Hi there guys, I have a few questions I hope you could answer for me.

 

Car in question is a 1991 60k mile twin turbo 2+2 manual. Has mongoose exhaust pipes, jetex air filter with 140mm diameter 100mm intake and is rated around 340bhp however much value this holds, but I was conservative on size as I didn't know the amount of room I had available to me.

 

Car produced 272bhp at the fly a few years back with the mongoose exhaust at a very reputable dyno in England.

 

1) I was contemplating a stage ECU tune from Z1 motorsports in the states along with their boost jets but the shipping bumps up the cost considerably. Could I get my ecu chipped for less than 300 in the UK to run 15psi and where could I source the boost jets?

 

2) I'm looking to get some block off bungs/plugs for the recirc hoses, however I need to check diameters, I read on an oz forum that they are 34mm and 25mm with the vaccum pipe being 3-4mm or so. Could somebody confirm this please before I purchase plugs? Also is the VG fine with just blocking off the vaccum pipes coming from the BOV's as per most turbocharged motors?

 

3) Re: the intake heater system what is up with it?! Up to 27 or something it vaguely blows from the dash vents and to the feet, and above this is blows to the window. Though fairly forceful when blowing to the window it is weak as hell coming through the dash and to the feet but due to being automatic I have no control over this.. which sucks! Especially when the roof is off :thumbdown: Any mod I can do to increase the power dramatically?

 

Thanks guys, this looks to be a great forum. :biggrin:

Oh wait 1 more question whilst I remember, I have a daft vibration between 40mph and 70mph that feels like the car is about to fall apart hehe, I assume its coming from the 'shaft so is it worth replacing the bearing or do Z's run well with 1 piece shafts?

Hi matey,

From your questions I can see you have done a little research and have some knowledge of what you want but and only my opinion you are comparing what you consider tech knowldge from other similar "turbo cars" all I can say is don`t!

 

Take a clean view of the 300zx engine, its characteristics and how it operates, this way you will not get bogged down in misunderstandings, ie the air filter flow/ size and bov applications, stage tuning etc.

 

To illustrate what I mean take a completely stock 300zx TT that is well set up and replace the eprom along with a method of raising boost to around 14psi and you now have a 350+ bhp car! easy, no magic tricks no been clever with working out this and that.

 

A free flowing exhaust and air filter can be added later or as in your case already has then thats great, but not completely necessary, yes they will work well with an eprom change but do not expect massive power increases from an induction kit on its own.

 

So back to your question, yes eproms and boost jets are easily available here in the UK, a few guys here sell them as do people on e-bay but I would avoid the e-bays ones.

 

The ecu needs to be socketed as the original eprom is soldered directly to the pcb, this can be an issue for some and and so many of the eprom suppliers will also do a service where you send your ecu and they do the conversion for you.

 

Ok so this means now you have to just refit the ecu and fit the boost jets in the turbo actuator pipework to delay the opening of the wastegates and hence raise the boost easy!! well hopefully it is....but only if your engine is set up well any problems with tps settings, timing settings, air/boost leaks, throttle balance or det sensor issues will effect the outcome, and some such as incorrect timing could potentially damage your engine.

 

Now this is why I personally do not advocate the selling of "chips" through the post as the onus is on the car owner for any possible damage caused to their engine, which in my view is a cop out for the eprom supplier who should take full responsibility for their products, just my view of course.

 

 

Jeff TT

As Jrff said you need to get your engine running 100% reliable befor you think of making boost changes.

 

Allan

go for an electronic boost controller rather than boost jets as it is much safer and gives you much more flexibility and control.

As regards the heat, the auto climate was designed by Nissan to give a comfortable cabin temperature, you set the temp and it does the rest.

 

The cabin vents usually operate to get the cabin to a certain temp then return to the feet position. This gives a nice cool head warm feet balance. This was all done with lots of research and I guess most people don't want hot air blasting in their face for long period, thus when the set temp is reached the air is divereted from the face.

A lot of people hate boost jets - I have run my car for years without problem & are faaaaaaaaaar cheaper than electronic boost jets!! :whistling:

 

Heres a write up I done a while back:

 

http://www.300zx.co.uk/forums/showthread.php?t=29063

 

EBC's are a better way to regulate the boost but jets work just fine IMO!

Oh wait 1 more question whilst I remember, I have a daft vibration between 40mph and 70mph that feels like the car is about to fall apart hehe, I assume its coming from the 'shaft so is it worth replacing the bearing or do Z's run well with 1 piece shafts?

 

Could be your centre bearing (easily purchased and fitted) or the universal joint on the shaft (easily purchased and fitted, but may require balancing). My 300 suffered some years ago from vibration due to this, so i changed the bearing, still had vibration, got quoted for uj and balance, too expensive, so opted for a 1 piece platinum z1 propshaft. Car runs fine to date!!

 

Al.

Many thanks for being so supportive guys!

 

Reg the auto aircooling system.. I'm going to write to Nissan hehe, that is some bad planning..When I'm up at 6 in the morning and the ambient is reading -15 I don't want a gentle temperature wafting away at my feet lol! I want it to burn my face :D But if I'm stuck with it I'm stuck with it..

 

 

Regarding the engine tuning, thanks for your comprehensive replies. I'm a bit miffed about the EBC though, I approached Z1 motorsports and they seemed dead keen against using an EBC on the stock turbo's as the boost came in too harshly for them to cope. I've been offered a greddy profec B which seem to be good, but then the boost jets seem a bit easier to install if nothing else :)

 

I think the car is running well, the boost comes in quick and smooth and theres no drop of boost later on, the car idles well and revs smoothly through the gears. I'll check the timing once the snow goes, it should be circa 15 deg right?

 

At the moment the car has tonnes of grunt between 3000 and 4400rpm, but then the power tails off.. which is why I'd like to increase the boost a fair bit.

 

 

Finally - does having the Z1 1 piece propshaft negate the need for the centralising bearing? It doesnt seem all that much more for the propshaft - maybe 150 quid including shipping. If that is more likely to get rid of the noise then sweet, also working on the stock prop seems a tad complex (going by the manual).

You can replace the heating setup to a series 2 heater control and ecu which gives you directional adjustment, I find that set between 23-25 it does blow out the centre vents until the temp is reached.

Many thanks for being so supportive guys!

Finally - does having the Z1 1 piece propshaft negate the need for the centralising bearing? It doesnt seem all that much more for the propshaft - maybe 150 quid including shipping. If that is more likely to get rid of the noise then sweet, also working on the stock prop seems a tad complex (going by the manual).

 

No need for the centre bearing if you go for the 1 piece set up. :cool3:

 

Al.

I think I'm correct in saying that for the one piece setup though its worth checking the gearbox and diff mounts as if they are saggy the two piece with a UJ in the middle does provide alot more compensation for badly alligned components. Where of course a one piece does not!

One piece is much better though, lighter and of course no stupid centre bearing! Just check your mounts first, will stop transmission shunt and all sorts of knocks and clunks from them! Same with engine mounts as well. (Remember these cars like your s13 you have/had are 20 years old in some cases, and nearly there in others!)