The POS makes it's presents felt...

Show off your Megajolt installations, vehicles and action shots here!

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Humpty
Posts: 55
Joined: Wed Sep 16, 2009 9:09 am
Location: Fremantle, Western Australia
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Post by Humpty »

Been asking around on Shoptalk about all this, as there a few peeps running this stuff on VW's over there..... And things have been pretty active in the chat.... But no real help.... Until Knastenrad chimed in....

He has steered me right and informed me that my map was way off.... It's kinda funny how it happened as I had just read a thread on another forum that confirm for me what Knastenrad suggested....

And this is the fruit of it....

Image

Any better?

Humpty
Posts: 55
Joined: Wed Sep 16, 2009 9:09 am
Location: Fremantle, Western Australia
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Post by Humpty »

Changed the map even more last night....

Image

And took the ol'girl out for a spin.... Even got some dataloging done for the first time.... I must say I'm mighty impressed with it all....
Anybody have a clue how to calculate kpa to psi?.... I'm sure I read it somewhere, but I can't find it now.... My datalog from last night saw 148kpa.... That's 21psi!!!!..... That can't be right?:?:

Fitted the new 'e' tubes this morning and dropped the main jets down to 170's.... Made a huge difference!.... Much cleaner in progression, no more 'fuel' smell in the cabin and no more smokin' (from the tailpipe) when the hammer drops.... Seems to be running cooler too.... It's 30º out right now and I just got back from a long drive.... Cool as.... The manifold is running too cool actually.... Condensation on the carb and intake!!!!..... It's pulls very strongly and seems quite happy.... The 'hunting' I was experiencing at 2800-3000rpm is all but gone and it pulls very clean from there.... But there still is some problems.... The idle is a little erratic... And the fuel pressure fluctuates from 1.5psi to 4psi????.... Fuel pump rpm fluctuates also????.... Gonna fit the LC-1 in the next few days, then I'll figure out how to hook the MJLJ up to the LC-1, then I can get a good look at my jetting and mixtures....

Man what a learning curve!!!

cng1
Posts: 282
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Post by cng1 »

When we talk about "psi of boost" we generally talk in relative terms. What I mean by that is the air around us is at a pressure of 14.7psi, so when we say we have 10 psi of boost that is 10psi on top of the 14.7psi of pressure from the atmostphere so in reality we should be talking about 24.7psi there. Conversely when the engine is sucking against a closed throttle and is pulling 5 psi of vacuum that is actually 5psi from the atmospheric 14.7psi, so the engine is actually seeing an absolute pressure of 9.7psi.

When we work in KPa things are somewhat simpler as we generally always talk in absolute numbers rather than relative ones. 100kpa is atmospheric pressure, so when you are sucking against a closed throttle that goes down to say 50kpa and when you add some boost, as you have done here, your 148kpa is 48KPa above atmospheric. That 48Kpa equates to roughly 7psi of "boost".
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Humpty
Posts: 55
Joined: Wed Sep 16, 2009 9:09 am
Location: Fremantle, Western Australia
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Post by Humpty »

Time for a little update....

After many months of trouble free motoring, the free world came to an end for the POS.... The law got hold of me and band the car from the road.... :cry: They just don't seem to have a sense of humor.... Can't understand why they think a turbo on an old bug running drum brakes, narrowed beam and light weight race wheels (ERCO's) should constitute a hazard to safety on public roads?

:roll:

So anyway.... To cut a very long story short, the car was pulled from the road (until I have been permitted to re-register it.... Which is on the cards), and has now been relegated to drag use for the foreseeable future....

And this is where the fun starts.....

After many months of the poor old POS just sitting idle in the shed, I decided to get the beast going as track star for a while..... Many problems later, I seem to have the car going ok, but constant fuel pressure and volume control has plagued the cars performance...

So my question for you guru's is this....

Is it possible to fit a pressure sensor of some type, that would be compatible with MJLJ?..... I'd really like to data log the fuel systems 'goings on'.....

cng1
Posts: 282
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Post by cng1 »

You can get some VDO pressure gauges which present a 0-5V output which you could connect to the aux input on
the Megajolt.
Official Megajolt distributor for UK and Europe.
Complete Megajolt packages, EDIS kits, Trigger wheels and everything else you need for your megajolt install
www.trigger-wheels.com

Broke4speed
Posts: 100
Joined: Mon Mar 30, 2009 4:49 pm

Post by Broke4speed »

I love it :D.

