sonus
Europe
Posts: 1,392
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Don't cut the trumpets. The overall length has an impact on cylinder filling and ultimatly performance. So if some of the cylinders have shorter trumpets they will draw fuel and air differently than the others. I think in worst case you might end up with some lean and some rich cylinders. At the moment I am more excited about your car than my own
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Last Edit: May 13, 2014 6:25:10 GMT by sonus
Current 1968 TVR VIXEN S1 V8 Prototype 2004 TVR T350C 2017 BMW 340i
Previous BMW 325d E91LCI - sold Alfa Romeo GTV - sold Citroen AX GT - at the breakers Ford Puma 1.7 - sold Volvo V50 2.0d - sold MGB GT - wrecked by fire MG ZT 1.8T - sold VW E-golf Electric - sold Mini Countryman 1.6D -sold Land Rover Discovery TD5 - sold
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crahel
Part of things
Posts: 210
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Wow just read your thread. Wow!
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1973 Lancia Fulvia s2 coupe (sold) 1998 Audi a4 sedan (sold) 2000 Nissan maxima (sold) 2007 Audi convertible.
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fer4l
Posted a lot
Testing
Posts: 1,497
Club RR Member Number: 73
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Doubt half an inch would hole a piston or foul a plug but I agree - cut them all or none at all Personally I think they look horny as hell as they are Oh, and beautiful car and great build by the way Cheers Matt
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sonus
Europe
Posts: 1,392
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Current 1968 TVR VIXEN S1 V8 Prototype 2004 TVR T350C 2017 BMW 340i
Previous BMW 325d E91LCI - sold Alfa Romeo GTV - sold Citroen AX GT - at the breakers Ford Puma 1.7 - sold Volvo V50 2.0d - sold MGB GT - wrecked by fire MG ZT 1.8T - sold VW E-golf Electric - sold Mini Countryman 1.6D -sold Land Rover Discovery TD5 - sold
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deanchad
Part of things
http://retrorides.proboards.com/thread/131936
Posts: 142
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Having the inlets say 20mm will only alter the torque curve according to emerald write up? Besides back in the day various trumpet sizes were used on an engine to optimise torque 8 different parts of the curve. Or was is don't just to look cool?!
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sonus
Europe
Posts: 1,392
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Altering the torque curve is effectivly altering the fuel burn. More torque = more air and fuel or a better burn of these. So in my head having different length inlets will alter the fuel burn and might also cause lean or rich cylinders. You could I guess use it to your advantage to get a broader torque spread. I wouldn't chance it, but why not call Emerald (I seem to recall you using one?) and ask. They should know this much better than me
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Last Edit: May 13, 2014 7:34:19 GMT by sonus: Edit highlighted
Current 1968 TVR VIXEN S1 V8 Prototype 2004 TVR T350C 2017 BMW 340i
Previous BMW 325d E91LCI - sold Alfa Romeo GTV - sold Citroen AX GT - at the breakers Ford Puma 1.7 - sold Volvo V50 2.0d - sold MGB GT - wrecked by fire MG ZT 1.8T - sold VW E-golf Electric - sold Mini Countryman 1.6D -sold Land Rover Discovery TD5 - sold
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That was an interesting read, that Emerald article. I suppose rolling the motor over is out of the option to follow the line of the glass...
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goldnrust
West Midlands
Minimalist
Posts: 1,887
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That is looking very cool Back in the day they used carbs not fuel injection. Each barrel of the carb works independently to measure air flow and meter the fuel. So if you've got different trumpet lengths, and therefore different flow rates into each cylinder it doesn't alter the mixture, each carb will keep each cylinder right. Some of the cylinders will be making more power than others, which can make it feel a bit lumpy, but does spread the torque around as you mentioned. The problem with fuel injection is that you're taking 1 throttle position reading, and applying the same amount of fuel to all the cylinders. So if you've got different air flows into the cylinders you'll have to compromise and end up with some cylinders slightly lean and some slightly rich. I've never used emerald, but if you've got an option to trim the fuel amount for each cylinder independently, and have 6 lambda or EGT probe fitted you could map for different intake lengths properly……... Alternatively you could say that this is a road car, unlikely to spend hours at full throttle where a slight lean condition may cause damage and unimportant if it's 1 or 2 horse power down on where it could be, map it very slightly rich at wide open throttle, cut the trumpets and have it looking damn cool. I say bring on the hack saw.
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Last Edit: May 13, 2014 8:04:33 GMT by goldnrust
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crahel
Part of things
Posts: 210
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I say tilt the engine, this will get you the result you want without the rich/lean running problems mentioned above.
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1973 Lancia Fulvia s2 coupe (sold) 1998 Audi a4 sedan (sold) 2000 Nissan maxima (sold) 2007 Audi convertible.
