thats why there are diagrams and multi meters and etc. theres nothing scary about it. people dont want to use their heads.

so if my swap has VTCs... would i get more with Z manifold or should i be looking into stock manifold mods?

From what i'm getting at in this thread, only if you can get teh Z33 VTC maps??

Not necesarily, no one with VTC has actually used the Z IM in place of their IM on the 5.5 gen engine. So it may or may not work as well. I'm going to guess that the Z33 VTC would probably produce more than the A33B but probably not a substancial difference. But then we wouldn't know until someone tried it.

^^^ yeah someone has i think vsamoylov has iirc

Vsamoylov has VTC's and a ZIM.

Guys I see what everyone is saying. Hacim105 is saying that know one with a 5th gen with a 3.5 has tried the manifold. Nismo3112 is saying that Vsamoylov has it and basically it is like a 5.5 since he is using the full 3.5 with 3.5 ECU. SO technically, someone with a 5.5 has the Z IM.

the 5.5gen ECU will not support the VTCs like the Z33 ECU. The Z33 has the capability to control both intake/exhaust timing whereas the A33.5 only has the ability to control the intake side. Also, IIRC, the Z33 has a greater range of variability (can vary the timing over a greater range) than the A33.5. If wiring isnt a problem the best thing to do would be to get a Z33 or a standalone (with the maps copied over) and skip the hassle of dealing with NATS/NVIS.

the 5.5 gen ecu will support the maps from the z33. technosquare can do that. the z33 got exhaust timing on the 35th anniversary model and the 2006 and up 350z. the earlier models didnt have vtc on exhaust.

i am going to be sending my spare ecu and have it reflashed by technosqaure for z33 maps for the vtc.

Now we are talking~!!!!

Hopefully, we can get a dyno once you do?

He(vsamoy) needs headers in order to really take advantage.......But I have a 4AT z33 reflashed VQ35... this weekend she will see the humblemaker.

Did you ever do a dyno before and after the install of the ZIM? If not than we still have no idea whether or not it is an improvement or not, which still leaves us in the same boat.

there was no "before" dyno, (i guess i should get mine dynoed to have a baseline) but... nearly stock 5.5 setup (Z manifold + exhaust) putting down like 230+ whp and 250 torque... not bad?

I don't see why people are so intimidated by trying to get the 2002+ Maxima ECU/harness to work in the older Maxima. Having wired up several Sentra's, I don't really find it all that difficult. CVTC makes such a huge difference... I accidentally cut the power wire, feeding the solenoids on the swap before last... The car lost a TON of low end/midrange! It would barely spin the tires.. Hooked it back up, and I couldn't believe how big a difference it made.

Travis

For those who did not catch this in the DYNO forum. SR20DEN's dyno with and without functioning VTCs. Ignore the absolute magnitude of the numbers as this was performed on a load based dyno.
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Top end is the same. People thought VTC's would make the 350z IM shine at the top end, no?

Maybe yes, maybe no. It all depends on the cam angle vs rpm mapping

5.5gen ecu stops pulsing the vtc solenoids at 6K.

I wish i had never seen that.

Crap, I didn't think the VTCs would make that big of a difference in the mid range. They make a bigger difference in the mid range torque than in the low range torque.

I'd assume SR20DENs low/mid range is going to be somewhat different then a stock IM VQ35.

If someone with a stock IM VQ35 gets a chance on a dyno, it would be nice to see if there is as much of a difference.

That dyno is very consistent with my dyno with no VTC's, low-mid range power is killed until 4000 rpm.

That's true for some VQ35s w/cams...

Isn't this in a way beneficial since I hear that a VQ35 in a 4th gen usually has traction problems??? Not for the mid range but for the low range. I am about to put cams in and have been thinking if it would be worth it to sell the ones I have and get Nismo. I hear those actually give you gains from the mid range and up and doesn't make the low end suffer as much.

Overall, now I am thinking if I should just get the parts to keep the VTC's. This is all so interesting.

NOTE: For discussion sake's only, let's assume that SR20DET's is using a Z33 manifold.

To put things in perspective, I am comparing SR20DET's dyno (no VTC) and my Z33 with MD spacer dyno. I've normalized his torque curve with mine at 4500 rpm.

From the graph you can tell that my hp curve peaks at 5600 and proceeds to falls flat on its face after that. On the other hand, SR20DET's peaks at about 6250 rpm and has a lethargic power drop.

Something is hindering my performance on the high end. What could it be?
- JWT ECU gives me timing that is at the very least at par with stock Z33.
- Fuel is good, evident by my A/F ratio (See Post 1).
- NGK iridium stock heat range plugs are about 10 month old (since swap)
- No codes code present.

Headers can't give me 37 whp at 6750 can they?

I am puzzled!

Or my comparions is plain and simply not an apples or apples, which it probably isn't.

meximax: Do you have a y-pipe?

don't you mean SR20DEN?

I just thought about something. According to the FSM, there are only 2* of valve overlap with the VTC's disabled. 3.5 swapped 4th gens using 3.0 ECU's have more overlap than this. Maybe the difference isn't as huge as this comparison would suggest.

Which brings up another point...you said earlier that the VTC's aren't pulsed after 6000 RPM. Since the curves look basically the same after ~6000 RPM, would that mean that the 3.5 ECU only dials in 2* of valve overlap approaching redline? Perhaps there are some extra horses could be extracted up top if the cam timing could be advanced some more.

The next time I get to use the dyno (Mustang) I might try to do it with a custom VTC map. One full advance and another in the locked postion (full retard). Everyone needs to understand that our Mustang dyno reads about 25hp lower than a Dynojet, at least on my specific car. So you can't do an honest comparison by overlaying my MD (load cell based) results to someone elses DJ (intertia based) results. Also, you have to take the indicated RPM on my MD graphs with a grain of salt. We don't have a tach pickup like they use on a DJ. The RPM has to be calibrated manually. And the test parameters are pre set before the run in MPH, so the software automatically ends the test based on the selected speed, and if I don't have the speed set high enough the test won't go all the way to my rev limit.

And as Icey pointed out, my car is probably the worst test candidate for showing the VTC differences. Someone else needs to emulate this on a near stock vehicle. I am suprised it hasn't been done and displayed already.

This makes complete sense to me. I was always under the impression that the CVTC is what allowed the 5.5 gens use the more aggressive cams. So they still get the peak hp but at the same time aren't losing so much power down in the low and mid range. I'm only going to guess and say that the reason the new 350Z is able to make more peak is because of the CVTC on the exhaust cams. Maybe they are able to have more aggressive cams because of the CVTC on the exhaust the cams.

I mean isn't that the reason why the 4th gens can only use fairly aggressive cams because at a certain point there is crappy idling?

This is pure speculation so if I'm wrong there is no need to bash me.

The 300hp Z33 engines have different intake manifolds and more aggressive cams than the 287hp Z33.

Yes, I do have a Y-pipe.



SR20DEN, I do understand that your dyno and mine may not be suitable for comparison, but aside from you, I could not find anyone else who has experimented with VTC and posted dyno's results.