Lipman '72 911T

912uk · Post by **912uk** » Sat Aug 30, 2008 5:16 pm

fitted posh glass inline filter

please tell me your joking.. ? hate these things..

jamie · Post by **jamie** » Sat Aug 30, 2008 9:32 pm

Like this:

Dunno - it's just a filter to stop me getting tank crap in my high-pressure fuel pump

All hidden under that cover at the front, up by the steering rack.

Anyhow, time for another Rolling Update! Like Sky News, but with more intelligent commentary...

I tried mapping the thing this afternoon. It's difficult to adjust anything when you're trying to drive, so I called Paul (Ferryman), who lives a few miles away. He was having a barbecue and told me to basically f*** right off, so I went over and gatecrashed the joint, rock and roll stylz.

After eating all his food, Paul drove my car around furiously whilst I tried to map it. I didn't know much what I was trying to do other than get the lambda sensor to stay at stoic, but the thing was jumping around so much it was hard work to know what was right and what was rich or lean.

We managed to reduce the Kyrgyzstani-guerilla-mortar-crew backfire to a loud pop, but the car still stutters if you wham the pedal to the floor, and it just doesn't pick up and go at most rev ranges. There must be something right in there though, because every now and again it gets it right and will throw you towards the horizon at a fantastic pace.

It reminds me of when I got the car and I tried and tried to get the carbs in tune but couldn't. It took 18 months before they ran sweet, by which time I was bored with them. It is definitely faster, though, even now.

After the mapping debacle, Paul let me drive his S. I knew it would be a nice car, but it really is something special - the throttle is so crisp, it pulls from 2k like you'd expect a modern vehicle to and does that lovely coming-on-cam power surge at high revs. Other interesting differences are that the pedal has way less travel, the seats are a masterpiece, the gearbox is noticeably tighter and it is green. Mine is orange.

I really liked it. If I can get this EFI as crisp as that, I'll be totally chuffed.

Ferry Man · Post by **Ferry Man** » Sat Aug 30, 2008 10:35 pm

jamie wrote:Paul drove my car... ...whilst I tried to map it.
I didn't know much

No, I didn't know much either but we had good fun hooning around.
I probably looked just like Walter Rohl and Jamie looked the part too (with his laptop) and yet neither of us knew what we were doing. Great fun nevertheless.
Maybe we'll try the Nordschleife for our testing in future.

I doubt Porsche will look to either of us to refine their next generation 911.

jamie wrote:every now and again it gets it right and will throw you towards the horizon at a fantastic pace.

It's true. Jamie got a long way to go before everything's on song but it's a fine car already and it is getting better through his efforts. He's got a lovely Porsche there. It's a good car, not that far off an 'S'.

jamie · Post by **jamie** » Sun Aug 31, 2008 1:52 pm

Did a bit more tuning this morning using MSLogViewer's VE Analyser.

Running loads better than last night - got a little stuttery banckfire from 1000-3000 revs, good power like the carbs gave from about 3000-4000 revs, then past 4000 it's like there's a party in the crankcase and everyone's invited. It just picks up and flies. I love it.

It still backfires a bit under heavy load at low RPMs, so I need to sort that. Somehow.

Quite a lot to learn! Fun though.

jamie · Post by **jamie** » Tue Sep 02, 2008 10:13 pm

Done!

Took the car back over to Tim's this morning. We went for a drive down the A3 and he sat on the laptop and got the thing driving fast and clean in less than 20 minutes.

He's a clever sonbitch - he did all the mapping on a number-based (non-graphical) VE table, then only used my WBO2 sensor to verify the engine was running a good state of tune. And he needn't have bothered because he got it 95% right without.

We then spent another hour or so driving about whilst he got rid of little backfires and flat spots.

This evening I went out into the lanes for half and hour with the datalogger running, then ran the file back through the MSLogViewer analyser and got it to adjust the VE table based on it's calculations. It wasn't anywhere near as good. OK, but not fast and snappy and raw like Tim's map.

