Thread: Went to the dyno last night, tell me what you think

Stage 4's can make good power based on 140kw at 9000rpm and still climbing i got. But my exhaust is pretty free flowing (not to mention LOUD)

Hybrid cams look promising. Nice dyno runs.

Make everything the same and a a 3 inch Burns style collector.

i wonder what hp power these cars would make on a USA dyno, i think all of the N1 cam cars would be over 200hp

Its not relative because there are many, many people here in the USA with N1s and FS4 cams that got no where close to 200 WHP.

The collector right there where the extractors end? What about a secondry pipe? Would you make it a 4 into 1 collector or 2 Y collectors into 1?
Getting my 20V extractors from the guy I sold the engine to early next week.

I would go short primaries, measure the 20V ones to the collector.

The run a 2 Y collector setup.

Those 20V headers do work very very well. So in my opinion I would try to match them as closely as posible.

As you know the 20V header is a very funny try Y setup.

Ive got the factory secondaries here, been thinking of remaking them up without the cat and trying them, they are around 10 inch's to the cat, which i guess works as the collector.

Ive got my old 20v sec's on the wagon atm with a cat free 2.5 inch pipe, might put the cats back on at some stage, as all cars registered after jan this year need a cat for Warrant of Fitness test. Removing the cat from evlnxr gave it 10kw, but that was making it into a 3" dump pipe off the bottom of the 20v headers, so dont know if it was the cat or the dump pipe that made the extra power.

Ive got the manifold plates and madrel bends to make some headers turning up soon, so will be looking to make them 1 7/8 primaries, and 2 " secondaries, with a 2.5 or 3" collector (im leaning towards the 3" for top end flow)

I measured the 20v headers a while ago, cant remember how long they were, but they were not equal length by any means. I also ported mine to match the port on the head.

Well tuning was interesting tonight, the low lobes make power to 6500 rpm, any earlier and there is a sag.

We are still getting 4.3 volts on the q45 maf, which is similar to the stage 4's, so the engine is still moving similar amounts of air, and hopefully will turn out similar numbers on the dyno.

We had to take out lots of fuel at the switchover point, otherwise it went well into the 11's, then back into way more fuel by 7100 to cope with the extra flow on the high lobes.

Gave it one last run on the way back from tuning road, and threw the alternator belt, 8 km from the garage, at night, with a very small gel cell race battery, volts was down to 10.8 by the time we got back.

It drives very very well, heaps of torque, and has got rid of the flat spot from the cam switch being too low. Added a bit more timing at mid range to give it even more pep, and the knock indicator is not showing any large spikes.

The tuning we did before dyno day is way off now, and the only thing that has changed is fixing a exhaust leak at the bottom of the 20v headers.

Keep it coming.

I know when you are done this cam combo will show what it is made of. You could see by the graph that the switch point was way to low because of the curve down ward. What was happening is the air speed fell of in the intake from early cam change going to the bigger lobe this is what made the car run rich as the ecu did not have enough time to compensate.. All I did was to make a line from your switch point and followed the rainbow curve to the actual switch point thats how I came up with 6400-6600 RPMs.

Using a little speculation and some math goes hand in hand with tuning. I wish I was there I am actually a very good tuner.

I stand behind this cam combo 100%. I also think that there needs to be a little playing around with the actual lobe centers when they grind the cams. Either the 20V bottoms need to be moved over to the N1 lobe centers or the N1s need to be moved over to the 20V lobe centers or maybe find a medium point between the 2 and do that. We will leave that for another disscusion when you are done.

Or we can just move on to the new cam profile I came up with.

Keep up the work I cant wait to see the next dyno with the fixes you made.