Nissan 300ZX TT 400HP straight pipe? Mod tips?

N

NzMods50

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Hello everyone.

So i picked up a 1992 Nissan 300zx twin turbo.

Its currently putting out 400hp with a central 20 ECU, remap, 4" twin kakimoto racing exhaust, hks induction kit, blitz dump valves, turbo boost pipes have been fitted with 1.5mm jets and cold sparks plugs.

Do you guys think this would benefit from a straight through pipe removing both cats? i was thinking it would probably benefit the engine slightly and hopefully make it sound a bit better. And from what i can tell its perfectly legal to straight through a 1992 vehicle in the UK.

What other mods do you think would be beneficial to performance?
im happy to spend a fair bit on it.

Also interior, is there any interior kits for the 300zx? i really would like it covered with leather ideally and any other interior mods you can suggest would be great.

Colour is mat black.

Thanks
 
Greetings and welcome to our TorqueCars forum :)
We do have some very knowledgeable people on here with regards to these low flying Jap missiles, I am sure someone will be along soon who can help you further.

Good luck
 
Love the look of the late model ZX |B

Am a bit confused by "1.5mm jets " and assuming that it is a bleed off of the pressure to the waste gates to delay them opening to increase the boost pressure over the factory setting ???

Do you have a good boost gauge and what is the maximum pressure reading?

Re "cold plugs" are they needed as if they are too cold it will lead to fowling so I would pull a couple and read them to see if they are really needed.

I think you mean to say that the exhaust has twin 4 inch tips as don't think that it has a full 4 inch system from both of the turbos? It's not the tip size that does anything BUT the diameter of the whole system from the turbine outlets that counts when it comes to making power.

Re removing cats Is that legal and will it still pass MOT ? otherwise fit high flow sports cats.

Are the "blitz dump valves" aka blow off valves recirculating or to atmosphere as if the latter it will lead to over fueling when getting back on the gas IF the factory air flow meter is still in place?

Please correct me if wrong as we need accurate info to be able to give the best advise. :)
 
Hi and welcome. I concur with our antipodean chum re spark plugs and exhaust. 'cold' spark plugs doesn't tell us much. How many grades colder than standard plugs are they?

A 4" exhaust would be too much, especially on a 400bhp twin system. Extra weight and reduced gas speed which could result in increased back pressure, which is never a good thing. Hopefully, it is just the tips :)

Straight through exhausts are not illegal as such, but if they are noisier than than OEM exhaust it is possible that it will fail the MOT, as this states that any aftermarket exhaust must NOT be louder than the OEM version. Depends on how friendly you are with your local MOT station :)

Also, it is unlikely that a car with the cat removed will pass the emissions test. For road use I can't see the point as the increase in power will not be significant.
 
Remember it is a 3.0 litre V6 so @1500cc per turbo a 2.5/2.75 inch MANDREL BENT system from each turbo with a straight thru "hot dog "resonator that has PERFORATED and NOT flow reducing LOUVRE'S internally app1/2 way along with a rear muffler/black box (as you poms seem to call them :) ) with the same internal construction will/would allow the turbos to work more efficiently and get more power to the wheels .

The tip size can be whatever takes your fancy as long as it is not smaller than the rest of the system

IF this was my car that would be one of the first mods carried out ;)

Remember the only restriction in a turbo cars exhaust system should be the turbine housing itself.IMHO

PS Steve I like being a called a "chum" |B
 
However, chum is also a dog food and what they throw into the see to attract sharks :)

We older wrinklies tend to call them silencers over here, the youngsters use back box. Americans use muffler.
 
Shark attractant is called "burley" here.
I'd like to think that we are " old chums" even though we have never met :)

Now back on track to the OP' questions
my mod list
1 front mount IC upgrade
2 have injectors cleaned and flow tested
3 Install new fuel filter
4 remove ,clean reinstall the in tank fuel pump/pick up
5 install an adjustable boost control
6 have car dyno tuned/mapped at the MAXIMUM boost pressure you intend to run to find out the injector duty cycle as well as the AFR'S to ensure that they are safe for the power output.

NOTE IF you have it dynoed at say 15 psi DO NOT wind it up higher UNLESS it has been tuned for it as things may go BANG :eek: .

Am unfamiliar with your engine EMS and it's tuning capabilities.
 
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re the jets are you referring to the ones in the boost pipe or throttle body ?

Nissan used a similar set up in the boost pipe on the the 32 gtr. But there the system was desugned to run at .8bar but the restrictor reduced boost to .6 This was done so they could keep to the gentlemens agreement that stock cars were 280bhp or under,
Removing or changing the size gave an an immeadiate power incresae because the system had been designed to run that
This may not be the case with the zx but in addittion I believe the zx also had jets in the throttle body .These may be because nissan used the same parts on lots of models and these jets restricted things to the level the engine was designed for . If so changing these without supporting mods amd tune would be a road I woudnt go down .
If you are in doubt ask on a 300zx forum ther answer will be well known and definative.
 
Hello everyone.

So i picked up a 1992 Nissan 300zx twin turbo.

Its currently putting out 400hp with a central 20 ECU, remap, 4" twin kakimoto racing exhaust, hks induction kit, blitz dump valves, turbo boost pipes have been fitted with 1.5mm jets and cold sparks plugs.

Do you guys think this would benefit from a straight through pipe removing both cats? i was thinking it would probably benefit the engine slightly and hopefully make it sound a bit better. And from what i can tell its perfectly legal to straight through a 1992 vehicle in the UK.

What other mods do you think would be beneficial to performance?
im happy to spend a fair bit on it.

Also interior, is there any interior kits for the 300zx? i really would like it covered with leather ideally and any other interior mods you can suggest would be great.

Colour is mat black.

Thanks
Hello everyone.

So i picked up a 1992 Nissan 300zx twin turbo.

Its currently putting out 400hp with a central 20 ECU, remap, 4" twin kakimoto racing exhaust, hks induction kit, blitz dump valves, turbo boost pipes have been fitted with 1.5mm jets and cold sparks plugs.

Do you guys think this would benefit from a straight through pipe removing both cats? i was thinking it would probably benefit the engine slightly and hopefully make it sound a bit better. And from what i can tell its perfectly legal to straight through a 1992 vehicle in the UK.

What other mods do you think would be beneficial to performance?
im happy to spend a fair bit on it.

Also interior, is there any interior kits for the 300zx? i really would like it covered with leather ideally and any other interior mods you can suggest would be great.

Colour is mat black.

Thanks
90’ N/A Fairlady jacked for ten years I bought from my father last month. I am in need of a shelter/garage to work on it what is there a best and best value? I also would like to know what to look for once I pull the engine, rebuild kit? I’m does anyone have a working HICAS system?
 

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