Good post Resolute

the cams and VTC are only part of it

the headwork is critical...the intake manifold is critical, the bottom end to go with the top end is critical. Will you see GT3 type power figures? It certainly is achievable, with the full package. Problem is, to date, people have basically been half assing it (understandably, as it costs a small fortune), but that's why you have not seen the good #'s yet

 

If what he's saying is true about the heads being similar in terms of flow, then headwork won't be crucial. It'll help, no doubt, but let's be real here, the cams specs are one of the MAJOR differences.
Understood, but I thought these went w/out saying, personally.
Agreed.

 

I think thats a big "if"

"Flow" is a super broad term - its like "boost" - meaningless on its own

The lift on its own won't reveal that much either - its realtive to head design, manifold design and combustion chamber design. Ever see a 911 chamber? Looks nothing like a VQ's.

I struggled to find the GT3 cam specs....I couldnt

 

so you are saying that all of this work is going to cost a small fortune. what exactly do you mean by that? like how much money would i be looking at?

 

I think we are all on the same page here, in that the VQ could make NA power that rivals the best of 'em- GT3, M3, etc.. for specific output. The IM isn't the best on the VQ and a possible restriction. The tuning is huge to make an aftermarket built engine perform as well as an OEM could.
According to Nissan, the stock VQ heads flow only 25cfm less than the Spec2 race heads made by Nismo, at 12mm of lift. Cosworth says the heads flow a little worse than that, but they also sell a big vlave head that flows 411 cfm at the same lift. I don't know what the GT3 heads flow, but there's no way a NA VQ will find the heads as a major restriction with the Cozzie bolted on. The heads have a nice design too with shallow port entrance and minimal bend, a good IM will help to make a straight shot from the plenum to the valves.
The GT3 cam specs are the replacement cams sold by Schrick. According to them they are stock replacements for the 996 GT3. They have the option of running a 292 duration with 11.5mm of lift to give better mid range as an aftermarket option. The GT3 cup racer cams they make run 300 degrees duration with 12mm of lift, so there's not much difference between the street and race trims in terms of cam profile.
The 12:1 compression ratio is a big deal. I don't know if I'd trust many tuners to work with such a high CR, as the room for error is very small.
Z1 hit the issue here perfectly. It's not so much the lack of parts to make good NA power, as the small fortune to do it.
Will

 

how much is a small fortune???

 

as much as it costs do go FI, if not more

one thing to keep in mind (to everyone in general)...don't get hung up on cfm. It's a great way to quote things from a marketing perspective, but intake velocity is far more critical than out and out cfm numbers. Talk to anyone who does head work for a reason, and they'll tell you the same thing. It aint the size of the wave sorta thing

12:1 would be sweet.....all in the tune is right.

So Shrick themselves does not make the GT cams but rather makes copies essentially, as upgrades for 911's? If thats the case, remember too, that having the same lift and duration means nothing...its all about how the lobe is designed. In the Evo world for example, lots of firms have "272's" - but all the truly big power cars run 1 of 2 cams...no mystery why, they simply are the better mousetrap than everyone elses.

The Cossie IM looks interesting indeed. I'll try to get one in to play with, or at least get my machinist to do some testing with once its released

Want to see some big cam specs, I should dig up what I run on my Datsun lolol

 

just found a scan of the cam card from my Datsun build

305 duration, .610 (yep) lift now that's big dog!! (though only 1 cam in this engine....old school L28). Took LOTS of work to get that cam to work in the car...I don't have a single off the shelf part in the whole top half of that motor....but she screams !

 

hey guys, my build will be done in 3 or 4 weeks, i will keep it all updated, i am getting 12.7 to 1 JE pistons, i ordered them today, i will be playing with various cams to see what dynamic CR i can get and see what it puts down. probably just use some eagle rods to keep all the cost down and see if i can do a simple powerful build for a decent price.


i have a dynojet at my shop so i will have good numbers that are legit.

12.7 to 1 is the highest possible with stock heads, my heads are ported though but we will see how all the factors take place. i will be tuning it all with a utec for now but if i see good results, then i will get a full standalone and have individual injector control and monitor the cylinders with indiv. EGTs for each cylinder


i have always been an NA fan and will see what i can come up with.

 

Thats going to be sick!!! Some crazy builds coming out of your shop.

 

I can't wait to see the results!

 

the more I read this thread the more I'm loving it.

I can't wait for the upcoming months to see what kind of na tuning and setup comes out of the wood works. Currently I have all the basic bolt ons. I have considered selling this car for another however I always knew this car's engine is capable of great things. If this community can pull off what I want out of this car then I will definitley stick with this car longer.

I will be contacting the tuner or firm that is able to achieve the 300+ hp to get my car there.

 

I am increasingly interested in this thread.

 

Thats what everyone always says, but then it wanes off because of the cost of NA. The real power in N/A is beyond bolt-ons and thats where people get turned off becase for the same or less you can go single-turbo FI and make more power easily.

I still <3 N/A though.

 

yeah well being a shop owner, i can figure out ways of building stuff and keeping the cost down to produce a lot of powerful NA builds.


i mean, cams, pistons and rods can net you A LOT of power if done right.

 

yeah man, RIP to my motor, heads are still perfect, rods have been sold, pistons are going in a customers car i have at my shop, my block is going in storage until i can find some larger main bearings so i can line hone it, crank is done...

just say no to cometic headgaskets + any amount of power over 600 pretty much the story is, water in oil, oil on main bearings with water in it, and then the oil doesnt do its job so the main bearings get crushed (spun), its all good though, i didnt really have that much invested (if any) on the engine/turbo combo, thats why i really didnt care about pushing it.


i will be building my car all motor for a little while now, try to run some high 11s motor and maybe mid 10s with nitrous but be drivable and raggable, probably put my car up for sale soon after its complete, i mean, i have had this car for over a year now, WTF??

 

Good luck. However, those pistons won't survive without proper cooling. Remember, "every 8-10° F reduction in intake temperature is equivalent to adding one more octane number to the fuel." Also, to further prevent detonation, you'll need to run a colder type spark plug with a larger gap, which requires a stronger ignition system.

It's the butterfly effect.

 

yes sir, i am a few steps ahead of ya


i will have more info plus a write up on it here soon

 

^ No one knows because know one trys new things.

 

That's an inaccurate and unfair blanket statement. Would YOU be willing to shell out 1300 bux just to see what the piston-to-valve clearance is with those cams are? Didn't think so. And there's more to cams that aggressive than just the cams themselves. You need the valvetrain and bottom end to support the type of revs those cams want (not to mention the higher static CR to make up for the lower dynamic CR) so it's a more involved process than you think. More people will start experimenting with more and more aggressive n/a cams, just give us some time....