I'm very close to converting my car to draw-through and would love to know what e-tubes you're using. I've got a set of non-emissions Dells crying out for boost :D.

Humpty
Posts: 55
Joined: Wed Sep 16, 2009 9:09 am
Location: Fremantle, Western Australia
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Post by Humpty »

Glad you like..... I get an absolute blast every time I drive.... Hoping to have it 'back on the road' next week sometime.... Maybe a Christmas prezzy for myself!!!!

Anyway.... I got some tapered E tubes off a dude on theSamba.... Dunno if he's still about.... Shoptalk Forums might also be another good source....

Broke4speed
Posts: 100
Joined: Mon Mar 30, 2009 4:49 pm

Post by Broke4speed »

I'm reading shoptalk right now, lol. I really need to get that turbomania book, and I'm sure I've got the specs for those tapered tubes around here somewhere. Might be time to experiment :D.

Humpty
Posts: 55
Joined: Wed Sep 16, 2009 9:09 am
Location: Fremantle, Western Australia
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Post by Humpty »

Wow its been quiet around here!....

Thought I'd spice things up a bit....

Got some problems with the POS....

Wont pull over 3000rpm.... Can't figure it out.... :?: :?: :?:

Had a fuel issue there for a bit.... Too much pressure at idle.... As the engine is boost referenced I thought possibly the excess fuel was killing the spark.... Seem to have the fuel under control after a complete redo of the entire fuel system....

Still go the problem... In the shed under no load what so ever, the engine will pull above 3k.... But not out in the street....

Wondering if it might be ignition related....

Any of you guru's care to hypothesize?

Humpty
Posts: 55
Joined: Wed Sep 16, 2009 9:09 am
Location: Fremantle, Western Australia
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Post by Humpty »

Work began back on the car in the recent weeks.... Still chasing an illusive general running issue with the car....
Suspected ignition and fuel related problems, so have been working through them....

Fuel was sorted by laying the Holley (x4) and Malpassi FPR's on the alter to the gods of speed.... Fitted an Aeromotive FPR in it's place.... Now my fuel pressure and flow problems are under control...

Still not starting or idling as sweetly as it used to... Obviously I have some jetting work to sort through, but at least the FPR as fixed the control issues....

Then I noticed a few minor issues with the timing sensor and the 36-1 wheel.... The sensor didn't seem to be lining up correctly... And I noticed the timing wheel was running out.... Made some mods to fix them.... Which include moving both the sensor and the wheel 10mm away from the BERG pulley. Also re-routed the sheilding signal wiring from the sensor away from the plug leads...

On the the first try, the car started real nice and idled a treat.... So I loaded the car on the trailer, and headed for the drag strip for a little shakedown time..

Got it to the track and it started to run poorly again.... Draw-through turbo engines don't seem to like idling much (idle jets too rich).... The POS is killing spark plugs... Changed them out.... Right on start up the car ran very nicely.... Took it for a blat....

Got held up at the staging as a car from the previous run had a failure..... The POS began run rough from idling too long..... Gave it a lung full... Cleaned it out.... Staged against a mate with an IDA fed 2276 powered Oval Bug.... Tore out of the gate (easy 4000rpm launch).... Had him for the first 100 or so, then my car began to stall at higher rpm (5K+), just as boost began to rise.... The Oval flew past me and posted an awesome 13.5.... Me.... 15.9.... Shocking I know, but the car feels so much more responsive and has oodles of low down grunt....

So I had a theory.... I reckon the POS is running out of fuel as boost builds.... Noticed the O2 gauge reading very lean at the moment of stalling.... I figured that if I ran a larger main, the car should stall sooner.... Back in the pit I fit a full step larger main to test my theory.... It worked... The car ran nicely once more out of the gate, but broke down earlier.... I reckon the float bowl is being sucked dry by the turbo.... I need to run the FPR with boost referencing connected to sort this issue.... I reckon that's the fix for this issue.... Everything else went very well.... My shakedown passes are finally telling me I'm heading in the right direction.... Car launches well, goes straight.

