Micra good news

CMF_Nissanmania

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Been a bit depressing lately watching all the Micra fans become ex-owners or stripping their beasts of their credentials to be sold piece by piece.....

Well, finally some good news. My Micra NA project was fired into life today for the first time. This culminates over a year of planning and many of the last months with the Micra sitting idle awaiting final fitting.

You can check out the photo album on http://nissanmania.fotopic.net if you haven't followed what's happened so far.

Anyway the little beast fired up pretty much first time and after a little initial tuning and warming up settled down to a very menacing lumpy idle not unlike an 1100cc sports bike. It's redline is limited to 5000rpm for the break-in period of 500k's or so so I won't be able to explore the interesting bit between 5-8000rpm but it looks promising. Interestingly the engine seems to have good torque from 2000-5000rpm and drives very well on the street considering how wild the (ex)Datrats cams are. It has the most wicked induction roar now. Sounds like an animal waiting to be unleashed. Soon, all will be revealed when it gets its first proper run on the dyno in the next few weeks when its new redline will be determined and a more aggressive tune set up. Keep you posted.
 

CMF_Nissanmania

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Its currently still a runabout so kept the aircon for the moment so we (including the dog) can survive a Perth summer in it.

Should be getting its final tune later this week. Very interested to see what sort of top end it will have as it's quite meaty in the mid-range.

The Gripper clutch-pack LSD is very nice. Absolutely hauls through and out of corners. Torque steers only when doing a tight right hander like a U-turn. Caught me by suprise the first time it happened.
 

CMF_Nissanmania

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Thanks guys. A few toys there to play with but the Micra is up there close to the S14 for fun-factor. Got a fairly similar dash yet to be fitted to the Micra. Lost the speedo feed with the LSD so need a speedo plus get to monitor lots of stuff - and track timing/mapping/datalogging is a bonus. Insane overkill but I love it!
 

CMF_Nissanmania

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Using a Motec M48 - only because that's what the tuner is familiar with. My S14 runs Autronic. Both are very good with lots of load points for a good tune It's getting the final tune today so will find out tomorrow what it is capable of.
 

CMF_Nissanmania

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Just picked her up and haven't had a chance to give her a good run yet. Yet to scan dyno sheet - 60hp @ 7500rpm = around 70KW at flywheel. Not earth shattering but good improvement over stock run of 45hp @ 6500rpm.
 

CMF_Nissanmania

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Very perky. Pulls cleanly to redline. HP still climbing so could redline at 8000 but kept it at 7500 to be on the safe side.

The true test will be when I can get it onto a track or competition some time in the new year.

Will get the dyno graph on later tonight.
 

CMF_Nissanmania

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This is it. Sorry - its below.

Observations so far are:
1. Could benefit from redesigned plenum/runners (currently stock) to level out the dip at 6500-7000rpm. Possibly quad throttle bodies is the go?
2. Could benefit from better fuel - fair bit of advance taken out of the timing to avoid detonation and more oxygenated fuel will give a bit bang. Currently on 98 pump fuel as still a road going car.
3. Given the very high lift cams the power curve is very close to stock below 5000rpm.
4. Torgue curve is very flat across the whole rev range - not a bad thing I think.
 

CMF_Polar

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whats your timing at the distributor at the moment, nissan allows 17 degrees on 95 octane fuel, so could go a bit higher on 98 octane 19 degrees perhaps?
 

CMF_fred

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if only there was a cheap direct replacement injector readily available in Australia........ Has anyone got any dimensions for the GTIR throttle bodies.... maybe they could be modded? Or take some 40-45mm carbies from motorcycle world might do?
 

CMF_SSUK

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I'm lost completely here. You have a 1.3 engine, cams, ported head, good exhaust system, Motec and you're making 60bhp@7000rpm at the wheels? Which is roughly 80bhp at the flywheel give or take. 5bhp over stock and 1000rpm higher, torque wise that's worse than standard.

Please can you explain more.
 

CMF_Nissanmania

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There is an extra 15hp atw wheels, given around 35% loss equates to around 25 hp or 18KW at the flywheel.

I suppose this is the limitation of NA - the numbers won't be as impressive as with turbo applications.

 

CMF_fred

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but there is throttle response and immediate go.... corner to corner zip through the gears, you know. In a street car application, all out power ain't everything... considering how much time we actually spend on 100% throttle position, Hay! what am I saying!!!!! wash my mouth!!
 

CMF_Nissanmania

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There's plenty of throttle response and urge on the fly. To me it seems more powerful that the numbers would imply.

Looking forward to getting into a competition soon because that's been the purpose of the excercise - create a zippy go-cart.
 

CMF_SSUK

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I assume your first dyno was on the standard car? which showed 45bhp, which is a loss of 30bhp total, or a collosal 40% loss.

The losses from a K11 gearbox should not be this high, you should be expecting to see maximum 25% loss. Typical power loss from a K11 is around 20bhp total on average.

These figures show that something is not right with your setup, have you checked for accident damage or a sticking caliper which would accentuate high transmission losses and therefore adversely effect your figures? You should be making more power that this, especially with the modifications you have made.

I would do some investigation, as it's typical to make between 75-85bhp at the wheels without internal engine or cam modifications.
 

CMF_Nissanmania

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The actual figure is not that important overall, as 2 dyno's can produce different readouts depending on their type and calibration. There's nothing wrong with the brakes and the gearbox is totally rebuilt and in mint condition. The first reading was in stock condition and with the car running sweet. What's important is the comparison between the two graphs. And what it does on the road.
 
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