1985 Series 3 restomod with s5 13BT on LPG, R&P steering

[KYPREO]

Thanks mate. A 12A can really sing with just the following mods:
- carby converted to mechanical secondaries and remove all the unnecessary emissions gear
- cold air intake from snorkel to side radiator panel and K&N filter
- decent extractors into a single 2.25" straight through exhaust. (don't bother with the long primaries with a stock port engine - it will work better with a straight single pipe).

The series 3 12A had quite tall primary ports and can make a surprising amount of power once you just let it breathe a little better.

With just the exhaust and intake, my power went from 113hp at the engine to 119rwhp at 7800rpm - roughly a 25% increase, assuming around 20% driveline power losses. Once I modified the carby as well, it definitely revved a lot harder, but I never got to dyno it before the water seals failed.

[spirit r]

- decent extractors into a single 2.25" straight through exhaust. (don't bother with the long primaries with a stock port engine - it will work better with a straight single pipe).

With just the exhaust and intake, my power went from 113hp at the engine to 119rwhp at 7800rpm - roughly a 25% increase, assuming around 20% driveline power losses. Once I modified the carby as well, it definitely revved a lot harder, but I never got to dyno it before the water seals failed.

With just the racing beat long primaries and moded intake manifold my S3 went from 113HP at the engine to 134 rwhp so i am not with you the long primaries with a stock port engine does not work any good. As i changed to a bridge port inlet the exhaustsystem work well since over 20 years now. In my eyes the best alround System you can get for your Money especially you are planing some porting.
see also the racing beat explanation :
http://www.racingbeat.com/RX7-1975-1985 ... 16422.html
The Long Primary system typically adds 5% or more horsepower over a standard Short Primary system on a street ported engine, especially at higher RPMs. This system can also be used on non-ported engines with good results.

[KYPREO]

I didn't say a long primary isn't any good. It's just not as good as a short primary system on a stock port engine. This is based on my back to back experience.

I picked up an amazing long primary system - far superior to the RB one - from a car that set the lap record at our local track here. It was hand built by Rohan Ambrose / Xtreme Rotaries (look him up) and helped his 13B bridgeport make 313 rwhp, which was pretty amazing for 10 years ago. It is a full straight through stainless steel system with tuned length extractors into primaries with straight through resonator on each.

I used this on my 4 port 13B running N/A and it actually made less power (110rwhp) than the stock port series 3 12A with the short primary straight through system. Same car, same driveline, same ignition, same carby (but retuned for the 13B), same tuner.

The 13B has torquier mid-range but is definitely slower. The long primary system was also much much louder and I ended up needing to put a restrictor in one of the tailpipes, costing power even further. I have been informed by local workshops here of similar observations.

Even Racing Beat says the long primary is good for 5% increase on a streetport engine, but only say that it works well on a stock port engine (ie not any better). RB make short primary systems specifically recommended for stock port engines, eg: http://www.racingbeat.com/RX7-1975-1985 ... 16417.html

[KYPREO]

Interested in any thoughts on whether I should:

Option (1) Retain my rear spoiler
Option (2) Factory black rubber spoiler, which is how the car came in the UK and on the very few Australian-delivered Sports variants.
Option (3) No spoiler, which is how the car came on Australian-delivered Limited and Deluxe variants.

If you can't already tell, my vision is for a completely factory restored sleeper inside and out, but making the car everything I've ever wanted it to be mechanically.

The main exception to the appearance is the wheels and the lowering. Wheels is something I've tossed and turned about, but ultimately I'm sticking with aftermarket due to (a) crap tyre choice in 14"; and (b) can't fit decent sized brakes in there.

The only other visually non-standard aspect of the car is the spoiler. Now I've never figured out the precise origin of it, but it has been on the car since at least the mid-1990s or maybe earlier. I reckon it suits the car better than pretty much any aftermarket spoiler I've seen (other than the 80s style race ones) and makes the car very different from other 1st gens out there, but it's not particularly period-correct. It also deletes the factory power antenna and would look weird if I decide to put on the pin stripes around the back and down the side like most dealers put on series 3s (seriously contemplating this).

On the other hand, it would just feel wrong to take it off the car now that it has been on there for most likely over 20 years. It's part of the car's history.

Thoughts?

Option 1 (pics of my car as is)




Option 2



(DKWW2000's car!)

Option 3

[spirit r]

Option 4
Elford rear spoiler

[KYPREO]

Like this one?



Where may I find such a unicorn?!

There is a similar kind of mini-whale tail made by a fibreglass place locally - like a mini version of the Group C kit used in our Bathurst race cars:

[codge]

Option 1.
Deep down I don't believe in making serious cosmetic changes to what are now classic cars of the future......
but your car looks just SUPERB. Leave it as it is.

[A7RXY]

I'm with Dave, codge, option 1 not only does it already look great but if it's not broken why change it .....
Dibs

[DeanRX7]

I like your spoiler but my preference is no spoiler. Especially when lowered, the lines on the car are cleaner and slick with no distraction on the back. Oh and your colour, car, mods and style are very close to what I would say is the perfect 7!

[KYPREO]

Wow thanks for the kind words fellas. Deep down I'm a purist and no spoiler is probably the right thing to do. But it also seems so wrong. I'm completely torn!

And Dean i agree. Tender Blue with grey interior is my favourite combo. 2nd favourite is the optional 2 tone charcoal/silver we got here with red interior.