Just looking back through the log 1/4 mile log, your 92 mph suggests that you have about 110-112 rwhp, so not bad considering that you are running a couple of pounds less boost.

Dyno's are all good, but the drag strip never lies.

CAR:1200 ute
MOTOR: A15 (104rwhp @ 4800rpm)
CARB: 32/36 weber
SUPERCHARGER: Toyoya SC14 Rootes Blower, 10psi

GEARBOX:4speed std.
CLUTCH: sunny
DIFF: H165 4.11
EXHAUST:2.5"
WHEEL/TYRE package:front 185/60/14
rear 185/60/14
60foot time: 2.1
1/4mile time:14.72
mph/kph:144 kph

Got down to the drags last weekend

14.7 @ 89mph (144km/h)

2.1 sec 60 ft
a lsd and fatter tyres (185's at the mo)would knock a couple of tenths off of that- I was dropping the clutch at 2800rpm

the horsepower/et calcualtors came up with 89mph for my 104 rwhp, but reconed I should be running 15.2

shows the difference a bit of torque can make

before the blower it ran a 16.9 @ about 75mph, so bang for buck factor is pretty good!

It still whips round to 7k in first & second if you're not quick with the changes, but by third it's starting to labour in the top end.

Still comes up feeling gutless with 2 people on board. curse of the light car.

Here are a couple of things I found interesting & thought I might share:

calculated 'ideal' 10psi power increase

EDIT: 'boosted hp/tq are the modelled values, '10psi' is the actual.

this is what you would get if there were no belt drive losses and no heat losses.


what I got.....

up untill the torque drop off at around 4800rpm, the result is almost identical to the modelled result for 7.5psi. no real change in the torque curve at all. now that is really spinning me out.

there's plenty more ponies in there, it's just a matter of find a way to let em out. If you look at the graph, the peak power is at 4800rpm. that's like a old school v8, not an A series. If I can get the torque curve to mirror the original, that should get me up to at least 110-115 rwhp. then for the water injection.

All dynos are different. I'd hazard a guess that if I went back to hyperdrive I'd pick up 5-10% on their dyno.

Righto. preliminary results are in:

Dyno comparison

When I brought it in it was running very rich (deliberate) and still had the standard ignition total advance, so the timing was retatded back to 0 deg BTDC, to avoid getting too much advance in the top end. It ran 85rwhp as I had tuned it, but on the road felt miles ahead of the 72 rwhp which it ran on a different dyno- so as expected, the dyno numbers don't tell the whole story.

We took some fuel out and welded up the ends of the guide holes for the dizzy weights to prevent them from getting full advance.

turned out to be too much fuel and too much advance change & it pinged and dropped some horses.

took the dizzy apart again and filed some of the weld back out & changed the carby jets again. With a bit more stuffiung around we came back with 103rwhp with a total of 18deg of advance.

But here's the real story- Torque. when you do the re calculation, the flywheel torque comes out at around 210 Nm- considerably more than a SR20DE, more than a 108kW 4agze, and it is equaling a 120kW 4-AG 20V by 2200 rpm!!!

I think there is possibly more grunt to be had with more adjustment of the dizzy curve, to try and hold on to the torque for a bit longer.

One of the interesting things to come out of it was that the carby size is ok for this application. we attached a vac guage to the port in the carby base and didn't see more than 1-2 in/Hg at full throttle. if the carby was genuinely too small there would have been a significant vac signal from the carb.

Anyways, happy for the moment, just need to get it to hold up through the top end & I should see 110-115 rwhp which was the target figure.

Quote:

Going to have to go back on this statement to some degree. I had the ute on a dyno today and the ram-flo air filter was robbing me of about 7%!!!! and richening the mixture 0.5 AFR unit

I'll sort things out with a k&N.

Nope.
You can tell by the inlet manifold.

No air filters=wank.

A couple of percent power gain at huge risk is a silly equation, even if you are racing (unless you have a good sponsor)

Quote:

It must be mate- we don't see you round here unless it is