In issue 156 and 157 AutoSpeed did articles on the Ford and Holden V8. After looking at Aaron's Dyno run info, it was interesting to compare some of the comments made and how they might apply to the Soarer V8.
Chip tuning on a 220kW Falcon
Comments on an AutoSpeed article
"Starting peak power: 136kW at the wheels. Peak power after the chip re-write: 144kW. Gain? 6 per cent. Cost? $700."
Compare to Standard SOARER V8 of 130 KW at rear wheels.
The hottest, meanest Falcon you can get has about the same rearwheel horsepower as Aaron’s 10 year old, 140 000 km Soarer with no filter.
"From reading the Autronic/Dyno Dynamics air/fuel ratio meter we already knew the fuelling strategy at full throttle - mega-rich with a ratio of around 10.2:1."
Once again factory rich air/fuel ratios are safe but rob power.
"the mixtures again behaving as they were being directed to - high Elevens (eg 11.8 - 11.9:1) was the aim"
Compare to Aarons fuel mixture ratios of 10.9-11.3 at max power – too rich.
"So, there're two ways of looking at it. (1) Wonders had been done in extracting that much extra power from lower grade fuel - and oh boy, wouldn't the car now be safe when filled with premium! Or (2) how much extra power would have been possible if some more timing had been able to be cranked into it (or, at minimum, not been taken out?). Looking at the figures on the dyno during the timing changes, I'd suggest perhaps only a few kilowatts more would have been achieved. It was the change in mixtures that made the big difference - and they'd be almost completely unaffected by the different fuels."
The Falcon had regular petrol in tank. Again up comes the type of fuel power versus power question. The SOARER V8 does have a knock sensor doesn’t it? – do we only develop full power on 98 RON fuel because the knock sensor instructs the ECU to reduce ignition advance when detonation occurs with crappy low octane fue? Mark Tilbrook said you couldn’t do much with the timing on the ECU (make it more advanced for more power) because it was already set up for Japanese 100 RON fuel – couldn’t advance it much more on Australian 91 Octane (regular unleaded), 96 Octane (premium unleaded), or 98 Octane (BP 98 or Mobil 8000 or Shell Optimax). Any one know for sure?
We tap into the mind of one of Australia's best Holden tuners to give you the ins-and-outs of the local Holden 5.0/5.7 V8...
More comments on AutoSpeed V8 article
"What size airflow meters were used from the VT and Series 3 VS ute onward? Sixty five millimetre - but the HSVs run a 75."
(SOARER runs 3 inch or 76mm I think, have to recheck.)
"HSVs through too - a 5.7-litre VS Senator did 195hp at the wheels (145 kW)"
Aarons standard V8 did 128 kW at wheels.
"Will running a standard Holden V8 on premium unleaded make any difference?
Nah, it doesn't make any difference unless you're talking an HSV that's running a knock sensor. HSVs run a lot of advance in the main timing table and - when it detects knock - they figure it's best to pull a whole heap of timing out to kill detonation. The knock sensor is calibrated from 1800 rpm to 3000 rpm and it can pull 12 degrees off timing. I know a lot of people who've ran their [fuelled on normal unleaded] HSV off the line and they reckon it just goes dead off idle until about 3000. Premium unleaded will get rid of this and people feel there's more power."
Soarer V8 has a knock sensor – anyone know how much difference the RON value makes to power on the SOARER? (yes, now we do know it makes a difference - about 4kW everywhere, check out the Octane ALSC dyno day page)
"Most people put an over-the-radiator style one in there - though you might have problems doing that with the bonnet frame of an early VN. You can fit them, but you've gotta heat up the ends of the snorkel and squish it with the bonnet down - so you would lose a bit of airflow. I like the over-the-radiator ones because there's less chance you'll end up with water in your engine.
It's hard to measure the gain on a dyno - it doesn't work on there. But if you did a G-Tech on a car on the road you'd see an improvement - my guess would be about 5kW (6-7hp) at the flywheel. You really notice it on the open road overtaking, where the car feels a bit crisper and pulls a bit harder. Also, we've played with having an over-the-radiator snorkel as well as an intake underneath on a VS ute - that was an eye opener. It worked well with either one, but it worked even better with both. I didn't think there'd be that much difference but there was."
I’ve seen these type of intakes – they don’t look that flash to me – still worth 5kW. Water in the filter is a problem for sure – that’s why I like the BFI over the SS type – water separates out in first chamber. No gain on a dyno since there is not enough flow. Notice that when they fitted both intakes they got a big improvement, bigger than 5 kW obviously – they must be getting close to BFI territory.
"In the case of the VL and VN Group A, I'd just get rid of the standard filter element and put a K&N in it - that makes a difference. It's a good idea on these cars because the standard filter blocks up really quick; "
Aha! - again a K&N is preferred over the standard filter – but read it again, “the standard filter blocks up really quick”. Yet again a K&N filter is compared to a dirty blocked standard filter- the only time I have seen a K&N compared to a new filter was on a WRX and they couldn't measure a difference. I want my filter to block up, I want it to filter out the dirt, I don’t want to fit a filter that lasts for 50 000 km. If it doesn’t block up where does the dirt go? I replace my standard filter every year to keep it flowing great, leave it too long and it will remove so much dirt that it will get blocked and flow twice as bad as a new one. BMC advertise their filters as being used for Formula 1 – so if you rebuild your engine every 3 hours then BMC have a filter for you. I want my V8 to last 1 million kms. I want to pass it on to my unborn son. NO magic, never get blocked filter for me thanks – I’ll live with the 2kW loss in power.
"Would you recommend a re-map after an exhaust and intake? A re-map might not be absolutely necessary. They run closed-loop in a pretty big area - that should clean up the light load mixtures. Under WOT, you might find the mixtures have become a little bit leaner, which helps power. But - having said that - you can get flat spots. Tuning will definitely get rid of that. A re-map - I'd say - is needed once you put a bigger cam in."
Interesting, closed loop always readjusts to standard air/fuel mixtures – SOARER V8 is very rich too.
"standard intake manifold they're wasting their time. It cannot flow enough air. Like, even with the fairly mild Crane 276 in it, you pull 1-2 inches of manifold vacuum at full noise.
when Holden put the 5.7-litre Harrop crank in, the engine (with the same 5.0-litre intake manifold) pulls 2-3 inches of vacuum at around 4800 or 4900 rpm and full noise. That's in standard form - so it's already saying, hey, the intake manifold is too small. "
After reading this I hooked up the manifold vacuum gauge (I had a couple to tune my old BMW with twin carbs) to the Soarer manifold. Out on the rod full throttle in 2nd gear the biggest vacuum I measured was under 1 inch of mercury - so it looks like the Soarer manifold and throttle body are up to the job.
"Holden 5.0 with 11.5:1 pistons, solid cam - the works, except a standard intake manifold - make 285hp at the back wheels. Keeping the same cam but swapping to a Group A manifold (as well as bigger injectors and a re-map) took it up to 356hp (265KW)"
Okay, so 265 kW at the wheels is plenty. The extra litre capacity is worth horsepower over the Soarer - sure we have multi valves and overhead cams and forged everything but cubic inches still count for a lot. This particular engine sounds like it idled like a pig with such a big cam. Changing cams on the SOARER? - doubt it, Different intake manifold? hmmm - have to be custom - lets see what ours is like first of all.
Awesome Automotive+61 8 8277 3927
Beauty! – another South Australian Crowd – time for a visit.
Well what do you think? - any other comments? email me on pgscott@bigpond.com
