. JWT only supplies one drilled lifter but we made 3 more so we could do 4 valves at once. Super cool!
JWT valve springs are made of a very high grade Kobe Clean Steel which is a chrome silicon vanadium vacuum arc remelted and vacuum degassed alloy. This process greatly reduces impurities and inclusions which are stress risers that can greatly reduce fatigue strength. JWT springs are also designed to avoid surge through avoiding excitement in 5th and 6th order harmonics by careful control of their natural frequency. JWT cams and springs need to be matched with each other.
So we disassembled the engine of the car to the point where we could install the cams. We had to remove the intake manifold, valve covers, front end accessories and the timing chain cover, timing chain, cam gears and oil pan. This is a good amount of work and we have just begun.
Monday, March 03, 2014 12:25 PM
Wow, that motor looks like a major PITA to take apart. I can't imagine the frustration involved with putting that front cover back on...
Tuesday, March 04, 2014 2:58 AM
No run in on the cams or a run and dump of a mineral oil??
Tuesday, March 04, 2014 8:11 AM
Cams were run in at 3000 rpm for 20 minutes. No need to run mineral oil, that's actually worse for running in cams. They are not rings.
Tuesday, March 11, 2014 6:01 AM
Pretty much any V engine with DOHC and variable cam timing is going to be a major PITA to disassemble. The valvetrain and timing chains on that VQ actually remind me of the ones on the Coyote 5.0, I would never, ever, ever take the Coyote 5.0 apart without help, at least not the first time.
Tuesday, March 11, 2014 7:26 AM
That does look like a lot of work. But if MotoIQ says it's worth it, I'm down. Might look at some cams this summer.
"If you think you may have messed up, pull it out and start over."— Good advice for any situation ;-)
Tuesday, March 11, 2014 5:08 PM
I'm curious if the nose will be able to detect a difference too? I'm guessing they have a smooth, stealthy idle. Any more bolt-ons before you get it tuned?
Tuesday, March 11, 2014 10:26 PM
Supercharged111: Their are a few more bolt-ons coming still. You should see those articles before too long.
Friday, March 14, 2014 4:48 AM
is there anything Howard can't or won't do?
Wednesday, October 05, 2016 1:25 PM
Can you adjust the intake variable cam timing on these with the UpRev? I would think that you could use that to get some of the low end power back.
Wednesday, October 05, 2016 2:35 PM
Wednesday, October 05, 2016 3:23 PM
Yes you can adjust the cam timing with rev up
Friday, October 07, 2016 1:12 PM
These very similar gains to when I tested Sunbelt cams on an E36 M3 3.2-liter, where'd I'd gained 13whp peak vs peak (245 vs 258 whp), and peak gain at redline was 18whp (which was nice). But I also had lost a bit more down low (over 20 lb-ft). That latter might freak people out, and shy them away from cams, but this stuff is way worth it when you see how much faster your speedo climbs at the top each gear! You're only going to notice the low-end torque loss when trying to pass someone on the highway in top gear at like 65mph or below.
Saturday, October 08, 2016 2:43 PM
seams like a lot of money (cam+install) for only 13whp...
Monday, October 10, 2016 8:50 AM
Yeah it is--but I'm not surprised. So many of us think we're going to get 30whp with a streetable cam in a small-to-medium sized motor, when it's usually not true. The marginal return in these normally-aspirated engines after basic upgrades usually is small after a full exhaust, intake, and tune. At least that's what I've seen. When comparing peak vs peak (as opposed to peak gains), the Schrick cams I tested in 95 M3, 99 M3, and Mini Cooper S made 9whp, 8whp, and 5whp, respectively. And the Sunbelts in another 97 M3 did 13 whp (but 18 peak).
In the land of so many boosted cars around us now, gains like this do sound so small. However, you do notice it and the car is still much more fun to drive (at least to me) because the characteristic changes slightly as well (unlike turning the boost up by 1 PSI to gain that 10-15whp). But yeah, it's still expensive, no doubt.
Here's that Sunbelt cam M3 I'd done:
From 5500-7000 RPM the car was totally different. I had a blast in it, and the current owner (who also owns a Viper) absolutely loves driving it to this day).
Monday, October 10, 2016 12:45 PM
I think the VQ is more to blame than "mild cam"... your USDM E36 M3 example also has a pretty lack luster engine. Unless you plan on doing a crazy race build, the VQ just isn't a good engine for NA power. And really only Sasha Anis is the only one to ever get anything really worth mentioning with the VQ in NA form.
There are plenty of engines that get 20-30whp from streetable cam upgrades. K20's and LSx's come to mind, MZR is another...
Monday, October 10, 2016 12:53 PM
A lot of gains depends on how mild the stock cam was and what sort of variable cam timing it has if it does.
Monday, October 10, 2016 1:46 PM
It's not like the VQ is a gem of an engine in stock form either... it's power/liter is equivalent to most minivans, maybe worse in some cases
Monday, October 10, 2016 5:31 PM
Man if there was ever a case for going turbo.....