nismology

iTrader: (8)

I don't feel like retyping it in different words so i'll just copy and paste the IM convo...lol


ReelDeel25 (8:04:09 PM): the DE-K relied on a dynamic supercharging-type VIAS for it's top end
ReelDeel25 (8:04:19 PM): since it didnt have VVT
ReelDeel25 (8:04:33 PM): the 3.5 doesnt have that type of IM
ReelDeel25 (8:04:39 PM): so it relies on cam timing for top-end
ReelDeel25 (8:04:51 PM): you have neither
ReelDeel25 (8:04:53 PM): as such
ReelDeel25 (8:04:57 PM): you need to compensate
ElReyNica2003 (8:05:45 PM): oooo
ReelDeel25 (8:05:11 PM): with retarded intake cam timing, to mimic what the 3.5 ECU would do at high RPM
ReelDeel25 (8:05:21 PM): now for teh numbahz
ReelDeel25 (8:05:46 PM): stock VQ30DE cam timing closes the intake valve at 49* ABDC
ReelDeel25 (8:06:28 PM): DE-K is sooner than that for better low end, but because of it's VI and higher exhaust cam lift it still has great top-end despite having less intake cam duration
ElReyNica2003 (8:07:46 PM): ok
ReelDeel25 (8:07:43 PM): stock 3.5 cam timing with the VTC disconnected (full retard...aka 6K+ RPM) closes teh intake valve @ 64*
ElReyNica2003 (8:08:45 PM): wow
ReelDeel25 (8:08:16 PM): the VTC cams sprocket has 40* of cam timing adjustment
ReelDeel25 (8:08:32 PM): they're drilling/making the adapters to be halfway
ReelDeel25 (8:08:35 PM): 20*
ReelDeel25 (8:08:36 PM): so
ReelDeel25 (8:08:51 PM): 64* minus 20* = 44 degrees
ReelDeel25 (8:09:11 PM): 44 (what you have) vs. 49 (what the VQ30DE has)
ReelDeel25 (8:09:12 PM): O_o


What does this mean to you? Retarded intake cam timing for better top-end power. Of course, doing this will move the curve to the right. You'll sacrifice some low-end but the 3.5 is so torquey that i'd part with that for improved top end. I've seen the dyno graphs of some current A32 ECU 3.5 swaps and have been less than impressed with the HP at high RPM. This is a cheap and easy way to increase top end power.


UPDATE:You guys aren't doing as bad as i previously thought. According to a member who was there to witness tilley drilling a set of 3.5 cams in person, tilley uses lobe separation angle to determine what the intake cam timing is going to be like. He drills the intake cams so the LSA is 113* just like on the stock 3.0 cams. Makes a ton more sense to do it that way.

Sorry for confusing you guys. I just just going by what a prominent member of this forum told me. Now we know for sure, finally.

95BLKMAX

iTrader: (10)

Indeed, you sure learned that fool ElReyNica. What a n00b, he did his engine swap not thinkin of this FTl for him, bahhah.


Hey wait a second, thats ME!!!

gtr_rider

iTrader: (50)

.... ok ....

nismology

iTrader: (8)

THREAD FAILURE....i had a feeling...

scrhale

Oh no I understand it fully. What you do is you get your @$$ off your computer, do some research, purchase the A33B ECU, stop changing timing equipment, and get that *&^$ing VTC working!

Actually I think Nismo is suggesting that we get our intake cam adapters made in a more retarded state so we get more high-end. We will lose low-end, but the fact that the 3.5 is so strong on the low-end will compensate for its loss. Using cam adapters that are more retarded on a 3.5 will still have a lot more low end than our stock 3.0 engines.

95BLKMAX

iTrader: (10)

Something that I mentioned to Nismology was that I would be willing to tear into my timing equipment one more time to change the intake cam adapters for a more timing-retarded pair, ONLY if I see the power gains to be worth the effort.

