Hello all.

I've been sneaking around the forums for quite a while researching as much as possible on the topic of ITB tuning, as well as google, engine books, shop owners, pretty much anyone I can talk to about the topic.

I'm no stranger to tuning, but I have not yet messed with an ITB'd car.. although I have tuned via alpha-n before.

for the biggest shock, I don't even drive a honda. I'm driving a cavalier (weekend driver/racer) with an ecotec engine (yea I know I'll prolly hear tons of crap from you guys) but when the motor was still fresh, I was running consistent 14.0/14.1 @ 96mph all motor on a stock block and trans (ie. no LSD). I had some headwork, really mild cams, and exhaust (nothing spectacular) but after a long decision as whether or not to turbo charge or stay n/a, I'm sort of thirsting for more n/a.

the next logical step would be higher compression (stock is 10:1) and ITBs. I've already stepped to a cobalt SS bottom end with a shorter stroke since it has a much better rod ratio. I've spoken to scott at Kinsler, and we've already started planning out my ITB setup. I've also located a shop near me (M2race systems) that ports ecotec heads to around 290cfm @ .450" lift (the cams I'm using are .457" lift)

but mechanical parts aside, the tuning has me a bit concerned. I'm going to be running a spectre eMS stand alone (based on megasquirt) to run fuel and spark, and I plan on using it in alpha-n mode. I know you guys use Crome, and I've picked up some blended MAP/alpha-n systems in here and i was curious as to the reason for the blended system. I sort of remember mid-range being a problem fuel wise and that being the reason. My EMS has the ability to run a blended speed density/alpha-n system but I'm looking for a bit of elaboration here.

Also, does anyone run a wasted-spark coil ignition all motor, or are you all distributor? I could see getting a MAP signal for the ignition advance being a problem as well.

I have a decent handle on whats needed in order to get the ITBs to run properly, but I'm looking for a bit of advice from those who are experienced in tuning ITBs so I have a bit of a better idea as to what I'm biting into.

And please, easy on the cavalier crap.. I have nothing but the utmost respect for you guys and I'm looking for advice in the all motor area. I've picked up some very informative topics and articles from here and team integra, and I'm hoping this thread will shed some light on my few remaining concerns.

 

I'm not familiar with spectre at all, but, as long as you have total control over accel fueling, you should be fine. If your ITB's are synchronized properly, tuning idle, steady state cruise, and WOT conditions shouldn't be any different. The biggest difference "tuning it" will be in the accel fuel table(s) because you need such a huge shot right off idle, and at part throttle conditions. You're moving a lot more air with a smaller amount of throttle travel.

btw- straying from your ecotec site for the real tech. info. here on the Honda site? lol
Welcome.
scott

 

1 post I do not know if I can PM you. You need a Alpha-N system. Way easier to tune. DTA makes 2. Wasted spark works, coil-on's give more range for more money. 5-8 BHP.

 

the ecotec site is good for general information and basic boost stuff, but I'm breaking into a realm less traveled.. I've even created the first "hybrid" ecotec engine combining an LSJ bottom end (2.0 supercharged) with an L61 head (2.2 n/a head)

the LSJ bottom has a shorter stroke than the L61 (86mm vs 94.3mm) but the same bore size (86mm)... nice and square. Also the rod ratio is around 1.68 which is much better than the 2.2's 1.57 or some crap.. I forget its been a while since I did the calculation.

spectre really is essentially megasquirt. It uses megatune, and it runs the MSnS extra code. The only differences are the box looks different, the board is all-inclusive. It has dipswitches to let you configure ignition and injector settings, as well as lets you use a hall-effect or VR sensor for the crank pickup.

my ignition isn't "true" coil-on-plug, its a wasted spark setup (2 coils.. 1and4 & 2and3) and I'm pretty sure I'm going to need a MAP signal for the EMS to determine my advance

I was hoping just a raw alpha-n system would get the job done. Again, my EMS can run in either pure Alpha-n, Alpha-n/Speed density MIX, or Speed density.

I do not believe MSnS has support for COP.