buying a import 300zx this weekend,

 

plan on increasing the boost a little. Asume they run 10PSI standard??

 

can the standard fuel pump handle say 14PSI??

 

my S13 needed a walbro, as the standard one cudnt provide enuff juice on demand (feel car holding back)

 

also is the ECU have fuel cut? (its a Jap car, converted to MPH)

buying a import 300zx this weekend,

 

plan on increasing the boost a little. Asume they run 10PSI standard??

 

can the standard fuel pump handle say 14PSI??

 

my S13 needed a walbro, as the standard one cudnt provide enuff juice on demand (feel car holding back)

 

also is the ECU have fuel cut? (its a Jap car, converted to MPH)

 

Your fuel pump will be fine apprently they are good for 600bhp.

 

If your going to raise the boost i would advise to chip your ecu if it isnt already done otherwise your come into a few problems Detting etc.

 

Give DTA i shout in the traders section he will sort you out with a chip to suit your mods.

thanks,

 

think the ECU is standard, but its been converted to MPH, will it still be restricted to 110MPH? or does this go out the window when they get converted?

you need super unleaded if running over 350bhp.... known by experience! and im a woman...lol

you need super if its a Jap 300zx anyway! (and by super, V-power, none of this tesco 97 ron shite!)

well they are 276 standard arnt they,

 

this has twin exhasut and filters (still has cats) asume it will be 286~

 

once de-cat, plan on raising the boost a touch, so car would be about 320??

 

thats my estimate.

 

 

comparing to my 200sx, car was transformed by increasing the boost by

5PSI, and thats just a singe turbo car.

 

would imagine a big difference on a TT.

PS its ok to use normal 95 isnt it?

 

just wont run as good as 97.

 

or just use normal 95 + octane booster

buying a import 300zx this weekend,

 

plan on increasing the boost a little. Asume they run 10PSI standard??

 

can the standard fuel pump handle say 14PSI??

 

my S13 needed a walbro, as the standard one cudnt provide enuff juice on demand (feel car holding back)

 

also is the ECU have fuel cut? (its a Jap car, converted to MPH)

 

At 14psi, your starting to push the limits of the turbo's! Might be a thing to look into!

 

you need super if its a Jap 300zx anyway! (and by super, V-power, none of this tesco 97 ron shite!)

 

Im sure he's right you know! :nono:

PS its ok to use normal 95 isnt it?

 

just wont run as good as 97.

 

or just use normal 95 + octane booster

 

you really need high octane - especially with warm weather, you will easily get detonation... more so when you up the boost.

hmm, ok.

 

well i leave the boost at the mo then. havent got a chip for the ECU anyway,

 

 

il just get it de-catted just to free everything up.

 

when i chip it, and turn the boost up, il use higher octance fuel.

 

as its standard at the moment, 95 UK petrol should be fine yea.

At 14 psi it's not really the turbo's that are maxing out, it's the injectors.

 

You can run 14psi on stock injectors, turbo's.

 

But I don't think the mapping on the standard chip was coded for boosts higher than 10 - 11 psi.

 

If you want to up the boost you need to have the following:

 

Upgraded exhaust, induction kit, after market chip. Once you have those you can use boost jets or a boost controller, but running more than stock boost I would reccomend getting an aftermarket boost gauge if you are going to use boost jets, or a visual display boost controller.

I didn't think the engine would be able to hack it after 14psi, even with the bigger injectors?

yea ive tuned my S13, so i know the things required.

 

my S13 - Air filter, exhasut, de-cat, walbro fuel pump, boost controler, and boost gauge to see what boost your running. stage 1 chip to remove factory fuel cut, and to provide more fuel for the increased boost.

 

The Z needs the same principal, apart from the fuel pump which is good enough (found out from this thread)

 

the boost can only be increased so far, without the injectors maxed out. thats when you go to stage 2 tuning, along with larger intercooler, and colder spark plugs.

 

just wondering about the standard UK petrol ona standard Jap car at the mo...

I didn't think the engine would be able to hack it after 14psi, even with the bigger injectors?

 

bluddy hell, its a 3.0V6, the engine can handle a LOT more power than 2 Garrett T25s,

 

think about HKS turbos etc. im sure the VQ35DETT can handle 400HP on standard internalls..

 

its the ECU would need chipping to "allow" the increased power

bluddy hell, its a 3.0V6, the engine can handle a LOT more power than 2 Garrett T25s,

 

think about HKS turbos etc. im sure the VQ35DETT can handle 400HP on standard internalls..

 

its the ECU would need chipping to "allow" the increased power

 

 

The pistons are renowned for failing on the piston lands and going to about 14-15psi is putting the engine on the boundaries!

bluddy hell, its a 3.0V6, the engine can handle a LOT more power than 2 Garrett T25s,

 

think about HKS turbos etc. im sure the VQ35DETT can handle 400HP on standard internalls..

