krismax

iTrader: (15)

We will find out , I will have the manifold on and dyno tested within the next 30 days.

JeffesonM

iTrader: (5)

I too would like some more details on swapping the 2k engine into the 96 car. I was under the impression that 99-2k1 have a different ECU harness than the 95-98 models.

vsamoylov

next project that i plan to do is put a 6 speed into my max. i want to know how it will be cause i am a 2k auto right now

JSutter

iTrader: (46)

Have any of you guys heard of the SR20DE. Yeah the one in the SE-R and G20. Well in over the years Nissan changed the cams slightly for emmissions. The early (91-93) high port SR20, intake cam had 10 degress more duration and a bit more lift then the 95-99. Just swapping out the smaller and newer intake cam with bigger and older cam gave 4-6 hp. Maybe the same applies to the VQ30DE..... hey its worth a shot.

And for all of you thinking vsamoy is nutts just look at his web page. there is a 2000 VQ in his 96, using the 96 intake manifold.

http://www.cardomain.com/id/vasiliy

krismax

iTrader: (15)

It sounds like your saying the older cam gave more power? And if the cams are worth that little difference than the manifold has to be worth alot.

stephenlc

iTrader: (1)

Where can you get regrinds? Crane? Anybody know a good place to get regrinds, and what would be a good duration and lift for a boosted car?

nismology

iTrader: (8)

What exactly are you saying?? That somebody should take a VE30DE intake cam and swap it into the VQ??

The point is, the DE has more duration on both cams and more overlap than the DE-K. The intake cams are identical.

Eric425

I sort of feel sorry for you. Somebody comes up to call you BS on your swap every few months, it seems. I've only been on since october or november or something like that and this has already come up twice. I think it's because theres something in the FAQ that says it can't be done.

Dave B

If these DE-K cams are so great, then why does the DE-K motor make the same power from 2000 to 4500rpms as the 4th gen and LESS power from 4500-5500rpms? Not until 5500rpms does the DE-K power advantage come into play and that's only because of the variable intake manifold. It looks to me like the exhaust cams were changed for mostly emissions. To me, swapping out the cams would be a big mistake. Check out Steve's dyno comparison if you don't believe me.


Dave

nismology

iTrader: (8)

Well it depends on which graph you look at. The graph with just WHP shows the 5th gen making more HP from 2500 RPM to redline. Clearly it's a more flexible engine at all rev-ranges. It's only when weight is included that the 4th gen has the edge.

But I do agree with you that most of the added power and flexibility comes from the intake manifold. The DE-K cams would be useless to 4th gens.

Dave B

You're right. I mistakingly read the HP/weight comparison. My bad. The DE-K does seem to make better power from 2500rpms on with increases of 5fwhp to 10fwhp in most places along the graph. I still think most of the advantage comes from the intake manifold though.

It would be great to see a dyno of DE-K block with the MEVI/JWT ECU. It may be a cheap option for some increased power. I'd rather swap the block than try and mess with the cams.


Dave

BSwithTF

iTrader: (8)

I agree. Id reather just strip the engine down to block and heads and put the intake system on from mine. I'm not to sure about swapping the cams myself but I don't think I'd have a problem doing it this way. Supposedly there's a lot that was changed with the DE-k so this way we could take advantage of all the other little changes.

nismology

iTrader: (8)

As in one of my previous posts, the DE has more duration for both the intake and exhaust valves and has more overlap than the DE-K valves. The only real advantage the DE-K has is the intake manifold. The internal dimensions are the same. I think someone that tries to make a hybrid DE-K head/block with MEVI will be sorely disappointed. We will not match the DE-K's performance until someone swaps it's VIAS onto a DE.

If you reaaaaly want extra power that bad, might I suggest going with a custom intake manifold.

BSwithTF

iTrader: (8)

So do you think a DE with a VIAS will be more potent than a complete DE-k? I'm all for more power with less work!

JSutter

iTrader: (46)

Where did you get VE from? What I was saying is someone should try putting the VQ30DE-K cams into a VQ30DE.



And yes the older SR20DE intake came gave a hp increase when swapped into the newer SR20DE.

nismology

iTrader: (8)

Oh ok gotcha. At least from the data that was posted earlier in this thread, our cams are just fine.

And I knew about the early SE-R cam mod. I used to visit sr20deforum.com all the time.

As potent, if not more. If someone managed to get the 5th gen VIAS to work on the DE, got the JWT cams and ECU, full exhaust, lightened flywheel and UDP, I dont see why a 4th gen 5-speed couldn't be able to run low low 13's on slicks.

krismax

iTrader: (15)

That sounds like a map to 12's to me

BSwithTF

iTrader: (8)

You hope so.

We're all anxiously awaiting you to get that VIAS working. Hopefully people will still want a "old school" VI after this is figured out. I'm gonna need to sell mine.

SteVTEC

In other words, they're not the same.

