Sneak peek at gutted plenum dyno results.

[Jason84NA2T]

grahfz wrote: do I smell a second 'crazy-fast z' in the works?

http://www.redz31.com/pages/mods.87.html

It's going to be my entry for the $2006 challenge. With a little engine work fit into the budget we hope to get it to run a mid 11 my making 400+whp on boost alone. If it needs nitrous we might have to work that into the budget too. Purchase price of $2400 - $1003 sold in parts means I have about about $600 to work with to make it ungodly fast. The setup is there for making straightline power, the car looks good enough, but I think it could use some suspension or it won't compete in the autocross event.

In order to place we need a fair autocross time, an 11.49 or faster on the strip and to have it looking drop-dead beautiful, so if it's not doing that by the end of the summer then there will be no point in entering it.

You can see the 05 challenge results here (I'm the dude on the right):
http://www.redz31.com/coppermine/thumbnails.php?album=6

[grahfz]

have you considered air-bags in the springs? air lift 1000 kits are running for 66$ on summitt.. I think that I've only seen one or two cars on the board running them in all these years... I don't know if they actually help or not..
need to do some more reading.. but hey, for 66$, I'm more than willing to test them out..

[Ken in AZ]

grahfz wrote: have you considered air-bags in the springs? air lift 1000 kits are running for 66$ on summitt.. I think that I've only seen one or two cars on the board running them in all these years... I don't know if they actually help or not..
need to do some more reading.. but hey, for 66$, I'm more than willing to test them out..

could you linky those kits for me, I have no idea which kit to buy for the z31

thanks

[grahfz]

neither do I.. yet.. they make kits for nissan suv's though.. wondering if any of them use the same spring sizes...

at the worst, I figured that I'd call them with spring measurements and get a close kit..

or, I can go to one of the many many 4x4 places around here that are listed dealers for them, and have them match me a kit up..

[craZed]

Jason84NA2T wrote:
It's not a R as far as I can tell,.

Try reving it in neutral and then kill the ignition.Listen for the turbo
spinning.

I did that once and we could hear the turbo spin for
about 40 seconds!
Also the R series have shorter center sections.When I was mocking up the fitment, I noticed I gained about 1.5" worth of clearance between
the compressor and the motor mount.

[j30_vg33et]

Yes, well, back to the intake manifold talk...

I did a little testing yesterday with the local dealers Consult. I didn't get nearly all the data I was looking for due to some cock-blocking techs, but here's some interesting stuff.







So, the bottom line is that with the valve closed, the manifold moves a bunch more air at low RPM. Approaching 7k, the flow evens out, which may very well mean the plenum volume, or some other limiting factor is coming into play. Throttle size, whatever.

Also of note: The new 8.5:1 VG33 + ported heads + JWTS2 cams moves the same amount of air at 8-9psi as the old 9:1 VG30 did at 15psi. Time for a bigger MAF.

[Jason84NA2T]

That's very cool to see logs on the airflow difference! Interesting to note how much of a difference it actually makes; that's substantial.

[G-E]

veeee--tec y0

[grahfz]

Also of note: The new 8.5:1 VG33 + ported heads + JWTS2 cams moves the same amount of air at 8-9psi as the old 9:1 VG30 did at 15psi. Time for a bigger MAF.

Interesting.. I had mine up to 15 on the stock t3 for a night or two ;D

[j30_vg33et]

Yeah, that's the difference between a (real) turbo and a hair dryer...

BFWIW, I've got an early development GT3540. It's the same turbine as the GT35R, a slightly larger turbine housing (.82 A/r + extrude honed + coated), but a slightly smaller trim on the compressor (50 vs. 56).

All-in-all, much better than the T3/T4 hybrids out there. By all means, a good turbo is one of the best upgrades out there. Next to maybe software.

[j30_vg33et]

Jason84NA2T wrote: That's very cool to see logs on the airflow difference! Interesting to note how much of a difference it actually makes; that's substantial.

Hey Jason,

Could you do a datalog of airflow vs. RPM @ 8ish psi? I'm sure we could kluge some MAFv correction factor to estimate the difference in flow between our configurations.

[acabtp]

hey, how 'bout them results?

[Jason84NA2T]

acabtp wrote: hey, how 'bout them results?

I'll get to it when I start to actually care again.

Maybe this year, maybe not.

[G-E]

so what is it about wideband kits that crap out, you aren't the only one, and it seems to happen within 6months for most people....

what actually goes out?

[300zxt]

I agree, and for what it's worth I wouldnt own as many Z31's as I do right now if it wasn't for all of the other high performance, highly modified Z31 websites out there including redz31.com obviously. Even more so considering your car is a 2+2 and that's pretty much all we got here, nice to see!