 

its the ECU would need chipping to "allow" the increased power

 

The thing is chap, unlike alot of the zed's rival cars, the injector CC is relatively small, only 320cc's, so anything close to 14psi the injectors are gettnig close to max duty cycle, which puts a limit upping the boost on OE fueling. Even if you upgrade the injectors to 550cc injectors the Turbos on the other hand can only really go up to 15.5psi before the become highly innefficient and begin to super heat the air.

 

When it comes to the strength of the internals, 380 fwhp is pretty much the limit. Some peeps have pushed it a bit further, but it hasnt been long before things go pop, which in turn is met with of a chorus "we warned you".

 

Fueling, yeah you can run 95 on standard boost, but you ARE running the risk of detting, especially in warm weather. For peace of mind its worth running Vpower.

 

HTH

 

Nick

thanks mate,

 

il just decat i think. Safer then isnt it.

 

(im a bugger tho i know il end up turning the boost up!)

 

thanks for the responses guys, as you can tell, im knew to the 300zx,

 

hope il enjoy it!

The pistons are renowned for failing on the piston lands and going to about 14-15psi is putting the engine on the boundaries!

 

But isn't this to do with the fact that the injectors are maxing our so you are running lean on that much boost.

 

I know there was a lot of debate about how much the stock internals can take. Some claimed it was good for 450 bhp, and others although maybe a little dilusional claimed 600bhp. I guess it comes down to how old and what condition your engine is in. A brand new stock engine may be able to hold a lot of power, but we are talking about 15 year old engines now and in most cases 15 year old pistons.

 

You put a granny into a weight lifting competition without strenghening her bones, she's gonna snap !

thanks mate,

 

il just decat i think. Safer then isnt it.

 

Well that's not entirely true :D

 

by removing the cats you are removing the back preasure from the exhaust system. The standard turbo's have oil seal rather than ball bearing seals.

 

What tends to happen when you decat is that although you allow a more breathable engine you are also taking that little bit of back pressure away. Which means that you may (and I say may as I don't believe it's actually been proven) speed up the lifecycle of your turbo seals.

 

Put it this way, These cars where designed and built with a lot of time and though put into the mechanics, the body, suspension etc etc. If you start modifiying one part of the engine to improve the power, then you will put more strain on another component.

 

There is always a bottle neck when it comes to modifiying the engine. You need to think about how much you want to spend before thinking about how much power you want.

The thing is chap, unlike alot of the zed's rival cars, the injector CC is relatively small, only 320cc's, so anything close to 14psi the injectors are gettnig close to max duty cycle,

 

Are they 320cc or 370cc ?. I was sure they were 370's

But isn't this to do with the fact that the injectors are maxing our so you are running lean on that much boost.

 

I know there was a lot of debate about how much the stock internals can take. Some claimed it was good for 450 bhp, and others although maybe a little dilusional claimed 600bhp. I guess it comes down to how old and what condition your engine is in. A brand new stock engine may be able to hold a lot of power, but we are talking about 15 year old engines now and in most cases 15 year old pistons.

 

You put a granny into a weight lifting competition without strenghening her bones, she's gonna snap !

 

It can be the injectors on the edge of their limits but I don't think the pistons are much cop either!

injectors are 370cc

 

In my eyes 10 year old stock pistons are only good for 10psi (if that) after that you can expect quicker wear thats of course if youve got a heavy foot, i know that some on this forum say they have been running 15psi for 2 years with no probs but have they actually taken it for a thrashing around a track at full throttle for 15 mins? I suppose bigger ic's injectors and rad will see a little extra headroom but for how long?

All it takes is a long blast on the throttle with a bit of extra unwanted heat, a weak injector, det.... and BYE BYE

 

I ran mine at 14psi expecting my rings to snap and when they did i had an excuse for an uprated build which im doing now... cant wait woohooooo

In my eyes 10 year old stock pistons are only good for 10psi

 

So is that the great piston age/ psi boost ratio relationship only whispered by the great HKS oracles in the foothills of the Himalayas :D

No its the great free flowing thought of the japanese chopstick holding guru on the long right hander of tokyo drift :D

Hi

 

Just doing a De Cat on a Jap spec with an original exhaust may not give you what you want. The exhaust is also restricted in the section just after the Cats. If you split the exhaust have a look. Zed World showed me when they fitted my Mongoose system. Apparently it was part of the gentlemans agreement in Japan not to exceed a certain BHP limit and they knew people would try a de cat so they restricted the exhaust as well.

 

I left the cats on to protect the turbo seals but the Mongoose system certainly made a big difference to overall breathing

 

If you want to check, split the exhaust behind the cats and check the interior vs exterior measurements

 

Hope this helps

Its not running lean that is the issue - its the fact that the ring lands are weak after 15 years and collapse under the extra load....