7 port ignition mapping issue.
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I agree with Dave on the power, I would have thought the "headline" figure is a secondary consideration and the main benefit from 7 port and injection would be general driveability, mid range torque, and that the thing generally behaves itself come wind rain snow or high water.

I'll give him a call, Im just a little disappointed with the bottom performance really, the 5 port matches it until about 4k. I think your right, something mechanic isn't right and I strongly suspect valve height/crush to start with. As I said my main concerns are valve Clearence, lose of power from standard to 1.5 rockers (3bhp) and amount of ignition needed.

Black Line is 18thou valve clearence
Red Line is 15tho.

20 ft/lb difference and 10bhp

Nothing else was changed.

Edited by alaskanow0 on 31st Aug, 2012.

Class C 3rd Place Avon 2011 14.18 @101mph

Here is my ignition map. Please note this map was only mapped for 100% Throttle. So not all values are optimium.

Edited by alaskanow0 on 31st Aug, 2012.

Class C 3rd Place Avon 2011 14.18 @101mph

Class C 3rd Place Avon 2011 14.18 @101mph

al ,is that from a dynocom dyno by any chance ? if so it may be worth considering a different make of rollers and get some other figures to work from .

looking at the map , i see a mass of rpm over 7krpm rows ,you are revving to what looks like 6500rpm ? can those numbers be replaced with a graduation more suited to focussing on the bottom end and helping to map the off cam area.
as has been said , you either have a innacurate spark or a very low cr ,or possibly such a low air speed due to the big ports its not filling the chamber well ,but this seems a remote possibility and would get less problematic as the rpm goes up . another possibilty would be an intake restriction ,but again can't see that from the design you have described .

Edited by robert on 31st Aug, 2012.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

It's not my dyno, but I can't moan as I get to use it for free. The results are always consistent with every run. The results chances were all from the same session.

Class C 3rd Place Avon 2011 14.18 @101mph

fair enough , in that case ,can you get then reprinted with the smoothing set to 1 or 2 to show more detail ? when we did the tm dyno shootout ,the graphs were done on smoothing no 5 ,which hid a lot of info and reduced some power outputs .

oh something else that is probably not applicable and you have it covered ,is , when i printed a graph of my crank power over wheel power it looked just like your red and black lines ,might be worth checking the software hasnt done 'adding losses' on one graph and 'no addition' on the other .

Edited by robert on 31st Aug, 2012.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Inlet pulse issues. Engleman & Helmhotz are the men to talk to.

Big, short inlet runners. high frequency intakes pulses, low volumetric efficiency due to low inlet tract pressure as intake valve closes allowing high ignition advance.

Small change to the inlet valve closing point makes a big difference. Follows theory but a bit extreme.

Solution - long intake runners.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

If you use this cam in an engine that rarely sees over 5k rpm, and are dissapointed with the bottom end power and torque, I suggest you could be using the wrong cam, plain as. Your print out above shows the power still climing at 6.5k rpm, but yes, 42 degrees is a bit much and to be honest should be detonating at that if everyting else is correct.



Swiftunes own words

"A wilder profile than the SW5-07, the SW10 is Swiftune's version of the highly successful MD286, same characteristics, but more efficient on idle to help the MOT emission test. Expect a lumpy engine idle, 'off cam' until 2800/3000rpm with the real power from 5000rpm. Ultimately the SW10 will produce approximately 10bhp more power at full revs."

Also, moving cam timing from 108 to 106, you have advanced the cam, and in doing so, pushed the power band further up the revs, not down. If you wanted to reduce the peak rpm, giving a little more lower down, you would want to retard the cam and you should have gone with 110 degrees, but I'd agree with Paul, Swiftune would not suggest 108 on theiir own cam, if it was better at 106. Why would you listen to people whom had no input into the specific design of the cam, over those people that did infact actually specify and design the profile?

If anything, the engine needs a longer duration cam to match the characteristics of the head and induction system. It would then all come alive above 7k which is what the head is designed for.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

but still be shit low down...

What about MAT retard? what was the intake charge temps like during dyno pulls?

If MAT retard is pulling out 10 degrees because the charge temps are high because it is on the dyno, or the MAT sensor is suffering heat soak, you'll kill the engine on the road for sure.

It could be that the MAT retard is not tuned correctly and artificially removing advance, and making you 'artifically' put it back in in the main ignition table

Edit** The DTA also has coolant temp retard so worth checking the air temp and coolant temp corrections

Edited by Sprocket on 31st Aug, 2012.

Pop a 544 cam in there timed at 110 and then see what happens mat

In fairness, I choose the camshaft on recommendation from Swiftune. Whilst waiting for the 7 port head, I ran with the stage 4 5 Port head. I was very happy with the cam and setup. My disappointment was in no real gain from the 7 port in the mid range. Loads of people run 286 cams on the road and seem happy. I did want the option of occasional 7k pulls, especially with the TB induction noise.

School boy error with regard to cam timing, I thought advance and retard where the other way around

Class C 3rd Place Avon 2011 14.18 @101mph

Air temps are all around 20 degrees, with no correction. But you might be onto something, I'll check all the different correction maps.

Class C 3rd Place Avon 2011 14.18 @101mph

What diff ratio do you run? This can have a big impact on how the cam behaves low down

I seriously doubt it!

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

So advancing the cams means a higher or lower number than recommend.

Final Drive is 3.1, and car is full weight with full extra sound deadening to all floor, Panals, doors etc (+50kg) Subwoofer, amp etc. I know it needs a 3.44 really, and it's on the cards when the engine is next out.

Robert, it's a good point about graph smoothing, next time am there will play with the different setting. I'm confident the change in valve Clearence was accurate, as you could real the extra torque straight away, and it then was able to pull from 2k.

Edited by alaskanow0 on 1st Sep, 2012.

Class C 3rd Place Avon 2011 14.18 @101mph

Advancing and retarding the cam isnt recommended, its a bit daft actually, its designed to do a job at a specific timing so set it as it should be and leave it alone.
The 3.1 is killing it. You have a relatively small cc and cam so the engine will not pick up due to the small amount of torque and power it can produce, you need revs on an n/a - not necessarily high revs - it needs to be able to pick up quickly

I seriously doubt it!

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Just out of interest could you give the intake lenght from valve to intake (so i can run pipemax and see what it spits out? stem size ?)

I don't get why the increase in tappet clearance would have such a large effect. Especially the fact that after gaining midrange it tops out is very odd.

It just should not. Not with this cam and the bulk flow capabilities of this head. less than ideal midrange ok.. but the topend should be somewhere around 7,3-7,5k i'd recon.

people run similar configs with good topend power so while the ports are too big etc etc.. it should still work

do you have standoff problems? weird fueling ?
how much CFM does the head flow at max cam lift ?

Edited by Sir Yun on 1st Sep, 2012.

That sir, is not rust, it is the progressive mass reduction system

http://aseriesmodifications.wordpress.com/

I think its well worth rigging up some long intakes, (think toilet rolls and gaffa tape!) to see what happens.

In the 13's at last!.. Just

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