Im getting ready to spend about 2 days on the dyno to see if I can come up with the perfect tune for my car. I will be running 11 heat range race plugs and 102 octane gas. My goal is to run 15.5~16.5 psi on the stock twins (I know, upper limit of stocks). As I am at the limit of the boost I can get, I will need to adv timing to get the most hp for my application.

In doing my research I can't find any info on what is the "Ideal" adv for a rotary. I know that a piston engine is around ~15 if everything else is perfect. Is there a magic number for the rotary?

Thanks
Dan

 

dan its pretty hard to find on here. nobody really wants to "let the cat out of the bag" so to say. if you want, you can take a look at my map (tuned by BDC). i take it you have datalogit? just let me know if you want to.

oh, and im guessing youll be doing this at performance garage? thats right down the road from me (work and home). im gonna shoot you a pm with my phone number in it. . .

paul

 

That is my shop, Jerry (VetteSport) Chris (Performance Garage) and me (Tweakit Racing) had the building built about almost 4 years ago, 12 bays, 6000 sq ft. If you have ever been in there you have seen my 7 and "Captian America" C4 Corvette and maybe even my SA Rally car .

 

In the single turbo section there is a tuning thread. I believe it has some thoughts from Rice Racing, Kan and others. You could also look at Westbrook's maps, I believe he ran up to 15 psi.

I also dynoed at 15psi with the stock twins. At that time I think I was running a 12 split. My log recorded 13 degress for IGL at n13 or 5,200 rpms. That rpm range is very close to peak torque for a stock port motor.

 

i run 14 degrees igl and 8 igt on pump at one bar.

i log egts digitally on both rotors so i know what works for me and what doesn't. i add 2 degrees past peak torque near redline.

running racegas is a whole nuther thing and i defer to those w experience however i would assume you'd add around 3 degrees advance. obviously my caveat that if you follow my advice and blow your motor into it's 8 major pieces please don't send me the bill.

i notice you are running the Jacobs Pro Street.... it is a serious amp. do you have the "Full Throttle Pedal Switch?" i also wonder about running 10 inch tires upfront. what's the offset and don't you get alot of scrub? 'sure like your swaybar setup.

good luck on the dyno,

howard coleman

 

Howard,

I believe I noticed you may have been running water injection, without wi, what are your peak EGTs?

thanks

 

Thanks for the input. I've already built a spare motor incase something goes wrong .

The pro street I have is pre "Full Throttle switch" I bought it 4 to 5 years ago when RP was selling them. I think its "Full Throttle" all the time the way it eats spark plugs .

Been so long since I bought the CCW's that I have no idea what the offset is anymore, come to think of it I don't think I ever knew. I figured out what I needed the backspace to be and had John make them to spec. I don't have a problem with scrub, but I did have to roll my front fenders. I'm Goint to try and sqeeze 295's on the rear this year for the extra foot print. Depending on how well she puts power down I may even go to 315's. The 295's will add about a 1/2 inch of rake, which is really something I don't need and rake is a pain to adjust out.

Take Care,
Dan

 

Thanks, I have Chuck's maps and have already adjusted them some to suit my car. I'll check out the thread in the single turbo section.

Thanks
Dan

 

i would think 10 inch front tires would cause a scrub radius problem. perhaps in solo (v road racing) where you are doing alot of slower turns the wider track offsets positively the scrub radius disadvantage.. more rear rubber should always help the fd.

i bought the Rotary Pro Pak from RP in May of 03. while they made no mention about the full throttle switch the two wires (red and black in a black sheath w red connectors) were on the box. i recently discovered that the Rotary Pro Pak is identical to the Jacobs Pro Street amp which does feature the full throttle switch. there is a jacobs full throttle switch currently for sale. i do suggest you check your box for the aforementioned wires and if you find them check w either RP or Dennis Mcgee, Jacobs tech/repair guy at 775 882 6600 X346. he is away until march 7.

i recently sold my Rotary Pro Pak and purchased two Jacobs FC3000. i will run one, along w the awesome MSD 8253 coil on each leading plug. the FC3000 has the highest output in terms of volts to coil and current flow mJ of any amp in the CD 6 category. your amp has the exact same guts and output but there is the consideration of the switch.... the FC3000, BTW, eliminates the switch and has a circuit that senses accelerating RPMs and goes full output.

good luck,

howard coleman

 

yeah, i knew you had SOMETHING to do with it. i havent been in there, yet. . . i need to be. . . i need to do some top end runs on the dyno.

 

I would agree, but with my backspace, I don't believe the center of the contact patch has change much if any, even though I have gained width. Is an interesting point I will have to look into more and do a little measuring against stock. My fear with the 295's is that the gain in rake will offset the contact patch gain thus canceling each other out.

Sounds like a nice setup. I'll have to poke around on my Jacob's and see if I have the small black and red wires.

As aways Howard, you have been more than helpful. Thanks for the input.

Dan