VQ30DE
Intake Valve Open: 3 BTDC
Intake Valve Close: 49 ABDC
Intake Valve Duration: 232
Valve Lift: Nominal
===
Exhaust Valve Open: 49 BBDC
Exhaust Valve Close: 3 ATDC
Exhaust Valve Duration: 232
Valve Lift: Nominal

VQ30DE-K
Intake Valve Open: 3 BTDC
Intake Valve Close: 41 ABDC
Intake Valve Duration: 224
Valve Lift: Nominal
===
Exhaust Valve Open: 49 BBDC
Exhaust Valve Close: 3 ATDC
Exhaust Valve Duration: 232
Valve Lift: Nominal + 0.525mm


So there are differences on both cams. Compared to the VQ30DE, the DE-K has slightly less intake cam duration. Intake valve opening is the same, but it closes 8 degrees earlier on the DE-K. Lift however, is the same. On the exhaust side, timing and duration is identical, but the DE-K has an additional 0.5 mm of lift. This makes sense since the DE-K needs to evacuate a much higher volume of air at the top-end due to the VI.


I count 6 degrees on both engines.

Not sure how you came up with 104/96, but overlap is the difference between when the intake valve opens and the exhaust valve closes. More overlap is good during power-on in the low/medium speed range because there is a scavenging effect that helps to draw in the intake charge, but it can also cause a rough idle and crappy emissions idle also.

For a given lift/duration, earlier valve opening and closing will help to optimize low/medium range power. This is because if the intake valve is left open too long, some of the intake air charge can actually bounce back out of the intake port (lower revs) and then your Volumetric Efficiency (VE) decreases. As the revs increase, the optimal point for valve closing slowly shifts to later in the cycle, and this is what continuously variable valve timing systems (phase shifter systems, Toyota VVT-i, Nissan CVTC, etc) do.

For reference, maximum intake valve open advance is 27 BTDC in the 02-03 VQ35DE Maxima, which is 24 degrees sooner than a VQ30. Exhaust valve close on that engine is fixed at 4 ATDC, for a maximum overlap of 28 degrees (vs 6 degrees). That's good for power-on at lower revs, but it's not good at light throttle (such as idle) because the idle will be rougher, and fuel mileage lower, and emissions will also be much higher because a greater portion of your intake charge will leak out of the exhaust port. So at lower revs and light loads, overlap is reduced to the minimum. Since the VQ30's don't have VVT, they're forced to run very little overlap all the time which is good for idle, cruising/emissions, and eventually top-end power, but not really low-end or mid-range power. And this is the beauty of VVT systems. You can have your cake and eat it too.


So as for how this would effect powerbands, if I have all of my cam theory right it would be as follows. The longer duration and later intake valve closing on the DE intake valve would actually help top-end slightly. The DE has the very long fixed intake runners taking care of the low-end which its stuck with (non-variable) so the later valve opening sorta makes sense since Nissan still wants to have some top-end on the engine. In the DE-K, perhaps the lower duration is okay becuase they now have the VI. Earlier valve closing would help low-end slightly which is good (since it's a heavier car with still a 3.0), and then the VI takes care of top-end. The larger exhaust valve opening would help to evacuate the extra air volume at the top-end. The DE's 0.5mm lower lift might not be sufficient.

So it would be interesting to see a DE/MEVI with a DE-K exhaust cam transplant, and of course before and after dynos.



To MrGone.


THANK YOU

This was one of the great unsolved mysteries of the org and with a little digging through service manuals you have solved it. Major props to you.

Nismo87SE

Looking at the cam specs the VQ cams are pretty mild. The VE and VG's had cams with 248* duration. It appears that the VQ's specs are simular to the low port SR20DE cam specifications while these are 2 different engines, simular gains in power should be the results.

Given the fact the VQ is DOHC, it would be a waste of time to install OEM cams unless they where alot stronger. Right now JWT and Tomei have cams out and they should give a nice 8-20whp gain. I've seen simular cams installed in other VG30's and SR20's that make that much power. Personally I've installed isky 262 cams in my old max and JWT S3's in the se-r. In both cases midrange and topend power was greatly increased. For the maxima I had a protorque TC so I didn't notice any kind of torque loss downlow and the engine pulled to redline with no problem.

I'd imagine the best setup would be the DE-K IM, tomei or JWT cams + valvesprings/retainers, JWT ECU. This should produce a power band that pulls cleanily to the 7200rpm rev limiter. Power peak would be around 6200-6400rpm with torque peak around 4700-5000rpm.

SteVTEC

If you think the VQ cams are "mild" look at the specs for the Honda J30A1 engine in the 98-02 Accord V6.

Intake non-VTEC Primary: 179*, 7.5mm
Intake non-VTEC Secondary: 78*, 1.8mm
Intake VTEC Both: 225*, 10.0mm (above 3500rpm only)
Exhaust Always: 200*, 9.5mm

The VQ30DE cams are "stump pullers" compared to that. No overlap whatsoever either, and the intake valve never opens before 5* ATDC.


Does anybody know the actual lift specs of the VQ cams? The FSM just gives the total cam + lobe height, which is not the actual valve lift spec. I'd like to figure that out too.