Doing that is not as easy as say an intake, we're talkin about a full day's worth of work to change those adapters in front of your house with hand tools. I KNOW that it will yield more power on the top end, that is a given. However, what would that gain be (obviously depending on the amount of retard)? If that gain is worth all the labor (to me, after all the sense of "worthism" is relative) I'd do it. Perhaps one day, the folks that have access to doing this (cough*stephenmax or tilleys*cough) can make a set and do a before and after dyno comparison, or 1/4 mile passes (trap speed).

Doing this intake cam retard, in addition to SSIM, would yield for some serious top end power without having to use aftermarket components.

For us that have already done the swap, some would do it right away, some would be skeptical to know the results. But for the ones that are about to do the swap, or plan to do the swap, doing this is A MUST. Might as well do it now that the engine is out, than going back and doing it with the engine in the car like me.

krismax

iTrader: (15)

If your gonna go with aftermarket cams. would you still do this?

And if your installed a peaky cam and did this would your low end be awful?

speed racer

iTrader: (10)

That's what I been wondering. If people are doing the 3.5 swaps why not switch to some aftermarket cams. I can see why people who have a 3.0 would use the 3.5 cams but honestly if your swapping you might as well go big.

nismology

iTrader: (8)

This assumes you have stock cams. With aftermarket cams i'd still tinker with the cam timing to dial my desired powerband in, for sure.

nismology

iTrader: (8)

Why's that? Aftermarket cams are 600 bux at the very cheapest. It's not a MUST DO thing initially especially since most people are on a budget..

MaxBlack97

iTrader: (11)

couldn't have said it better myself

NmexMAX

iTrader: (22)

Good thoughts on that nismology. Go at it mechanically.

Whereas for me, I'm thinking of a manual VTC 'control' box.

95BLKMAX

iTrader: (10)

most people are happy with the power out of just going from 3.0 to 3.5 alone. But yea man most of us are young, working part-time and or going to school. So spending an extra $699 for say debuloz cams, when you can get the whole 3.5 for that much, cams dont seem to be much of a priority being under a tight budget.

speed racer

iTrader: (10)

Budget is key to alot of the modding we do, but IMO I think if your going to be doing a swap like this, than you should spend the extra $$ for more aggressive cams. You have to open up the timing chain already and set the TDC to put the cams in. Why not pay a little more for increase in power.

But I agree that its not something to do initially especially when it comes to changing the internals of the engine. Usually set aside for the more experienced.

nismology

iTrader: (8)

Why should someone spend the extra money if they don't have it? The gains from the "stock" 3.5 are big out of the box and I disagree with you completely.
I wasn't referring to lack of experience, but lack of money.


Anyway, back on topic we go....

915Max

iTrader: (6)

it would be nice if someone would make adjustable cam gears rather than just a spacer/adapter that would only give us one option for retarding the timing... does that sound right!?... retarding the timing!?
Even at that... it would be a pain to be able to go in and adjust them to your desired position.... so I guess its not so good of an idea...

MaxObesset

iTrader: (25)

so whats the ideal motor swap

Alex_V

VQ35DETT

~Alex

nismology

iTrader: (8)

Keep the OT crap outta here please...that's as nicely as i can put it. Thanks.

krismax

iTrader: (15)

that nissan dealer that races the drag 350 z's . they use adjustable cam gears but it seems cheaper and easier to do it nismologys way.
I will be getting aftermarket cams in late 07 or early 08 and wonder if i should change the cam timing with them. Iam thinking the other way actually if my powerband is to peaky with the cams and i want to bring it down alittle ,i could advance alittle? but how would you know how much to go each way? this isnt easy like a honda to open up.

I have the JWT spacers with the drilled 3.5 cams .

GodFather

iTrader: (10)

Reading from the Convo, the math makes great sense to me. I really don't see much con's using the aftermarket cams which have higher lifts for more air, however, basing on the 20 degree retarding spacer math...I'd use a 3.0 aftermarket cam to do this. It seems to me that 3.5 aftermarket cams has too much duration that retarding 20 degrees probably isn't enough to shift the powerband to the right. If using 3.5 aftermarket cams, retarding on the spacer has to be way more than 20, which finds us very much away from the low end ballpark that VQ's are on...Is it becoming a Honda that way?

