Hi, Newbie here and have a stack of questions to try and resolve some conflicting advice I have heard / read.....

 

I bought my JDM TT (Auto) 92 model six months ago and have had lots of fun putting 15,000 miles on her already. Everyone here knows it but having owned far more expensive & exotic cars in the past I would say this is the most accomplished sports car I have owned. I try to pinch myself regularly and remind myself it really is a thirteen year old car. My goal is return the car to a 'better than new standard' and to some degree money is no object but I also love a bargain. My driving needs are such (30,000 plus per year) that I depreciate a car to nothing in two years so compared to ferrari's this jap stuff is as cheap-as-chips and better engineered too! Such high mileage also restricts tuning and chassis mods to sensible stuff only so if forum members can help please do..................

 

Ok I already did:- Engine De-limiter / Kph to MPH conversion, Blitz induction, blitz boost controller running 10% extra boost (conservative but see my driving needs), injen hard pipe kit, stillen intercoolers + ducts and THE best additions without doubt were both:- The HKS line controller that 'speed-shifts' the auto box (makes it as good if not better than a manual box-no fluffed changes here). The Mines 'Mild tune' +70hp ECU (secondhand from japan via US Ebay - bargainsville) made a massive difference. The mines ECU is programmed for 97RON fuel so what they have achieved especially with torque is amazing.

 

I have a HKS fuel cut defencer at home but not fitted it having heard contrasting stories about whether I need it or not. To fuel cut defend or not is therefore the first question.

 

Having seen adds for in-line octane boosters how do they work and are their claims of being able to produce 100Ron for 30,000 miles valid?

 

Before I fitted the ECU with the boost controller and induction kit I would get up to 13psi on a good cold morning, after fitting the mines ECU it still makes 13psi but doesn't seem to go any higher. Torque and power is massively better but the question is has the Mines ECU made the boost controller redundant or is the Exhaust now restricting things? The second question is my exhaust is still stock (i want to keep the stock look) and the Mines ECU was mapped for a spec identical to my car except exhaust so.......would it make that much of a difference? I heard that the JDM spec car has a 1.5 inch restricter in front of the cats.......and when I have proposed removing or using racing cats people have warned about blown turbo seals. It has had an auto turbo timer since new and done 69k miles so should I go for a full de-cat system or go the cat-back route? In my mind there doesn't seem to be any point of cat back system if the restriction is earlier in the system but I will bow to experience? Has anyone got experience of either? Should I keep it stock or not?

 

On the chassis side I have fitted the wider UK spec rear wheels (didn't want after market as I really like the stock look) and arriving tommorrow are EBC drilled & grooved discs, red stuff pads and a goodridge hose kit. My next question is what coilovers should I fit for fast road stuff. I regularly travel 300 miles up to the northern coast of scotland (dream drive) and do 300 mile M6 journeys down to Bristol & beyond (nightmare journey). In addition I want to do the odd track day so.........Should I go the Tein route with in car damping adjustment? or the HKS hipermax route. Have any listers got experience of either??? In my heart I probably think that the sotck set-up was probably the best compromise but technology has advanced since then. The US car had in car damping adjustment and you see these ste-ups on (US) ebay has anyone done this upgrade / conversion?

 

I heard there is a diff mod on Euro cars due to higher speed cruising and the demands of the wider wheels. As a regular 300 mile trip 90mph plus driver

do I need this?

 

Similarly an autobox oil cooler upgrade has been suggested what do forum members think?

 

Sorry for the list of questions but as a newbie I will give something back as I do the work

 

Thanks

 

Mines TwinTurbo

Hello mate and first of all welcome!!!

 

The autobox oil cooler upgrade is a MUST HAVE!!!!!!!! You WILL blow your box if youve upped the boost and not done this.

 

The 13psi could be a slight boost leak and exhaust issue but I dont know. Someone will be able to answer that for you.

 

Suspension, if you can, go with the Tein setup, nothing better for Zeds.

Hi, and Welcome :)

 

First thing - Yes to the Auto Oil cooler. Essential for a JDM Auto, on european roads if you intend to do a lot of Motoway miles.

 

 

The Restrictor is after the cats, but I would recomend the Mongoose Cat-back exhaust, as it has the stock look, better flow and still pretty quiete.

 

There is a risk of Failing turbo seals when you reduce the exhausts back pressure, but in reality if the seals are ok, then there is nothing to worry about. If they are about to fail anyway, then the reduced back pressure will speed that along.

 

In-line octane boosters - General concencus is that these are a waste of money gimick.

 

If your unable to get more than 13psi with the boost controller, then its likely you have a boost leak somewhere. (Mines ECU has no affect on amount of boost)

 

Not heard of the Diff mod. Other than fitting the NA Diff ratios for increased acceleration, but I dont think thats what you mean.

Hi mate and welcome to the club. I'll try and answer what I can.

Like TMTTPub and Legrath have said, aftermarket autobox oil cooler is a must before you do anything else!

Decatting has always been a touchy subject - the general consensus is that if youre rear seals were on the way out, they will go pretty much as soon as you decat. If your seals are fine, then they will decat fine too. I decatted 2 months ago and not had the dreaded blue smoke (yet).

As far as the ECU and boost controller go - you need them both - the boost controller is the only thing that can up your boost (bar jets but you obviously dont need them), and the ECU (Mines :bow: ) provides the correct fuelling at higher-than-stock boost levels. Stock ECU generally means detonation at high boost :(

Octane boosters - crap.

phew i need a beer.

Thanks guys.........Anyone want to buy a HKS Fuel cut defencer !

PS check US ebay for Mines ECU's secondhand from japan they are total bargain prices, come up every month and programmed for 97ron fuel...........

The diff mod you refer to is probably the cooler that is fitted to Euro spec cars. I don't know of any one who's fitted one to a Jap car, but I do resollect someone removing one from a UK. Overall I guess they're not so important. Gearbox cooler is though - the stock one is effectively useless.

I read in the 300zx book - (enthusiasts guide) that they fitted the diff cooler after autobahn testing during euro model development. Given that I regularly do 300mile journeys at 3AM Motorway speeds I need to investigate further perhaps a UK Diff assembly - Gulp? I am picking up a complete urethane bushing kit on friday so maybe I should make this UK diff cooler upgrade part of that work.

 

Does anyone have a how-to link for the auto-box mod?

 

Thanks