He said he'd never want to map anyone's car but his own or his friends, and he thought the MegaSquirt software interface was a bit shite. But if anyone ever reads this having done a Bitz EFI conversion on their car and wants the thing to run properly with minimal fuss, I'd pester him to sort it. This is his website: http://www.thephirm.co.uk

I'm totally over the moon with this whole project. The car runs beautifully, with a snappy throttle response and heaps more power, yet still retains that oldschool 911 bark, drive and interface. There's no Idle Stabilisation Valves, Warm-up Regulator or any of that nonsense - just a hand throttle and some pedals linked directly to a big intake!

You can very occasionally catch it out and make it judder on acceleration; it probably needs a few tiny tweaks here and there, but overall it just pulls and pulls and pulls - all the way through, from 1000 rpm (!) to the redline.

I haven't driven heaps of 911s, but of the ones I have, it's one of the best. I love it so much. What a result

Now for the twin EDIS!

jamie · Post by **jamie** » Wed Sep 03, 2008 12:18 am

YouTube clip for engine sound: http://www.youtube.com/watch?v=mX4LBziwuTU

impmad2000 · Post by **impmad2000** » Wed Sep 03, 2008 6:55 am

Good stuff Jamie

The great thing about tweaking is that you can fiddle and fudge all you like, make a real mess if you like , and just re-load the old map when it all gone wrong.
I'm really pleased that you've got it up and running. Planning a trip to Bob Watsons for a little confirmation ? It would be interesting to see the numbers

Tim

Ferry Man · Post by **Ferry Man** » Wed Sep 03, 2008 7:32 am

Excellent news Jamie.
'Look forward to seeing it at Castle Combe on Friday.
Let's hope it's quieter too, eh?

Gary71 · Post by **Gary71** » Wed Sep 03, 2008 7:38 am

...and then get your butt over to Wales so it can be really tested!

Post by **Bootsy** » Wed Sep 03, 2008 8:06 am

jamie wrote:Dhe did all the mapping on a number-based (non-graphical) VE table, then only used my WBO2 sensor to verify the engine was running a good state of tune.

Exactly what I would have done

Well done on getting it sorted Jamie, and thanks for the stickers! Made me laugh out loud.

jamie · Post by **jamie** » Wed Sep 03, 2008 8:10 am

Bootsy wrote:
jamie wrote:Dhe did all the mapping on a number-based (non-graphical) VE table, then only used my WBO2 sensor to verify the engine was running a good state of tune.
Exactly what I would have done

Well done on getting it sorted Jamie, and thanks for the stickers! Made me laugh out loud.

Perfect for the Bumblebee colour scheme - I want to see the turkey on the rear window...

impmad2000 · Post by **impmad2000** » Wed Sep 03, 2008 8:27 am

jamie wrote:You can very occasionally catch it out and make it judder on acceleration;

Do you have a TPS ? (Throttle Position Sensor )
This could help here. It can be tuned for a little extra fueling for Accel enrichment, qty depending on how fast you mash the pedal to the floor.
Might help. I have a spare one if needed, I'll take a look at my CIS throttle and see if it can be fitted somewhere.
Cheers
Tim

58A - 71E · Post by **58A - 71E** » Wed Sep 03, 2008 11:09 am

I think I understood about 10% of this EFI stuff, but that youtube clip helps a lot for simple folks like me - v v impressive stuff, good job

jamie · Post by **jamie** » Wed Sep 03, 2008 4:40 pm

James - about a year ago I knew zero about EFI. I still don't really know as much as I should, but it's not a complex system. You can make it complex, but on a 35 year old car, there's no need. This is why it's so brilliant.

Tim - Still no TPS sensor, and apparently it doesn't need one. This is from the manual:

impmad2000 · Post by **impmad2000** » Wed Sep 03, 2008 6:16 pm

jamie wrote:Tim - Still no TPS sensor, and apparently it doesn't need one. This is from the manual:

OK, doesn't need it, and I'm sure that fine tuning will reduce the effect, but if symptoms persist, try a TPS.
The CIS system as standard doesn't have a an accel enrichment device. but derives a similar effect ffrom the inertia in the air flow plate, An interesting mechanical property that is not present in the EFI setup you have. I'm not too sure how the software derives a similar effect from MAP alone, Rate of change of MAP could be used I guess. All interesting stuff.
Cheers
Tim