Sorry, I'm a semi-veteran in the all-motors, but I'm still a newb on these cams and timing talks. Do correct me if I'm heading into the wrong playgrounds.

Anyways, great info you got here, Nismology, alwasy good to hear stuff from your posts.

-Peter-

NiZMo1o1

iTrader: (45)

aye Nismo , Are you free soon to swap in that motor ?

nismology

iTrader: (8)

I can't believe i'm about to say this but a timing belt with no timing cover would be the ideal configuration for tuning purposes.

nismology

iTrader: (8)

What do you mean by ideal?

95BLKMAX

iTrader: (10)

I think he means to ask what would the best 3.5 swap on the Max be...

Well buddy only you can determine that, with what you'd use the car for (street/ track only), your driving style, how much you can afford. No one can honestly tell you what the best option is for you, that's up to you to figure out. But please leave that for another thread.

Back to topic...

Hmmmm, I wonder how much of a mission it would be to rig up a dry-timing belt setup such as that of the RBs and 2JZ motors. I think there is barely enough clearance in the compartment for the width of the gears to fit, but HOW to make them fit, and how to mount a tensioner for this. You'd have to also fabricate a cover for the belt so crap doesnt damage it.

Hmmm, actually now that I think about it, to fit belt timing gears on the cams we might have to canibalize the rear timing cover (the outer is a given its would have to go) to fit the gears if necessary.

hmmm, Also a plate could be made to block off the chain's tensioner. Problem is though where and how to mount the belt's tensioner (which of course would have to be spring loaded). Unless its easier to modify the guide in a way that it could be used in combo with the chain tensioner but with a small pulley instead of a guide (to eliminate that friction).

Anyways these are all ideas as to how this could be made to work. How feasable could this be?? Does anybody know if the V6 Accord motor uses a timing belt by any chance??

Interesting stuff! keep this going

(sorry that I may be taking the thread in another direction, but this might turn out good)

NmexMAX

iTrader: (22)

It uses a TB.

It's a good idea and all, but I think nismo's idea is better, IMO. Because as stated, the 3.5L is already torquey, especially when strapped to an A32 chassis.

95BLKMAX

iTrader: (10)

oh no dont get me wrong, I love the idea of more retarded timing for the intake cams. The reason Im pondering of a TB swap is because of the ability to have a fully adjustable cam timing capacity via adjustable timing belt gears. If there was a way to convert our timing system to belt, we COULD gain that capability and thus build on the idea of the intake cam retard AND THEN SOME. This would be a great option (if feasable) for example, for people that swap the 3.5 in and want to get the most out of it NA, but are looking into boosting it later. Just an idea in the air worth discussing

krismax

iTrader: (15)

must not have read my thread , performance nissan in new york has cam timing gears on there 3.5 350z and i believe they sell them as a package deal. i dont think they switched to belts

speed racer

iTrader: (10)

website please

JClaw

iTrader: (17)

Ok I am sold. If I retard BOTH intake and exhaust cams by 20 degrees or a little more, I dont need to fill the old holes in my nismo cams.

Can anybody throw out an educated guess as to what differences it would make going from 44 degrees to 64 degrees or so?

I think this is DEFINATELY the way to go with either a 240 or a lightened maxima (sub 2700 lbs like krismax). All top end, gradual powerband = good traction and your @ss firmly planted in the seat from 5000 to 7000. If you guys think this is too much in a maxima, increase the final drive ratio to 4.xx.

eng92

iTrader: (3)

All this talk is in crank angle degrees so the holes in your cams would only be moved by 10 degrees.

Thought I would mention it just in case you were having a momentary lapse of reason.

nismology

iTrader: (8)

^^ What he said.



Also, for us to come to some kind of a conclusion as to where the cam timing should be set we need to know EXACTLY where the cams were drilled to begin with.

