RX7 Extra large street port project.
 

I'm getting close to get into the final stage to complete my n/a project and just want to share it to my fellow RX7 members. Engine has been modified with large street port, six port sleeves taken out and connect it as one whole. Today the car finally got into the dyno machine through Gintani and Turbo Joe Tuned. It was pleasure to have a tuner that won't bite your arms and legs even though he helped me out with the initial tuning issues after the rebuild which it was a PITA. Customer satisfaction was his goal, not about the bragging rights! Bolt on and electronic upgrades are RB headers, custom single exhaust and Haltech P1000

Any way here is a copy of the dyno chart and using dyno dynamic machine is a bit conservative number which I'm happy with rather spitting higher numbers.

http://img853.imageshack.us/img853/8727/rx7.png

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Next is paint job, roll cage and turbo.

Here's a picture of the car on the dyno.

http://img528.imageshack.us/img528/6297/photolp.jpg

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Can you post a picture of your port job? I'm confused on how they are now "whole".
Thanks.

I didn't had a chance to take some pictures when I was rebuilding the engine. There are couple of port on the plate one for the regular port and the other half is for the six port. By removing the sleeve's and grinding out the boundaries between the ports will create a one huge whole. This is similar to the four port with the exemption of the larger port on the lower intake manifold and timing. Had the car running at 26 degrees advance and idle at 1200 rpm. Anything lower than 1100 rpm idle will sound like a bridge port with a lot of vibration. I even had the car run at 55 degrees advance once seems to have more torque but will require more fuel and probably higher octane on a hot day.

So you converted your 6 port engine to a 4 port engine???

Like this, but without the bridge?

Yes sir! Just doesn't have the bridge..:nod:

Why didnt u just go with fd or cosmo irons?????

We've made very similar peak numbers on a DD with a street port on the primaries only, secondaries left untouched and only a few peak horse down with completely stock ports. Our combination also netted better power below 7500 than what you're showing. Looks like the only place your monster port is showing any advantage is over 7500. My feeling after seeing the intro to this thread was that you've gone way too big on the secondary port, which has been the observation of everyone that has done this without the supporting modifications to support sustained operation at 9k+. Just needed to pull out the dyno chart to confirm.

https://img442.imageshack.us/img442/7945/dyno2s.jpg

^^ Chad, is that tuned on a Haltech? What series manifold? Those ITS guys came make power on stock ports!

A good street port that isn't gigantic can be made to top 200 rwhp. Those ultra large mega ports just don't work out very well. Yes it makes more power than stock but less than it should. No street ported engine should have to idle at 1100 rpm to be smooth. I've been saying no to this and aux bridge porting for years yet here's another one. :rolleyes:

Well actually, we have tried to rev it to 9000k rpm and it actually made more power. I just decided to have soft rev limit at 8000 since my internals are not balanced. Maybe on my next build I'll have it balance and shoot for 10k rpm. This was just an experiment on my part and it will get boosted some time next year.

I was just working on a blown engine and cannibalize it to build this one.:)