I am looking for some advice from those who build/use race engines. I currently have a 87 GXL, bone stock. It has about 120,000 miles on the original engine. Miraculously, it has compression numbers around 130 or so properly calibrated for speed and altitude. I would like to pull this engine at some point before it dies and rebuild it before something bad happens and trashes hard to get parts.

I do have a spare, ran when pulled S4 engine with roughly the same miles. I was considering rebuilding it, staying N/A with mods and going stand alone. However, with how hard the s4 parts are becoming to get, I think that I should buy something else like, a six port junk yard Renesis. Hoping to save good working unmodified S4 keg, etc.

I do realize that the lower intake of a Renesis will need either the stock ECU or Haltech. However with tech being what it is today, there might be aftermarket options for upper and lower intakes. Most likely not N/A though.

So, what would you do? Mod the S4 or save it? I know cost will be a big player here. Let's just put the cost issue toward the bottom of the worry pile and start there. Also, it would be nice to track the car at some point but also keeping it street legal. Thanks in advance for your thoughts.

(Just as a side note, I will likely be getting a RX8 six speed to pair with my extra 3.9 rear gear at some point, too.)

 

i'd be really tempted by the Rx8 engine, its like 80more hp. and a lot of work to get it in the car and running.

 

Yeah, it's certainly more likable than a likely noisy as hell partially ported N/A S4 for me, too at that HP. Not sure that I would want much more HP than stock.

There are rear end considerations, too. The 3.9 rear isn't ideal with over 200 HP and the RX8 gear box. The Axles will need upgraded, most likely.

Regardless of ultimate direction with the engine, I will likely pull the spare engine apart, clean everything, pack it up nicely and keep it at least until the original engine gets pulled.

 

Renesis all day for a street driven car. You’ll spend money and time building a loud FC engine that doesn’t make as much power as a stock port Renesis.

Wouldn’t go for a taller rear gear either.