Edit: When you say 20* (in reference to how far away the new hole needs to be drilled as to not interfere with the old one) do you mean in cam degrees? If so, retarding the cam 20* will result in a 40* crank angle change in cam timing. That's a huge change and might reduce the dynamic compression too much considering you will be running the OEM static compression ratio. Can you confirm that? Generally extreme intake cam durations are paired with raised static compression ratios to keep cylinder pressures up.

JClaw

iTrader: (17)

LOL! Im not having a momentary lapse of reason, all this timing stuff is new to me! But yeah now I remember that it has to be divided first.

Damn. Looks like 10 degrees is not enough to clear the old holes. Looks like Ill have to fill 'em out either way. Oh well. I have all winter.

JClaw

iTrader: (17)

No I meant 20 cam degrees. But now that I look at it, it might require 25 degrees of retard to clear the old holes.

Anyway. I always thought the cams in 3.5 swaps were drilled to mimic full retard (VTCs unplugged) so I didnt want to go too crazy with the retard. But since we run 44 degrees static with the cam adapters that I currently have, I might want to retard a bit more than a full 3.5 with VTCs after 6k. These nismo cams seem to peak around 6200 from the dynos Ive seen and Id want the peak to be around 6500-6700.

So if the 3.5 with VTCs sees 64 degrees at full retard, I might aim for something like 70 degrees static. Thats 26 crank degrees and thus I would want to retard both cams by 13 degrees. This will result in lower cylinder pressures, thus they become filled the same amount higher in the RPM range. It will also result in a better idle, crazy top end (5000+), and crappy midrange.

Do I have it all right?

And of course, I refuse to lose any overlap at all, so Id want to retard the exhaust cams at least as much as the intake cams, maybe a little more. What effect would slightly more overlap have on cylinder pressures assuming 13 degree retard on both intake cams already? Even less pressure?

Ill work on getting some non blurry pics of the cams. But its pretty obvious just by eye that the 2 intake cams were drilled wrong (different from one another, has to be at least 3-4 degrees off).

Nismo87SE

I was wondering if anyone has actually measured the change in power vs change in cam timing? The consensus is that retarding the intake cam is the way to go, however during actual tuning it might not. Now I've done a lot of tuning in my own car with adjustable cam gears. Unless I'm totally mistaken, basically what I found is that advancing intake cam relative to stock increases torque in low-midrange while making the idle rougher. Now retarding the intake cam reduces low-midrange torque but it does make a little more power up top and the idle is smoother.

For the exhaust cam in my case doesn't seem to make much of a difference in power given retard or advance. However, it will make the idle smoother by retarding the exhaust. Right now I'd pay good money if my engine (SR20DE) was able to be retrofitted with VTC control. If I could get like 9* of change, I could gain like 8-11wtq below 6000rpm and gain like 10-12whp over 6000rpm if able to retard intake cam as well. With aftermarket cams someone needs to do different intake/exhaust cam positions to find best overall torque curve.

nismology

iTrader: (8)

The basis of my original post is that the intake cam should be retarded for better top end power. I don't understand what you're trying to say.
You're not mistaken. I said the same thing in the original post and i'm fully aware of what advancing/retarding the intake cams does, hence this thread..

nismology

iTrader: (8)

Bump...i consider this important to you guys thinking of doing this swap in the future. Cam timing directly affects what the powerband will be like and the current cam timing leaves top-end power to be desired. It's as simple as retarding the intake cam a few degrees or so.

JClaw

iTrader: (17)

Yeah after reading your previous posts I dont want to ever have the static off the shelf cam timing ever again.

Broaner

iTrader: (10)

Very interesting info and I'm following and learning and listening as best I can. I still have this question though. "The standard way to do the cam swap involes drilling the new holes XXX degrees in the counterclockwise direction." I've never seen where anyone says what full VTC retard is in cam degrees from the OEM 30 dowel. Please someone point me.

95naSTA

iTrader: (10)

Very interesting thread..
Just out of curiosity, how much is cam timing adjusted by adv/retarding one cam sprocket tooth?