Whats it like then?

[PaulFitzwarryne]

Don; really enjoyed your threads on the new engine. What did they finally do to it?

I have gone the nearly the same route. Mine is a 1985 12A T kept mainly stock other than a large front mounted intercooler and a microtech ecu.   Backdated the radiator and oil cooler to the series 2 which were more efficient, important with an oil cooled turbo. It produces just over 200hp at the wheels but keeping down to stock turbo and porting means it is a superb daily driver in traffic.

[Don Pamponi]

Well now, as to what they finally did to it - your guess is as good as mine!  Tim seems reluctant to send me a spec sheet.

[PaulFitzwarryne]

Don- It\'s a real problem when your builder does not give you specs because he is afraid someone else will copy his work.

What I have done to my 85 with its 12A turbo engine is listed below. The goal was to have a great daily driver,with performance, handling and fuel economy.

Performance.
1. A very large custom front mounted intercooler sloped at 60 degrees.
                       2. Better efi ecu- a Microtech LT4 using the 12AT distributer and 10mm plug wires.
                       3. Efficient 3” to 2 ½“exhaust with just legal free flowing muffler.
                       4. Light steel flywheel and high pressure clutch.
                       5. Upgraded blow off valve, set at 10psi for daily driving
                       6. K&N pod air cleaner

Efficiency
       1.  Front mounted custom oil cooler, essential for rotor and turbo life.
                       2. Shorter fatter radiator allowing more room for the FMOC.  
                       3. Upgraded Bosch fuel pump and ss lines, with surge tank and regulator.
                       4. Deleted air pump and anti pollution system
                       5. Turbo timer, to protect the oil cooled turbo at ignition switch-off.

Handling
       1. Suspension lowered 1 ¼” for more stability
                       2. Upgraded adjustable Koni shocks and stiffer springs.
                       3. Poly suspension bushes and smaller rear swaybar.
                       3. Metallic brake pads with ss lines, for better stopping power.
                       4. Enkei alloy wheels with Dunlop Formula W10 205 tires.

There are also a host of very minor upgrades ranging from better halogen headlight bulbs to a twin fan belt pulley. The exterior and interior remain stock. However, I use a 6gb mini Ipod and Itrip as an audio improvement.

At the normal daily 10psi boost the output is 210rwhp.  Fuel consumption is 28mpg cruising at 70mph on long trips.

As part of my upgrade I considered porting and changing to a larger turbo, but kept it stock as there is sufficient power for my need, plus she is considered a non-modified car for registration and insurance purposes.

[Don Pamponi]

Got any photos?

I know I\'ve got a TII turbo & ignition & that its ported a lot.

I doubt that the spec is a big secret, its fast, but not in the record books or anything.  I think they must just be very busy.

[PaulFitzwarryne]

Don- will post photographs in a few days time of my car and the 12A Turbo  set up.

I noticed in an early post that the power of the stock 12A T was given as 165hp!@ 6500.  This figure is its JIS hp, which is higher than the SAE hp.  The power of the 12A is 130hp in JIS specifications, which makes the 12A Turbo power about 127hp SAE. What is interesting is the stock performance was top speed 225kph[140mph] and 1/4 in 13.2 seconds, real performance in 1984. All this without an intercooler.

regards Paul

[Don Pamponi]

I\'m rather pleased that Tim didn\'t fit an intercooler.  They are laggy.  The trottle response I have is instant!

[PaulFitzwarryne]

Don- I agree that with an intercooler you do get lag. However, everything is a compromise.

On the positive side,the rotary exhaust air is extremely hot compared with piston engines. For every 11 degrees F you can cool it, power increases  by 1%.  If you have an efficient flowing and cooling intercooler, you can decrease the temperature by 75-80% of the initial increased temperature. For the 12AT I estimated the increase in power was 27% [optimist!].

On the negative side is the high cost of a performance intercooler, and something most people forget- the pipes and silicon hose.

There is a lag in response which depends on the pipe length and intercooler flow specifications. The latter has really improved over time. When we tried a IC on a turbo Lotus in 1971, there was a noticeable lag and I doubt we achieved 50% efficiency. Even in 1986 the efficiency had only improved marginally,  thus the 13B turbo first came with a topmounted IC, but later better ICs were available so the 13B TT had a FMIC. Lag time is quite small if you use a narrow rev range, maximum 0.1 of a second. An example would be a timed 1/4 mile lauching at 5,000rpm.  The lag is greater for a normal traffic light take-off dropping the clutch at 1,500rpm and revving to 6,000 before changing to second.

Most of my driving is long  distance, 750 miles with 2 traffic lights and a fuel stop so using a narrow rev range I decided on a FMIC. If however, most of my driving was urban, turbo lag would have been more of a concern so I might not have gone IC. My brother bought an Elford new, and  there was no noticeable turbo lag compared with my NA twin Webber Elan. Unfortunately, the Elford was often in the workshop.  

 Sorry for such a long reply, but its an interesting subject. I spend much of my time in remote areas so research my RX -7 as a way of keeping in touch with reality. Just spent 6 months on the China-Afghan border, a little differenf from my earlier life in Somerset!

[Don Pamponi]

I hear what you are saying, I was going to fit an IC but I think the Water Inj works better (although with higher running/maintenance costs).

My only complaint with the car (apart from the rattles that I just cant trace!) is the poor, low geared, wobbly, heavy, vague & generaly SH*TE steering.

If I\'m going to keep this car then I MUST fit rack & pinion steering.

Need new shocks/springs all round too.  Its way too hard with the gas shocks on.

[PaulFitzwarryne]

Fully agree about the steering, very heavy at low speeds but far too light above 60 mph. Mine is tightened up about every six months for slight improvement. Rack and pinion is the solution but no one does a well engineered kit.

Water injection is a good modification.

[Don Pamponi]

I\'m having a rack put in over the winter hopefully.  Maybe powered, maybe it wont need it.  I shall take advice in that.