T to RS engine swap

[jackson51]

Advice, please…

what are the main requirements or changes to the engine compartment when adding an RS spec engine to a MFI-T spec car? Certainly appreciate any and all feedback about engine upgrade/swap experience. Just looking for guidance on basic steps and clues to issues which turned bigger than expected or were complete blindsides. Thanks for helping, here are my current questions:

Any changes to the electrical panel relays, fuses, or wiring?
Any component changes to spark box, sensors, oil lines?
Are the T and S/RS engine wiring harnesses the same?
Any ducting changes or upgrades?

Recommended upgrades to T spec components or systems?

[jbell959]

What year T do you have? If it's a 72/73 then there are no changes. Everything was the same for the T, E, S, and RS as far as the external components are concerned.

If you have a 70/71 there are some minor differences in the wiring harness and one difference in the left heat exchanger.

[jackson51]

Thanks!

It’s a 72. So basically, I could just bring the fan, ducts, engine tin, and engine wire harness straight onto the RS spec as needed and be good? Then add an oil cooler and S MFI pump up front.

Anyone have experience with the aftermarket throttle bodies Parts Klassik is selling?

[unclebilly]

You will need more oil cooling. Plan on a Carrera oil cooler in the front fender at least.

Otherwise, this is a direct fit.

[jackson51]

Have acquired most of the oil cooler setup… going to start with the loop type. Thanks for input.

[bkreigsr]

Originally Posted by jackson51

Have acquired most of the oil cooler setup… going to start with the loop type. Thanks for input.

I would give that choice a second look.

[unclebilly]

Originally Posted by jackson51

Have acquired most of the oil cooler setup… going to start with the loop type. Thanks for input.

The trombone was not enough for the hotrod 2.7 RS build I did. I had to supplement with a front cooler from an RX7. You will need more than what you have planned. A Carrera fender mount unit would keep your car looking ‘stock’. Even the early cars had a tube style rad in the front fenders (I have a bent one in my scrap metal pile somewhere). It puzzles me why the early turbos had the trombone cooler (it was woefully inadequate when I had my 76 turbo in LA traffic).

[blucille]

The tube style cooler works very well to keep my hot 2.7, 10.5:1, RS+ spec, twin plug, mfi motor cool. Even on the hottest of rally days with the AC running full blast I rarely see anything above the top of the 180 line on my gauge. But I wouldn’t try it with a trombone cooler.

[jackson51]

OK… appreciate your insights.

Was the RX7 cooler in addition to the trombone? In the fender? Behind front bumper?

[unclebilly]

Originally Posted by jackson51

OK… appreciate your insights.

Was the RX7 cooler in addition to the trombone? In the fender? Behind front bumper?

I spliced into my trombone cooler (it was as easy to keep it as get rid of it). Here is the thread where I show what and how I did and it documents temps.

https://forums.pelicanparts.com/porsche-911-technical-forum/492336-budget-oil-cooling-myth-dispelled.html