Limits of VG30DETT components and internals

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Initial Z
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Limits of VG30DETT components and internals

Post by Initial Z » Tue Feb 19, 2013 8:20 pm

Hey guys, wanted to start a new thread for tuning z32's and common mods and mistakes
people make while trying to acheive massive power numbers.
VG30's make 300hp coupled with a manual transmission (wouldnt have it any other way)
but they are heavy cars, so power to weight isnt the greatest ratio with these,
hence why i want to make alot more power.
I have done nothing so far to increase over all horsepower,
My mods are strictly supportive to keep it cooler and reliable.

How much horsepower can i safely make with stock internals?

Where is the best place to start

What is the most cost effective (Instant) performance gain

Were did you start?

What has gone wrong when YOU have tried to get power gains?

Hopefully that gets the thread going :)
Z32 2+0 TT Project

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ForemanNZ
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Post by ForemanNZ » Tue Feb 19, 2013 8:39 pm

How much horsepower can i safely make with stock internals?
- The internals are pretty strong to begin with, but what will probably let you down first is the injector size, then its all over.

Where is the best place to start
- Theres a manufacturing defect in the block called casting flash - this restricts coolant to the #6 cylinder, which will then blow up spectacularly if you push it. A home build hill climb team I met had several engine failures with a VG30DETT where it would blow a hole in the block, always on the #6 cylinder. You will need to strip your engine down to fix it, but you will only need to do it once, then the block will be good for over 1000hp

What is the most cost effective (Instant) performance gain
- welding tips in the wastegate lines, about $10 all up, which will change your boost, but use a boost gauge to check your boost, and don't let it get above 14psi or the ECU will think theres a problem.

Were did you start?
- I bought my first Z32 in 2001, a 2+2 NA, and the first thing I did was get rid of the airbox and replace it with a pod filter.

What has gone wrong when YOU have tried to get power gains?
- Old intake hoses were perished beyond belief, but you would have expected them to be ok since the hose clamps were further up the hose. One things is for sure, is that high pressure air will find the smallest hole to leak out through. Bit the bullet, replaced with silicone, all fixed.

http://www.motoiq.com/magazine_articles ... art-1.aspx
AKA ZFETSH
Now armed with a Z32 2+0 NA

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ZMAD
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Post by ZMAD » Tue Feb 19, 2013 9:20 pm

Wow! Very interesting reading. Makes you want to build up an engine.
All Nissans are racecars.

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ZILVER
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Post by ZILVER » Wed Feb 20, 2013 8:29 am

How much horsepower can i safely make with stock internals?
500HP has been achieved with stock internals and stock turbos. But its the durability issue which should also be taken into account.

Where is the best place to start
For performance gains - Pod filter, Aftermarket exhaust (cat-back) and ECU offer good results considering the cost.

What is the most cost effective (Instant) performance gain.
An aftermarket exhaust frees up a fair bit of HP, but its the combination which dictates the potential gains from upgrades.
An Electronic Boost controller can be pretty potent as it permits increase boost.

Where did you start?

A TT in 2000 ~ or should I say the Factory service manual :(
It got returned and for a daily I got a mint condition NA which got eventually got treated with everything short of NOS.

But if you mean as a basis of modifications then: Tyres & brakes (These shouldn't be over looked)

What has gone wrong when YOU have tried to get power gains?
Girl friend got a hold of my bank statements

Hopefully that gets the thread going
There is already something of an international cult following for the Z32.
Twinturbo.net is a massive forum with everything you wanted (and didn't) to know about the Z
I think you may also find this a worthwhile read:
http://www.automotiveforums.com/t419768 ... _tips.html
Last edited by ZILVER on Wed Feb 20, 2013 9:00 am, edited 2 times in total.

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us2
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Post by us2 » Wed Feb 20, 2013 8:34 am

!972 240z
Retirement is great. Growing old sucks.

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ZILVER
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Post by ZILVER » Wed Feb 20, 2013 8:58 am

I'd consider it gospel too.

mikec(nz)
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Post by mikec(nz) » Wed Feb 20, 2013 8:07 pm

Yes that 'little speel' is some of the best advice out there. A little bit out of date but 99% good.

