not making the power

**sprattzvx** · 10-16-2011

hi all.
couple of questions for the gurus if you can be bothered.
i have an l67 that runs a stage 2 intense blower cam and a 25mm composite w2a intercooler setup, along with all the supporting mods like double roller 105 springs etc etc.
firstly, its not really making the power it should be. it drives sweet and idles nice good economy etc, but should be a little quicker. i use tuner pro software and have it dialled in pretty good. running a 79mm pulley im getting 14-15 degrees advance with only occasional knock, which for our aussie blowers with the u bend is pretty good. using 98 octane. a/f at wot is around 11.3.
i have no vac leaks and compression is good. tuning with a wide band.
which brings me to my first question, at wot throttle in first gear its pig rich like 10.3, but when it hits second its nice at 11.3. no amount of fiddling with pe multipliers or injector constants can fix this without upsetting the a/f ratios in the other gears.
im running a surge tank with a bosch 044 stock reg maybe the stock reg is not upto controlling the fuel pressure, but this should happen regardless of gear. is there any where in the tune that might cause this, before i start replacing the fuel system hardware piece by piece?
cheers guys.

**01gpgt01** · 10-16-2011

I know my car when it dips into the high 10's it bogs like crazy from the over fueling let alone a low 10. Also having low Ignition timing on top of that doesn't help. Being intercooled you want to be atleast 11.5-11.9 range IMO. There are table modifiers (rpm Vs time) that id start with. Id Zero those out till 12 sec range then let it add some fuel.

**sprattzvx** · 10-16-2011

Originally Posted by 01gpgt01

I know my car when it dips into the high 10's it bogs like crazy from the over fueling let alone a low 10. Also having low Ignition timing on top of that doesn't help. Being intercooled you want to be atleast 11.5-11.9 range IMO. There are table modifiers (rpm Vs time) that id start with. Id Zero those out till 12 sec range then let it add some fuel.

Ah ok, so 11.5-11.9 is considered safe? Ive been told the power diff between high tens and high elevens is minor, but then others like yourself say power drops sharp if too rich. But yeah it pulls alot better in second with the 11.3. Ive kept it rich for safetys sake buf if its costing me power, then i guess i should man up and lean it out a bit. It was faster with 1.9 rockers then it is now with the s2.
Ive looked at the pe vs rpm.vs time modifier, but never payed it much attention as its already zeroed for the initial 8 seconds, i guess this was done in the original base that was made for me. You guys seem to get alot more timing into your setups then us aussies, even though our fuel is bettet, guess your blowers are more efficient without the ubend to restrict them.

**matt5112** · 10-16-2011

Some like to see 12 when intercooled.

Others like to stay around 11.2

pulley up. should be a minimum of 16* ignition timing.

Then play with the fueling to see the difference.

what is it? Fuel > Timing > Boost?

**sprattzvx** · 10-17-2011

Had a look at pe vs time multplier, and is actually set at 1.0 for the first 8 seconds of pe.
I could use this to correct the first gear fueling from a standing start but will cause a lean out when rolling on in any other gear, not good. I really am confused as to why fueling is different in first even though its fueling from the same mgc/rpm from the injec consant table and using the same modifiers.....surely it has to be a hardware issue doesnt make sense unless there is setting somewhere im missing. Frustrating stuff.
Regarding spark timing, i worked my way up to 15 degrees in the mid range tapering of to around 10 at peak revs. I wasnt getting knock but didnt want to push it. How do you guys generally have your timing curves ie start low build to midrange and taper of in the top? Or more flattish? Once i get the fuel sorted ill start leaning on the advance abit.
Its great getting opinions from you guys as you are a few years ahead in the l67 scene most of our stuff is from the us scene apart from our a2a coolers.

**Z34Phoenix** · 10-17-2011

Ive never heard of the tuner pro software. i was only aware of DHP and HPtuners. Maybe tiny tuners software could help? it gives access to a few more tables not available in other tuners... one idea that popped into my head too was AE but dont think it would cover all of 1st gear though.

You say with Ubend... are you not able to remove it because of regulations? that 79mm comes out to a 3.1" pulley if i calculated it right. that is pretty small for those mods i would think considering on 87.

also when you say "not making the power" are you saying on the dyno, or at the track, or just the butt dyno/ feel of it.

**sprattzvx** · 10-17-2011

Originally Posted by Z34Phoenix

Ive never heard of the tuner pro software. i was only aware of DHP and HPtuners. Maybe tiny tuners software could help? it gives access to a few more tables not available in other tuners... one idea that popped into my head too was AE but dont think it would cover all of 1st gear though.

You say with Ubend... are you not able to remove it because of regulations? that 79mm comes out to a 3.1" pulley if i calculated it right. that is pretty small for those mods i would think considering on 87.

also when you say "not making the power" are you saying on the dyno, or at the track, or just the butt dyno/ feel of it.

Hi phoenix. I run only 98 octane which is available at every fuel station over here. Our l67 cars are all rear wheel drive, and as such with north south config require a u bend to clear the firewall. Also no factory fitted map sensor, maf only. The exhaust (stock) are all twin systems twin cats. I use tuner pro as a custom tune over here cost around 1200 us dollars minimum, so ive chosen to learn to tune myself as im always looking at the next mod. Our ecu is delco, and custom tuners are not readily available. A 79mm pulleys is considered conservative in aus when running a cooler, cam, 4 inch intake and k&n pod, ported blower and lim with a custom tune. Alot of guys are running 64-67 mm pulleys with similiar mods.
Comparing the performance of my car now to others with similiar mods, its very obvious it down on power, ive been told its all in the tune, when i become fluent with tuning it will come together hopefully, persistance is key. Just thougt some of you guys might have handy tuning tips.

**Z34Phoenix** · 10-17-2011

oh my mistake on the fuel. 98 should be great. im just pulling at strings, but with the inter-cooler your running are the gaskets matched properly as to not block it off? and is there porting to the outlet of the blower to match the IC?

i use a program called Eddies table modifier. it makes tuning much easier. because it displays the data from a log to match the spark tables (same format/layout). without seeing the tables you have, i too would say look at PEvsTime but my fear is if your step on it from a roll that it will cause you to be lean. is there away to add timing down there maybe?

**FoSHO99** · 10-17-2011

That IC only comes out to about an inch, which most of ours are 2+. With that said you may want to look at going to a bigger core or look at your air temps post intercooler. What type of throttle body do you have or what size?

Usually I tune them to run in the 11.0-11.5afr range non intercooled on 91octane. Full size intercooler (2"+), you can get a little leaner as the IC does it's job, around 11.7-12.2. Tuning for higher octane usually reduces the chance for detonation so typically you want a 12.XX afr especially when running at the track. Off the track daily driving, you may want to have a different tune in the high 11's if you run 98 all the time.

For timing, i would at least try to get in the 16-18* range and if not possible, pulley up. At the 4,500+rpm range try to keep the timing rising slowly with rpm's.

**Juanmiguel** · 10-18-2011

Maybe it would help if you could post a log from one of your runs. In image format if you don't have a file share account setup. It would be easier to see what your PCM is trying to do.

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