Here's a plot of my ITS FC RX-7. The car competes in SCCA's Improved Touring S class. Stock port 6-port engine is required per rules. We're using the 9.7 rotors. Stock injection. Basically everything from the AFM to the exhaust port has to be stock to be within the rules. Exhaust mods are free. We use a dual outlet header into a custom (and not quite right) long primary system. We'll be changing exhausts and heading back to the dyno shortly. We made 166 corrected WHP and 128 lb/ft on the Superflow dyno. We settled on 25psi of fuel pressure and the mixture is still a bit fat. The FPR starts to wig out at anything under 25psi so we stopped there and we'll need to figure something out to drop the A/F ratio some more. We played with timing quite a bit and saw nice gains all the way to 30* BTDC leading maximum advance. After that the curve didn't change so we left it there.



Speedsource, THE name in ITS RX-7s which won the Grand-Am ST title last year in their RX-8s, claims 175 WHP from their engine/exhaust package. For building our own motors and exhausts in-house I'd say we're doing pretty well. We're confident the new exhaust and more tuning will put us over the 170 mark and very close to the 175 mark.



http://www.kyrotary.com/rrxp689/RX-7/ITS%20dyno.jpg

your new exh setup will be a shorter primaries collected? expension chambered?

[quote name='GTUs' date='Mar 16 2005, 11:04 PM']your new exh setup will be a shorter primaries collected? expension chambered?


[/quote]





Yes. We're going to try the ISC setup. I also plan on rebuilding the long primary system to the proper specs and testing the two head to head.

[quote name='C. Ludwig' date='Mar 17 2005, 04:59 AM']Yes. We're going to try the ISC setup. I also plan on rebuilding the long primary system to the proper specs and testing the two head to head.


[/quote]





SHORT=24"? LONG=96 TO 102"?

[quote name='GTUs' date='Mar 19 2005, 04:50 AM']SHORT=24"? LONG=96 TO 102"?


[/quote]





Not totally sure what the length on the ISC setup is but it's longer than 24". Would stand to reason it'd be a little longer for the relatively low revving stock port motor. I've seen Speedsource's short system and the ISC system looks to be the same length but ISC incorporates the expansion chamber. Yes the proper long system will be around 8' long, complicated, heavy, etc. I just want to try it to see where we end up. Plus the car is underweight and has to carry ballast plus extra fuel so adding more weight to the underside of the car isn't neccesarily a bad thing.

ISC?

Wow. Back from the dead.



ISC is iscracing.net



As for an update, the car that was originally posted on was sold. We managed to find quite a bit more power out of it with fuel tuning alone and left the exhaust as it was. This spring we built an engine for a racer out of Tennessee and did the tuning work. With his Speedsource exhaust system we found 174 whp.



As a side note we worked quite a bit with DTI on their rtek 2.0 system for the S5 NA. They built the ITS version at our request and it's shown great results on the race cars as well as street cars. We're finding 10+ hp in certain areas of the usable rev range. On a stock S5 street car we picked up an honest 14 hp peak and extended the rev range by about 700 rpm with fuel tuning alone. If anyone is interested in those ECUs feel free to contact me since we're now a vendor for the DTI line.

thats very cool, we spent a lot of time getting the e6x in the stock case, and now you dont have to https://www.nopistons.com/forums/pub...#>/biggrin.gif

Yeah the p-n-p ECU works great for the application. I posted some dyno results and data logs on it.com and rx7club. For the money it's impossible to beat IMO. Looks like the SCCA is going to take the bold step to allow full standalones in IT though. So all the guys that have payed big bucks to have their Motecs cut up and crammed in the stock case will cry. https://www.nopistons.com/forums/pub...IR#>/smile.gif

i know some of the guys around here were using the sds ecus in the stock case with the sds harness, i wonder if thats why the scca said f-it, and said standalones are ok? either that or the 20year old wiring