My B18B1 (on a Type R chasis) was dynoed @ 403hp/291lb-tq with 19psi of boost using C16 race fuel. My question is, if I want to lower the boost lets say to 9psi to use regular fuel or 99 octane, do I just lower it or are there things that I have to keep in mind? At the moment, low boost is set @ 15psi. In other words, if I lower that to 9 or 8 psi, what type of fuel will I be able to use?

I don't know if that will help or not, but pump gas here is 89.5 octane. I know that sucks, go figure we produce it and they can't offer us good fuel! 99 octane, I have to buy, but that's not a problem.

I want to be able to drive my car more on a regular basis (I don't really do that now), but when I need to go high boost (19psi) I will use C16.

BTW, the engine has the following upgrades:
Internal Modifications: Port & Polish & Camber work, Darton sleeves, Stainless-steel O-rings, Crower Rods, JE 9.5:1 pistons and pins, polished OEM Honda crank, ARP studs
External Modifications: XS-Engineering T3/TO4E turbo, Greddy intercooler, Turbonetics Deltagate Mark II, A'PEXi Twin Chamber blow-off valve, 2 ¼” intercooler piping, STR intake manifold ported to match head, JG Engine Dynamics 60mm throttle body, AEM fuel rail, AEM regulator, AEM fuel filter, Thermal R&D Turbo exhaust system, custom 3" downpipe, Turbonetics exhaust manifold, Moroso dry sump oil tank, Fluidyne radiator, FAL twin electrical fan, Mugen 160 thermostat, Integra Type R oil pump, Endyn oil breather tank w/ return, -4 AN oil feed and -10 AN oil return
Engine Management Mods: F.A.S.T. Sequential engine management system (programmed by TDI), 3-bar MAP sensor, Wide band O2 sensor, 720cc/min RC Engineering injectors, Holley 255lph fuel pump, MSD SCI box and distributor cap, MSD HVC coil, A’PEXi AVC-R, Magnecore ignition wires, NGK V-Power spark plugs
Drivetrain Modifications: Clutch Masters Stage 4 clutch, KAAZ limited slip differential, resurfaced flywheel, and a Drife Shaft Stage 3 axles\

Thank you

 

Basically you just lower it like you said. Run around 8 psi or so. You'll run rich as hell unless the F.A.S.T has a multi map optoin. I don't know a thing about that computer. If it does then just tune one map for pump one for race.

 

So if it does have a multi map option, will it make the necessary adjustments when I lower the boost?

When it is tuned for pump (since my race map is working), what is that I have to do? Fuel, timing, etc.

 

Yes you can do it with FAST. It reads the map sensor, so there's different levels for map x rpm. 9-8 psi should be around the 158-177 range of the map (kPa) and just street tune on that level. Once you switch to hight boost which is 19 psi, the map (kPa) should jump on 236 area of the grid and it should be already tuned on that level. Are you following any of these?

 

So when I lower the boost using the AVC-R to 8-9psi, I should be looking at the map and street tune in the range of 158-177 kPa in my laptop, right? That's the part where I don't really get. If you could explain, it would be great.

So do I just go to the gas station, fill it up, and then start street tuning it? What should I keep in mind if I have to use 89 octane, or I can't use it?

Thank you.


Modified by 400_2roll at 5:53 PM 12/14/2003

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 400_2roll &raquo;</TD></TR><TR><TD CLASS="quote">So when I lower the boost using the AVC-R to 8-9psi, I should be looking at the map and street tune in the range of 158-177 kPa in my laptop, right? That's the part where I don't really get. If you could explain, it would be great.

So do I just go to the gas station, fill it up, and then start street tuning it? What should I keep in mind if I have to use 89 octane, or I can't use it?

Thank you.


Modified by 400_2roll at 5:53 PM 12/14/2003</TD></TR></TABLE>

On the Base VE table, it should read in Map (kPa) on the left hand and RPM on the bottom. that tells you what boost level and rpm you are in. Below 100 kPa is vacuum, above that is boost. Just datalog your 8-9 psi and see where it falls on the grid and tune in that area. I cant really tell you how much timing or fuel to add/subtract because every motor is different. i would suggest to just aim for the target a/f and set the timing around 20'ish just to be on the safe side.

 

Right now timing is set @ 25 for high boost; it is the same thing around the 158-177 kPa and RPM grid area. Same thing goes for the Target A/F; it is set at 12.5 for high boost and around the area (158-177 kPa) where it is suppose to be if I lower the boost. As for the Base VE table, it is set between 62 and 77 in the areas for high boost and the tageted low boost.

Thanx TurboDANDEE for your help.

If anyone else has something to add, please feel free!

 

170 kPa should be around 10 psi, according to my calculations. 100 kPa is threshold between boost and vacuum, 200 kPa is 14.5 psi, 300 kPa is around 30 psi. Thats a little chart that could help you figuring out what area you are in.

12.5 a/f with 25 timing @ 19 psi sounds good with C16, but i wouldn't run it that high with pumped gas. i would shoot for 11.5-11.9 a/f and back down the timing also. Hope that helps man, peace!

 

I know I've been asking one question after the other, but I'm trying to learn and figure things out (so please bare with me!). How much should I retard timing, in your opinion, to compensate for using 89 octane fuel? What about spark plugs?

Thanx a lot! You are the man!

 

Set your closed loop O2 feedback on and go to your target a/f table and shoot for a 11.5 a/f ratio in the boost cells. Then go to your Base VE table and adjust the values until your O2 correction factor is within 5%. You would rather it be a little on the rich side and have the ecu take out fuel rather than it running on the lean side and have it had fuel. For 89 octane, 20 degrees total timing sounds about right. A 7 series plug will work fine for 10psi with your turbo.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boostaholic &raquo;</TD></TR><TR><TD CLASS="quote">Then go to your Base VE table and adjust the values until your O2 correction factor is within 5%. You would rather it be a little on the rich side and have the ecu take out fuel rather than it running on the lean side and have it had fuel. </TD></TR></TABLE>

When you say that, should I just use the "Percentage Trim" option in the Edit menu, and just enter 5% for the value, while the values that need to be changed are highlighted?


Modified by 400_2roll at 12:53 PM 12/15/2003

 

One more question about tuning.

Right now I have a KAAZ 4.10 final drive. I had it for top speed reasons. It did help; I reached 265 km/h (approx. 165 mph) & then slowed down. It was good only for top speed, however, I think I would prefer to get shorter gear ranges.

Anyway, I just got an OEM final drive (4.266, right?) last night, as part of this change of plan in my car. My concern is, if I change it will I have any issues with tuning?


Modified by 400_2roll at 11:22 AM 12/22/2003

 

Gearing has nothing to do with engine(fuel/timing) tuning. Gear does effect torque/thrust output in each gear though. A shorter gearing tranny with put more effective thrust too the wheels. Thus acclerating the car faster. If we assume you are keeping traction. So they will help with your acceleration. But if you plan on running slick you will also want to factor those into your equation for final gearing.

 

I changed the timing and a/f ratio and the car ran okay. It was slightly rich but that's fixable. My laptop battery died so I couldn't record the run. But I'll get on that tommorow. Overall, it was really good. It's the first time I fill it up with unleaded fuel. I only used C12 and C16. Now I'm using our crapy fuel of 89 octane. But at least I could drive the car with pump gas!

Thanx guys!