ECU go aftermarket LINK/Mega squirt/MOTEC

Injectors go 740, 555's too small and the cost is pretty much the same.

Split length down pipes and MS Manifolds good power gains.

3" dual exhaust no question

Seems to be a lot of gain with Z1 massive intercoolers and 2.5" intercooler piping, avoid front mount intercoolers.

Turbos the GTX 28 series seem a good option currently.

Where did I start? JWT chip back in 2000

Most cost effective/instant - Well hard to say but I reckon carbon fibre driveshaft/lightened flywheel was my favourite combo - amazing increase in turbo spool

What has gone wrong - everything at one time or another, overboring (and it was only 1mm) was my biggest and most expensive performance mistake. Rebuilding rather than replacing brake master cylinder was by biggest and most expensive overall mistake.

the NZ300zx forum has lots of info but twinturbo.net is the bible.

Initial Z
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Post by Initial Z » Wed Feb 20, 2013 8:43 pm

The z32 virus is definately spread wide through the forum,
I was just disapointed that the z32 area of the forum was so
Threadless, besides a few links to troubleshoot.
Definately would rather hear personal experience
And thanks to all your input making the right decisions
will be alot easier without making the same mistakes.
surely will help new z32 owners/enthusiasts in the future.
Z32 2+0 TT Project

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ZILVER
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Post by ZILVER » Thu Feb 21, 2013 10:54 am

I was just disapointed that the z32 area of the forum was so
Threadless
The NZ Z32 300zx.co.nz forum is certainly more apparent for posts. But dont be a stranger on this forum - the Z-Club site is certainly beneficial for meets/social activities/events/track days. This forum is where I made many friends which only fueled the Z obsession further.

Mike/Anyone (I'm wondering this myself as have mixed reports) - but will larger cc Fuel injectors ie 740cc have any negative tuning issues considering if deemed overspec?
Though I have no conclusive reports to base this assumption on - I ponder that the larger cc injectors would not permit a smooth idle, and cause it to run richer/difficult to tune compared with 555cc if thats all the upgraded turbo/modifications require?

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ForemanNZ
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Post by ForemanNZ » Thu Feb 21, 2013 1:19 pm

Injector cycles don't work on letting in a certain amount of fuel per cycle, they stay open for a set time then close, so a larger injector would be harder to get a precise measure of fuel for each squirt, depending on how tunable your ecu is.

Really crappy example, but
If you took out a 370cc injector and put in a 740cc injector, without changing anything in the ECU, you would now get twice the fuel into the combustion mixture.
But if your ECU was only tuneable in 0.1 second increments (go with me on this!), the 370cc injector could step down to 37cc per second, but the lowest the 740cc injector could do is only 74cc per second, making it alot harder to get the right air fuel ratio.
AKA ZFETSH
Now armed with a Z32 2+0 NA

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ZILVER
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Post by ZILVER » Thu Feb 21, 2013 4:31 pm

Thanks for the explaination there Karl. So my assumption is kinda true being that larger injectors would "bleed" excess fuel at idle as its to difficult to match the 370cc flow rate - particulary at idle causing rough/rich idle. Is this the only negative with selecting the larger cc injectors?

mikec(nz)
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Post by mikec(nz) » Thu Feb 21, 2013 7:57 pm

but will larger cc Fuel injectors ie 740cc have any negative tuning issues considering if deemed overspec?
No. A decent ECU will allow smooth idle, in fact with the 700cc injectors in the race car (which are actually really old RC Engineering remanufactured injectors) we found it was a bit lean at idle causing it to hunt.

Sure if you put in big injectors without changing the tune it will run super rich (if it runs at all). All my Z's have 700+cc injectors and they all idle fine.

This 'myth' is probably from when ECU's and injector technology was just starting.
Injector cycles don't work on letting in a certain amount of fuel per cycle, they stay open for a set time then close, so a larger injector would be harder to get a precise measure of fuel for each squirt
While this is true we are talking millisecs and injector duty cycle can be set at 1%, I think some ECU's can be set at fractions of a percent. Again all about quality of injector and quality of ECU. But my real life experience is no prob.

Now maybe if you were running 6 x 2000cc injectors might be an issue.

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