RBlover69

iTrader: (2)

wow, nice numbers man. The mythical 300rwhps barriers are being broken down by more and more tuners in teh USA finally. I wonder what the revup would post with the same setup. Damn. IF we could ever get a package NA that would be not as expensive as FI tuned built etc. IT would be amazing. I would imagine alot of people would be driving 300rwhp NAs around a track rather then going FI. But alas it isnt for the fient either way. Nice numbers once u get control of VTC that should yeild additional poines. I really wish someone would do a revup build. lol But this is awesome. None the less. Im happy that the 300rhwp is being broken by a vq de first rather then a HR. Damn nissan cant let the des and revup engines live a little until we crack the NA out of it. lol

Andres_Miami

iTrader: (20)

I have the Utec, but even if I set it to 8000rpms it won't go over 7000. Apparently is the way it goes with the 05’ model.

nismology1

They run 12:1. But you can't compare the two engines. They have a different combustion chamber design which has ALOT to do with how high the compression ratio can safely be on pump gas for a given motor. They are also running aggressive cams which helps keep the dynamic compression ratio down.

Also, their knock-sensing system might be superior to the Z33's. You never know. You should never say because such and such a car does this, mine should be able to as well. Every car is different.

nismology1

+1

But at the same time, it's not all about static compression. Dynamic compression ratio is much more important and has to do with the relationship between camshaft specs and static compression ratio. The higher the static compression ratio, the more aggressive the intake cam duration needs to be to maintain a given dynamic compression ratio.

rocks

iTrader: (1)

You could probably get away with running about 5-6psi on it with pump gas. That would make it a damn rocket.

Resolute

iTrader: (2)

You wouldn't happen to be Andre of SR20 forum fame, would you? Heard he bought a Z and thought maybe you'd be him... if not, sorry.

I have a set of 996 GT3 heads in my garage right now, and they aren't that different. The combustion chamber design is, well, almost identical to the VQ35DE heads. The GT3 heads are smooth and polished, with a knife-edged intake divider and the guides are machined down flush with the ports, but the chamber is really not much different than the VQ35. Of course, i think the angle of entrance from the intake manifold is a lot better and responsible for the velocity increase over what I would consider the VQ35 of being able to achieve.
Still, increasing the CR decreases the volume of the combustion chamber, and this has a much different affect than simply cramming more boost into the cylinder. Since the air charge will not combust instantly, and will really only burn about 20% of it's charge at the time of ignition with the rest of the charge burnt as the piston begins it's downward movement (and thereby increasing the volume of combustion space), decreasing the minimum volume of the initial combustion space has a greater impact on flame front dynamics than increasing boost pressures. Anyone here have Heywood's book on combustion dynamics?

Adam, this is an awesome build. A whole-hearted congratulations as I wait to see what you do next. I have to second the notion of being the first to offer a NA engine package with the tune included. That engine is absolutely beautiful to look at, and I love the fact that some aesthetic value was considered in addition to your functional goals. Top notch.
Will

Edit: spent the last 10 minutes doing nothing but staring at the engine pics. Man, how freaking cool that engine looks with the painted cam covers, plenum, and crawford headers... Adam, do you have any pics of the engine after installation? Can you even see the cam covers or headers real well? It's Sooooo nice.

nismology1

Good info for sure but I referring to the combustion chamber specifically. And I don't know what to think of the combustion chambers being similar. From what I've heard and read from people that know better, the VQ35 design is less than optimal.

Resolute

iTrader: (2)

I was trying to figure that out as well. I hear "less than optimal" but no explanations. So, at the suggestion of an engineering buddy, I picked up Heywood's book and began reading. It hasn't really answered my question as it is more of a chemical engineering reference to combustion dynamics. It has a ton of chemical energy equations and a lot of good info, but I was wondering more about combustion chamber design, and it really wasn't answered. So, I'm still looking.
Like, the new HR heads have quench areas on the sides of the combustion chamber, and the Nismo heads do as well. The stock heads don't, and neither do the GT3 combustion chambers. Neither do SR16VE heads, which hold the highest NA hp/liter record. So, I asked my machinist and he had several ideas and good info about valve angle and such, but saw no reason why the VQ combustion chamber itself would be considered an issue. Here are the pics of the 996 GT3 cc and a shot of the VQ for easy comparison, I know they are small pics, I don't have any other pics that are less than the 195 Kb for attachments. Sorry to hijack your thread, Adam:

Edit: GT3 head on the right. It's not the one I have in my garage, but it is a stock GT3 head. The one I've got I am picking up from the machinist for a buddy, and is not stock. The cc just doesn't look any different to me. Valve sizes, angle, etc.. are different though.

rcdash

iTrader: (18)

The rev limit increase only works in speed density mode (fyi just in case). There's always Osiris...

