MING Posted October 27, 2004 Share Posted October 27, 2004 🤔 can anyone tell me what power a standard caterham blackbird with carb's should produce (at the wheels ) and has anyone ever got one to work properly with the "standard"(caterham) airbox fitted so many supercars so little time!!!!!! Link to comment Share on other sites More sharing options...
barry.h Posted October 28, 2004 Share Posted October 28, 2004 Is that you Simon? If so, I assume the mods to the airbox didn't produce the desired result? How did you get on with the rolling road? And what did they tell you about the transmission losses? I shall probably have mine rolling roaded later this year so may have something to compare with. Cheers, Barry Link to comment Share on other sites More sharing options...
MING Posted October 28, 2004 Author Share Posted October 28, 2004 hi barry well spotted its me! rolling road session monday started as a bit of a nightmare 1st run: hidious intermitent misfire peak power 100.7bhp @ 7,800 then steep drop off to level out at 70ish bhp for rest of rev range ☹️ (balance pipe still in original incorrect place). 2nd run same ish power misfire cured by cutting tyeraps holding all H.T. leads together .several runs later with lots of dickin with balance pipe's, air fillters in/out ect,ect no obvious increases in power now starting to get v.worried ☹️ ☹️ ☹️ . Man from TTS says ripp that *&%kin orible (his words not mine) airbox off & bin it! RESULT power instantly increases 😳. Several runs later now sporting a TTS foam air filter with one set of jets (no I don't know which ones) completely blanked off & the main's reduced to 136 from over 2mm(drilled out) nice smooth power curve with no dips troughs or hicups making 100bhp by 6,700 120bhp by 8,000 on to a peak of 130bhp at 9,100 staying level for 1500 rpm till a gentle drop away (perfect no point in bouncing off rev limiter) 😬 *cool*. The car is a bit noisier (deep gravely growl) but sould go like a cat(erham) with its 🙆🏻 on fire!! i shall let you know on sunday after the birkett hope it dosn't rain. I asked about power loss due to reverse box its at least 5% but as much as 20% dependant on how exactly it works . So an almost 100% increase in usable power for £300 inc. vat that's what I call good value I can't recomend TTS highly enough. (I also don't feel guilty about winning the up to 1600cc class in the open race at the caterham festival as they had at least as much power as me ❗) cheers MING 😬 so many supercars so little time!!!!!! Link to comment Share on other sites More sharing options...
Ferrino Posted October 28, 2004 Share Posted October 28, 2004 as much as 20% Sounds a bit much 😳 🤔 Lobbying Caterham for a new badge.... Link to comment Share on other sites More sharing options...
MING Posted October 28, 2004 Author Share Posted October 28, 2004 I agree it sounds a bit mich to me to but don't shoot the messenger I asked the question thats the answer I was given ❗ cheers MING 😬 so many supercars so little time!!!!!! Link to comment Share on other sites More sharing options...
barry.h Posted October 28, 2004 Share Posted October 28, 2004 Great. Glad you got a result. You are going to notice a bit of difference on track I think. Presumably the 130bhp was at the rear wheels? It sounds as though it was the jetting that was the problem rather than the airbox given the changes that were made. You might like to think about ducting some cold air to the nice new air filter as it is now sitting in a warm airstream above a hot engine. Nothing elaborate is required - I used tumbler drier ducting and dropped temperatures by at least 15c. Cheers, Barry Link to comment Share on other sites More sharing options...
Peter Carmichael Posted October 28, 2004 Share Posted October 28, 2004 The shape of the curve you get from looking at "at the wheels" figures can be very misleading. Even after the "at the wheels" power has started falling the engine output can still be rising - it's just that the roller losses are rising faster and these are losses that are of no relevance as far as engine tuning is concerned. If you believe "at the wheels" figures, you end up changing gear in the wrong place (far too early). As long as run on run "at the wheels" figures are compared under fairly consistent circumstances, they are useful and it sounds like that was going on. All I'm coming round to is... bang it off the limiter. There is more power up there than you think. 😬 Link to comment Share on other sites More sharing options...
mr_ed Posted October 28, 2004 Share Posted October 28, 2004 I got 132bhp at the wheels with a carbed blackbird engine, thru a quaife reverse box, and an escort axle. On the TTS rollers, a few years ago. Cheers, Ed Link to comment Share on other sites More sharing options...
mr_ed Posted October 28, 2004 Share Posted October 28, 2004 Sorry, forgot to say, that was with the TTS foam filter and jet kit. Not with an airbox. Had a dirty great flatspot in it between 6 and 7K which TTS put down to having a 4-1 exhaust, rather than a 4-2-1. Link to comment Share on other sites More sharing options...
MING Posted October 28, 2004 Author Share Posted October 28, 2004 thanks for all your feedback guys; barry yes that reading was at the wheels and yes I have thought about some cool air, for this weekend I will run with makeshift ducting comprising of original air box snout (i'm thinking high ambient temp not going to be to much of a problem this weekend) for next year possably a modified bike airbox like caterham fireblade (might help muffle induction noise aswell) I don't beleve that most of problems were due to jetting as a massive increase wes found by simply removing the airbox peter c. where's your mechanical sympathy BOUNCE IT OFF THE LIMITER ❗ 🤔 no way not on a regular basis I've got a wife 3 kids & a chancelor to support ❗ ❗ ❗ cheers MING 😬 so many supercars so little time!!!!!! Link to comment Share on other sites More sharing options...
STEVE GILBERT Posted October 29, 2004 Share Posted October 29, 2004 Jets drilled to 2mm? These jets are calibrated in typically 0.005 increments The change from 2mm to 136 is like Mains sewer to sink waste. No wonder BEC's get a bad rap for drivability. This is the 3rd Caterham BEC I have heard of with bodged drilled jets and one of them was Evo TCOTY! Imagine how it could have done with proper jets I wonder if the same monkey did all of them? Steve See My Caterham Fireblade Here. Link to comment Share on other sites More sharing options...
barry.h Posted October 29, 2004 Share Posted October 29, 2004 Simon, So it was the airbox causing problems - I misread your earlier post. 130 at the wheels sounds good and must suggest flywheel bhp around 160 assuming 15-20% transmission losses, etc. Good luck this weekend. Barry Link to comment Share on other sites More sharing options...
Violet Elizabeth Posted October 29, 2004 Share Posted October 29, 2004 Sound like there may be a little more to come then, as blackbirds in other applications are coming up with figures of 170bhp on carbs. Link to comment Share on other sites More sharing options...
barry.h Posted October 29, 2004 Share Posted October 29, 2004 Not without some work. Honda always claimed 164bhp whether carbs or fuel injection - and not a few would suggest those figures were, ah, generous. Barry Link to comment Share on other sites More sharing options...
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