I have made the (momentous) decision to convert from auto to manual. After having an auto for 3 years and gradually upgrading engine & suspension i now reckon the time has come to convert because the manual surely offers that much more control, involvement and power.

 

What's the opinion on the forum? Am I the first in the UK? If you have dunnit, are you pleased you did?

 

P.S. See my auto box in the sale/wanted forum.

 

Hi,

I thought that the engine on the manual gearbox turbo cars has different variable valve timing, cam profiles,fuel injection and ECU, than the less powerful auto.

JEZ

 

i have a manual and they are definatly better,

after going in a manual and then an auto and then bacvk in a manual straight after, you can really feel the difference, (just my opinion of course) but the manual just feels far more alive.

just do it man

 

I thought that the power put to the gearbox split them, have I been misinformed ??

 

I think the only differences are the ECU, Turbo size and general Gearbox related stuff.

 

The Turbos are slightly smaller for more lower end torque.

 

Both SE and Paul Bailey have done the conversion, ring them up and ask them at what price they would charge.

 

I would say manual is the best option on our twisty road, but then again i have never really driven a Auto really hard round challenging road or track so can't comment on its performance in the hands of a expert

 

Flame proof suit on :)

 

Z ya

 

Nico91TT

 

 

 

 

 

When I got mine I test drove a silver Jap import manual (non turbo) and my auto twin and thought that although the driver appeal on the manual is more I thought the twin had a lot more going for it. But then I haven't driven a maunal turbo !! mmmmm wouldnt mind a go in one of those. The only complaint I have about the Auto twin is the constant back end slide (Rear Wheel Steer my arse !)

 

Horses for courses IMHO. Not surprisingly, we haven't got anyone saying that they have one type but the other type is better !

 

I have an auto. A manual would be more involving on the occasions when I'm hacking around country lanes but that is rare and the ease of use of the auto is a big bonus for me. No heavy clutch and instant power on the motorway without having to move - drops down into second at legal speeds anywhere in this ridiculously low speed limited country !

 

My opinion though is swayed by the fact that I have an auto box with uprated line pressure. The standard auto box felt a lot more mushy and in my opinion it made it more borderline.

 

Dave

 

Coogs,

 

I would recommend purchasing a crash damaged manual example to use as a doner car. This should make the costs a bit more realistic m8. You can then sell the parts you don't need to recover some wonga. I think there is an exact list on TT.Net of all the parts that need replacing. The engines are exactly the same apart from the smaller blowers like Nico said. They spool up faster apparently.

 

Personally, I would prefer to have both manual and auto. I would agree that the auto does not feel as sharp as the manual.

 

Andy

 

Taken from the FAQ section of TT.NET...

 

Does my automatic Twin Turbo really have 20 horsepower less at the flywheel?

 

Yes. I couldn't believe it, based on the performance of the two cars, so I did some research.

I found two quotes from books written about the Z:

 

"The four speed automatic was also available in the Turbo but in deference to the auto boxes longevity, the engines power output was cut back to 280bhp by different camshafts and fuel injection maps. Torque remained the same." From: Illustrated DATSUN/DATSUN Sports Car Buyers Guide by John Matras.

 

and:

 

"For various reasons the 300zx Turbo in some versions is rated at 280bhp. This applies to the Japanese market, where the manufacturers have an agreement to limit outputs to 280, to automatic trans models in the US, which have different camshaft profiles and fuel injection settings, and to the European market 2+2 because of its setting for lower-octane unleaded fuel." From Nissan 300ZX - The Enthusiasts Companion by Ray Hutton

 

I asked people I know at Nissan USA and Nissan Japan to confirm the horsepower rating of TT's with automatic transmissions.

 

The response I got from a contact at Nissan USA was:

 

"Aside from minor changes in the ECU, the cam profiles & turbos are also different between the M/T & A/T models. The A/T has 240 degree intake cams & 248 degree exhaust cams (the M/T has 248 degree cams for both intake & exhaust). Also, the A/T uses smaller turbos for more responsive low speed acceleration (the A/R ratio is 0.63 for the M/T & only 0.54 for the A/T). Even with 20HP less, the A/T turbo is capable of beating the M/T turbo to 100MPH."

 

I checked the fiche in the 'DOCS' section:

 

There were always different ECU's for manual and auto cars.

 

The camshafts were always different on the autos until the 1996 model year, and the part numbers changed three times. In 1996, Nissan discontinued the variable valve timing system, and rated the TT engine at 280 HP.

 

The exhaust manifolds (from the cylinders to the turbos) are the same for all years.

 

The turbos were always different (see Nissan USA comment above). They went through two part number changes on the right hand one, and three on the left hand one.

 

The exhaust housings (which attach the pre-cats to the turbos) were different for manuals and autos only from 9/93 to 9/94.

 

The manual and auto had different pre-cats, and the part numbers changed three times from 1989 through 1995. Both cars used the same pre-cat for the 1996 model year.

 

The H-pipe was the same for both manual and auto cars throughout production.

 

The main mufflers were different throughout production - even for the 1996 model year.