Z350Lover

iTrader: (2)

Adam,

Very nice result mate!!! Congrats on that

I really love your red cylinder head covers...

cheers,

richie

Audible Mayhem

iTrader: (48)

very cool adam!!! sorry i have been sooo very busy and havent had time to post on here. graph looks great!!


are you using a rev up lower manifold?? i noticed you have the same weird dip down in the lower rpms. maybe its because of the headers, i did both at the same time...


either way good job!!

Z1 Performance

iTrader: (564)

Everyone when we were tuning, said the same thing...."you know what would kick *** - a single turbo kit, on this exact setup" - could easily be done, but for now, I want to leave it NA, as I already have a turbocharged animal in the stable too

Yes the combustion chamber design has alot to do with things, but dynamic compression is not nearly as critical on an NA setup vs a forced induction setup. I could have easily run higher compression on this if I wanted, but to what end? If you sit down with the automath formulas, the extra bump in compression really would not yield a whole lot, given the rest of my particular setup. Had I run more radical cams, then perhaps the extra compression + extra timing might mean something, but, we did our homework before hand and knew this would work really, really well together. Not to mention, that I did not want to wait for a custom spec piston to be made, so we did this build with all off the shelf parts.

Z1 Performance

iTrader: (564)

I guess you have an 05 track model (rev up motor). If so, you'll need a flash to raise the rev limiter and then use the utec to control everything else. However, you can also run the MAP sensor option vs the std MAF scaling, and gain rev limiter control as I recall, as the newer ecu's seem to not get along with the ecu quite as well as the older cars do. Will also keep you from losing maps, as the newer cars are prone to.

Z1 Performance

iTrader: (564)

Resolute - thanks man. Remember guys, we did ALOT of R&D before doing this build. I've got access to people, and parts that most people don't have, and, I had the patience to do this right from the outset. Every decision was made by my machinist, not by me. I simply gave him the marching orders and said: "Look, this is what I want - a broad power band, pure street car (ie not too high strung) that will be able to rev more than stock, and run pump gas. The stuff I used is the stuff he told me to get...and there you have it. The motor that is in the car was built out of car...during the whole build, I was able to drive my car, since we had complete spares to do the work to. This is the second set of heads we ended up doing, and ended up even better than the first. We've already learned alot with what the VQ can take NA, and the next build we are doing is something that I know has not been done before (no, I won't let the cat out of the bag yet...we'll wait till it's done!) Ultimately, I am hoping that what we learned on my build so far, and stuff we are starting to play with now, will yield a "package" of parts to give people the option when deciding on building an FI setup or an NA setup.

I didn't snap pics of the motor in the car, and no, you really can't see the valvecovers lololol...oh well But, I think once we do the Cosworth intake manifold, they will be very very visible. Only the dyno will tell us whether it's worth keeping though !

Z1 Performance

iTrader: (564)

Nope, stock 04 lower manifold, that we did some work to I have a revup collector that we sent up to my "guru" as well, I'll call him Monday and see what his thoughts are about swapping it. I had a feeling the dip might actually be as a result of the VTC - I'll have to do an Cipher log one of these days and see.

This is the thing with the machinist we use...he's a realist. He has built every motor that we've ever done. He did the motor in my 280 ZX Turbo too, which revs to 9k and makes nearly 600 at the wheels. He has done the motors in our BMW SCCA cars, as well as a few select Subaru and Mitsu motors over the years. He's been building motors for close to 30 years now, and is just an invaluable resource to us. But, he's not a pie in the sky type of builder. If I show him 2 things, and give him my goals, he'll tell me if it's worth it to change something or not. If it is truly worth spending money on, he tells me. If it's not going to yield any significant power or reliability, he tells me that too. Really let's me get down to the thick of things, and do what is worth doing. Those that know me know I am not into just swapping parts for the hell of it.

So, I'll call him Monday and see what he thinks about trying the revup manifold next...easy enough for me to change, so we'll see what the man says

Ritchie - my MUSE!!!!! LOLOL!!!! Seriously, your car is what what made me want to do this in the first place. I just couldn't let the Aussies have all the fun

Lawn Dart

iTrader: (4)

Congrats Adam! I'm looking forward to pictures or videos.

I noticed that you are revving smoothly all the way to 8000 RPM. If I remember correctly, Z350Lover also used Nismo valve springs, but changed to Ferrea valves & springs after having a problem at high RPM. Do you think that you have had no problems because you have less agressive cams or maybe because you have better piston to valve clearance?

Andres_Miami

iTrader: (20)

Nope, I have 05 enthusiast. From what I understood, you only can use the sped density mode, when you have forced induction. Does someone know about this? I don’t what to damage this thread, please PM me. Thanks

Z1 Performance

iTrader: (564)

the NISMO springs are rated to be used with a cam featuring max lift of 11.0 - these cams are a 10.5. I think Ritchie was using them with Spec 1 or 2 cams, which have a higher lift

Z1 Performance

iTrader: (564)

check the tuning forum, its discussed at length in there

Audible Mayhem

iTrader: (48)

i ran my NA car in speed density mode. its WAY more consistent for sure.