Does the 4.0 kit keep the stock cylinder bores, or does it need to be sleeved? The 4.5 needed to be sleeved, right? Isn't that where a lot of the cooling issues popped up?

Ah, that's not how I read it at all, and I must have missed the parts on the build list. I'll take your word for it since you've actually seen the car.

Yes the 4.0L keeps the stock bore. There is an option to over bore if you so desire but it is not needed.

The 4.5L is sleeved and yes significant cooling requirements were needed to be put in place. The 4.5L generates a lot of heat! I have somewhere around 3 oil coolers lol and a giant 3" thick racing radiator with larger Spal fans.

Yeah I talk to 1slow370 every other day lol and yeah we discuss his build quite often.

If you run a custom intake manifold, why not do twin 70mm throttle bodies of 09+ maxima and custom intakes.

I have no doubt that you can continue with VVEL, just not on a race engine that uses a cam with more lift than the JUN.

I should perhaps preface all my comments with the fact that I am coming for a race mind-set and based on my own project specifications.

I have raced sports cars in Australia since the late 60's, and I have had a fair bit to do in recent years with GT racing.

My opinions (and to be clear - I have not yet built a VQ race engine but will have one during the course of this year) are formed after conversations with Jackson Stewart at Unitech Racing, Clark Steppler at JWT (who builds all the Grand Am Z34 engines), as well as the engine builder for the Nissan Z34 GT4 FIA Endurance series as well as the Z33 GT3 in the FIA Blancpain series and they all said that the VVEL was a complication best avoided for motorsport, so yes, you are correct, you do not need to delete VVEL for road or occasional track use.

However, if you are going to race the car, then VVEL delete is a clear decision to be made on reliability grounds. In my case, my Z34 is destined for Targa rallies and state level sports car championships and VVEL delete for me is an easy decision, but that is from my personal perspective.

The other point is that my selected cam will have 13.8mm of lift and more duration than the JUN kit, another reason not to use VVEL.

I will be more explicit in future posts.

The Z-1 shorty's and test pipes don't make sense after spending all that money,
Full length tuned headers are the only way to go.

With that preface you are absolutely correct! :tup:

From what I have seen on Z1's dyno the Z1 headers make more peak power than the FI Longtube headers...

But from what i read doesnt z1 dyno read 20-30% higher?

Anyone mess with the Magic Screw?

:yum:

Just to weigh in on the header discussion, I'm running the F.I. LTH's and I make 345whp on a dynojet...so same or more than the z1 shorties. I also make alot more in the mid-range than friends that have dynoed on the same dyno with the Z1 shorties.

wow I wish I was getting those numbers.
is that SAE, STD or uncorrected dyno? and what is ur full exhaust and any other stuff that affect power aside from ur tune?

Uncorrected. From my understanding, STD will correct to 60 degrees and 0% humidity. My dyno conditions were 67 degrees with 25% humidity, so I would think my numbers would be alittle higher if coverted to STD. I'm running Stillen G3's, F.I. CBE w/ 18" res, F.I. LTH's, Z1 intake mani, NST pullies, and UpRev tune.

12nismo was there a significant difference with the motordyne manifold vs the Z1 manifold?