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deanchad
Part of things
http://retrorides.proboards.com/thread/131936
Posts: 142
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I thought about this a bit more. I'm only using a single wideband lambda. Using 6 lambda would be tricky and pricey!
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But using 6 K-type thermocouples with an arduino and a small LCD would be as expensive as 1 wideband controller
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Almost had an accident today too. As I was reaching over to tighten the front fitting, the car fell off the stands. No damage to the car and I suspect it was because there is very little weight holding the stands down. it maybe isn't heavy but it probably would have pinned me to the floor. That got me thinking, how would this look on the drive.... A bit overkill perhaps? That is exactly why I threw my axle stand in the scrap bin, Spend a few quid on some old railway sleepers and chopped them down to handy sized chocks. They don't slip when stacked and are far far more handy than stands and safer!. Oh not overkill but if your gona get a drive lift get a bright pink one......
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May 13, 2014 12:01:46 GMT
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[/ Loads of rude words] man this is good. Been watching it for a while.
Very good.
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May 13, 2014 18:31:07 GMT
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Wow, not quite sure how i have missed this until now but well done that man, truly epic.
It makes me wish i hadnt sold the body off my S3 now, but the chassis will live on (just underneath a different body!)
I can imagine you did upset a few of the purist when you fitted the air suspension, it is something i have also considered doing, and its not like i've let the purists hold me back so far. Have you ever driven the car in anger to see how the suspension performs? How low can you get the car and still have her drive (not comfortably, just movement without rubbing?) If i go with air I'm pretty sure i could get my floor pans on the floor and still roll on 19's. What is the full travel of you suspension?
Keep up the work and updates,
Cheers
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Hi mate, any photo updates on this? I'm there are more than a few of us interested in seeing your progress on the interior?
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Jul 22, 2014 17:22:50 GMT
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Cheers fellas for the comments. I have been in two minds wether to post or not. As the lotus through and through owners would maybe turn their noses up. Ive gone to every length to keep thecar as original as possible so if I decide to return it to standard, I can. Ive source second hand control arms etc so I hqve a second standard set. When I find all the stut picsi will post them up I'm currently fabricating new front control arms so the front can be lowered to chassis or there abouts, well spotted. The rear end was a doddle but the front has been a bit of an issue. Not the modification but stripping the originl 30 year old kit off- Goldnrust, spotted you too have you got a bit of a buil diary? Love the car mateB-) Sorted a sticky rear brake caliper last night so fingers crossed with the weather I will be at santapod the weekend Cheers Dean Hi, I have the white Esprit also on air bags. Yes I also found out the hard way they don't like the Lotus messed with! it did get a bit stressful posting on the TLF but I stuck with it. do you have any issues with bump steer? what PSI you running in the bags? are you running the dampers on a hard setting? hope to have mine on the road very soon and kind of shitting it taking it out for the first time in case it all goes horribly wrong! Rob
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Jul 22, 2014 18:37:36 GMT
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I think I'm going to cut the trumpets to follow the rear window. good idea or no? Trumpet length will have an influence on the torque / power curve. The general rule is that a longer inlet will give improved performance at lower engine speeds compared to a shorter inlet which benefits higher engine speeds. There are numerous variables at play including pulse tuning but essentially the pipe length directly effects the point in the rev range where the highest volumetric efficiency is achieved. To take advantage of this variable length ram pipes are used which shorten as engine speed increases. Running unequal length pipes as proposed may well yield a similar result flattening out the torque curve. The only downside is the potential for tuning to be more difficult as different cylinders are operating under different conditions. I've got some literature on this but it's at work, I can scan the relevant pages tomorrow if you are interested. Personally I'd give it a go! Awesome build btw. James
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Last Edit: Jul 22, 2014 18:38:47 GMT by metroman
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Jul 22, 2014 19:20:01 GMT
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great project, I think if you own a car you can do the hell what you want with it, and if you keep the original parts so they could be refitted then that's a bonus
I'm with the originality freaks when it comes to rare pre-war sportscars, but often they are incapable of thinking outside the box and have no sense of humour & small willies
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Jul 22, 2014 20:46:24 GMT
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I'm with the originality freaks when it comes to rare pre-war sportscars, but often they are incapable of thinking outside the box and have no sense of humour & small willies ...you've checked? Don't cut the trumpets - that sawtooth look is brilliant. *n
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Top grammar tips! Bought = purchased. Brought = relocated Lose = misplace/opposite of win. Loose = your mum
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Jul 22, 2014 21:58:30 GMT
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www.dpcars.net/dp1v8/dp1280.jpgfantastic work so far. A vac formed polycarb airbox over the trumpets with remote filter would help keep the leaves out and still let you see the trumpets
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