 

The auto has a different radiator, to accommodate the need to cool the transmission fluid. There were no part number changes throughout production.

 

From all of the differences in components, it's pretty clear that Nissan did some serious engineering to get the two cars to perform much the same way even though the auto model is down 20 HP.

 

 

Interesting reading, thanks Jez.

 

Bloody hell Jez, it's like being back at school! lol

 

They obviously take their Z technical information very seriously in the US!

JEZ

 

Hi,

The UK spec autos were officially rated at only 263bhp/269lbft, as against 278/272 for the manual car.

The Nissan quoted 0-60mph time for the UK auto was 7.5 secs...slower than a manual non-turbo!

Obviously you can modify the Turbo to higher levels though.

JEZ

 

How did Road & Track USA get a tt auto to do 60 in 5.9seconds then?

 

Are all road test cars specially prepared?

Willie

 

it all depends really cause some magazines have got 300zx turbos to 60 in 6 seconds, so its all down to the conditions,

 

The above was written by Tom Bell. Some of you saw him at the Zandwoort event.

 

Even if the auto...is still an auto...and lacks the control the driver has in a manual...it's a VERY GOOD auto box.

 

It REALLY shines when you put it into the 400 HP range.

 

The autos are REALLY FAST when coming from a stop becuase of different turbos, and a longer final ratio

 

It's harder to spin the tires in an auto.

 

IMHO....do what I did (or more precisely, the opposite)

 

For the cost of the conversion, buy yourself another Z (I have a manual & an auto), and install JWT chips in it.

 

Then......you can decide....

 

Baiscally, if I go for pure fun, I'll take the manual ....otherwise, if I know I'll hit traffic jams / city traffic, I take the auto

 

Zee you

 

Henri

 

I was given the impression that the Jap Auto TT has a 0-60 around 6 seconds, the only mod on mine is a performance exhaust system which apparently (so I have been told anyway) takes mine to about 320bhp. Anyone know the why the Jap would differ so much from the UK one?

 

Road and Tracks time always seem to be very fast,

 

There was a tread a while back about this, i think we attributed it to Better Drag times in the US coming from hotter stickier (better) Track Surfaces.

 

And the fact that time passes slightly slower in the US ;)

 

Z ya

 

Nico91TT

 

 

 

 

 

 

 

 

 

Um, Jez, can you find any further proof please? LOL J/K m8. Cheers, thats the first I heard of that. Do what Henri said then, just buy another Z Coogs.

 

Thanks for the comments. Henri, you can buy another Z it for about the same as a conversion? Z's must be well cheap in Switzerland, you lucky b*@!%*!.

 

The differences between auto and manual engines are mostly confined to the US models I think. I accept that I won't be getting an exact 1:1 of a manual car, but a converted auto. Smaller turbos are no big shakes- the boost level will have more impact. I may upgrade them and the cams one day anyway.

 

For the twisty bits an auto is just never in the right gear at the right time, even with manual shifting. I've always felt the gearing to be too high, and the manual is generally lower (auto 3rd = manual 4th) Final diff ratio is the same.

 

I'm found a complete car to cannibalise and so I'm going in. I'll let u know how it goes. Did I mention I was selling my auto box..?

 

Hi,

Don't forget the US turbo cars are lighter 2 seaters with slightly more HP.

I never believe road test times of turbo powered cars, as they are so easy to boost for the best times for the manufacturer.

JEZ

 

Anders...my figures were sourced from TT.net, 'Nissan 300ZX..enthusiasts companion' by Ray Hutton, and 'Datsun280/Nissan300ZX'by Brian Long...both intersting books if you like ZX's

JEZ

 

I bought my second TT for Sfr 9000 (about 3600 GBP)

 

It was NOT in a perfect condition.

 

Hole in exhaust

Rear Wing damaged

No brake pads

Warped front rotors

Tires were gone

Unknown mileage (dash was changed)

Stereo KO

Dirty inside

NO Auto oil change

Last Oil change was done....who knows when

 

BUT...

Timing belt WAS changed

It had NO Ecu error codes

Ran well

NO Auto box error code

 

So...I bargained until I got the price right...and I fixed almost every other problem with parts I already had at home.

including

 

new brake pads

new tires

new rotors

new stereo

cleaned the car

oil change

auto oil change (damm, THAT was expensive)

 

In total...my cost for the car is probably well below the GBP 5000 mark....

That's how you do it !!!

 

Zee you

 

Henri

 

Jez

I'm devastated. 7.5 Seconds to 60 for my Z ttauto! And Autocar says 5.6 for a manual. Have to say I never checked so far. This means my 2 litre family saloon is quicker according to Autocar at 7.3 seconds. Life will never be the same again. I'd rather cling to the dream and believe 5.9 as found for the 280hp auto tested in USA and what Henri says about the auto being quicker to the ton. So there!

 

You're a brave man, Henri. There's no way I'd test how well a TT with no brake pads ran!

 

Nobody's picked up on the fact that the ecu takes feedback from the auto box - isn't that why its different????