So that's next, set the O2 to data log with my ignition, do a little more jetting work, then its back to the track.

Humpty
Posts: 55
Joined: Wed Sep 16, 2009 9:09 am
Location: Fremantle, Western Australia
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Post by Humpty »

Got back into the car these past weeks.... Have made many changes.... To many to list here.... But for those that might be interested the whole saga has been posted on my forum.... http://www.noh2o.org/viewtopic.php?t=28 ... &start=525

The DCOE has made way for a Holley 500 2bl...

Image

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And a rejigged fuel system....

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So as of today....

Tried to start the POS.... After fighting a few minor issues with the new fuel fittings and lines.... All my mistakes and nothing to do with the parts....

Then tried to fire her up only to find I have a broken wire to the main ignition power.... Fixed that.... Turned her over..... Nothing.

No map signals on the PC (Megajolt) at all as I turn the engine over....

Guess this is what happens when you leave a tuned car laying around for 6 months!.... Wont even fire on limp home mode.

Tested what I could without an extra pair of hands.... Can't find fault.

So I pulling the MJLJ and engine bay harness out of the car.... Stripped all the wrapping off the wires and have started on testing the wires.... Any suggestions for you Megajolt guru's would be mighty helpful.... Might redo some of the harness to make it ezr to pull from the car in the future.... Once that is done I'll reconnect it all up on a bench next to the car and test it before installation.

Humpty
Posts: 55
Joined: Wed Sep 16, 2009 9:09 am
Location: Fremantle, Western Australia
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Post by Humpty »

Hey gang.... Long time no chat.... But guess what?.... The POS she no go!
The old girl has been sitting for some time (3 months!), but the last time I drove it, it ran ok... Still a little rich, but ok.... But today I tried to fire her up and I got nothing.... Fuel is there, spark is the there at all the leads when checked against the body, but the spark does not seem strong.

I have played with the wheel and sensor placement a bit the other day.... At TDC, the sensor sits right over the 9th tooth from the gap.... The gap is forward of TDC.

Removed the MJ from the equation, but still no cigar.

Fitted a spare coil pack.... Nothing.

Fitted fresh plugs.... No go.

The MSD leads have never connected to the plug of the coilpack in a positive way, but since there is some spark, the thing should fire....

But alas, she does not.

Ideas?

Humpty
Posts: 55
Joined: Wed Sep 16, 2009 9:09 am
Location: Fremantle, Western Australia
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Post by Humpty »

Sorted..... Bad lead contacts seemed to be the cause.... The leads I had on the car were handmade (by me) MSD leads, using a combination of the EDIS coil plug end (the type without the plastic clips), and locally sourced BA Ford (Oz production car) plug ends.... Ohm resistance was very good across them, but the dodgy connections at either end made them unreliable.... Made a complete new set using MSD fittings on both ends, and all is right in the world once more....

If fact the engine seems to be running better than ever!!! :D

Idle is stronger and more steady, the O2 gauge is reading a good solid 12-13 at idle, and then goes to 11-12 under revs.... Never been that stable before after such a short warm up.... Next test is taking the car for a spin and see how it is under boost.

Happy days!

dr.occa
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Post by dr.occa »

I hope to have my Wankel running a draw through setup eventually AND energized by MJLJ.
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Humpty
Posts: 55
Joined: Wed Sep 16, 2009 9:09 am
Location: Fremantle, Western Australia
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Post by Humpty »

dr.occa wrote:I hope to have my Wankel running a draw through setup eventually AND energized by MJLJ.
How'd you go with the wankel project?

Update on my POS....

Finally got the car to the track last month, after some dyno time a month before.... The difference is mine blowing!

The car is very strong, revs very easily to 6500rpm.... Too easily.... I hit the rev limiter in three gears!!!.... Which obviously killed my ET's.... But the MPH was good at 101mph.... Also have a minor lean out happening in the top end.

So I have played with the rev limiter setup.... I have set the light to 6500 and the limiter to 6800.... I know the engine can handle it so that should be ok.... I have also clocked the fuel screw a little on the adjust-a-jet to give me a little more fuel... Hopefully that will fix my lean issues....

Next thing is data logging.... It's not possible to run a laptop in the car at the track, so I'm in need of another option.... Any ideas for the budget conscious?

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