I have stock 550 primary and 750 secondary’s I run at a rate of 12.9 to 13.4:1 ratio WOT from 5500 to 8700 RPM NA street port engine. MS1 V3 with pull up resistors. Missing 2 teeth on bottom gear set up. Both sets of injectors are on after 3800RPM with a max duty cycle of 73% at full rpm (8700) on my last dyno run with a ported S4 intake system I pulled 196RWHP at 8700RPM at the end of my last season.

I have now changed over to a ported S5 intake to see if there is an improvement in HP. In my fuel map from last year to this year I had to increase my maxim numbers in all areas of acceleration. Have a look at the attachments old 2010 and new 2011 plus fuel settings.

On the race track it pulls strong may be better than last year (Could be in my head). Lap times are the same as last year but I am running on the same tires as last year which I feel are not gripping as good as last year plus track temperatures were cold (new tires come this week).

I know that as I increase fuel and it burns at the same AFR I must be flowing more air and should be getting more HP. I do not have the brains to work out the numbers. Rather than going to a dyno can one of you mad scientist out there tell me what my HP out put would be now based on the extra fuel being added to the fuel bins in the MS?

Note the air temperature at the track (15 Celsius) was cooler by 10 degrees Celsius compares to when the old 2010 map was made. Same track so elevation will be the same.
Thanks
SCCA RX7 RACER

 

Hey I have formulas and I use them for my own stuff. Working off the 'injected fuel' and the mixture stoichiometry I will guesstimate changes for my own setup. Basically for a constant mixture I assume near on linearity.

That means change from 90% VE @ 7000 to 110% VE @ 7000 = 22% more power. I'm not a believer of that from 'just' an intake manifold, no offence.

Plenty of things could have changed from air leaks in exhaust manifold, blocked injectors, ecu problems. Change in the composition of petrol etc.

If it feels strong be happy but yeah. I have the policy of tuning for survival and being happy that it makes more power (hopefully usable) as I spend more time and money on it

I was happy I was at 109mph terminal speed down the quarter mile. I stripped some weight at went out and did 112mph. I went out tuning with my mate and we put timing in and tested it. I broke my gearbox and have not been back since. Speed traps are the best indication.