Intake Trumpets

General General Lotus Talk
1

Strange question I know - I’m just too lazy to take the air box off … but anyone know the length of the standard intake trumpets inside the airbox ?

2

50mm i think, but dont quote me [image]http://www.exiges.com/ubb/NonCGI/images/icons/smile.gif[/image]

3

Cheers PhilI was chatting to a Rover K series engine guy - he reckoned for best performance the total intake length from end of trumpet to head was xx ( can’t remember exact doh ! ) but anyway that meant that the trumpets needed to be at least 3/4 of the depth of the airbox - at about 50mm they are way off.Its probably very suble but neverless …

4

As your guy said its not just the trumpet length, its the whole distance from the inlet valves to the end of the throttle bodies, the Exige throttle bodies (titan) are quite long and only need short trumpets, the most popular bodies used on the K series are the Jenveys which are shorter than the Titans and have the butterfly in the middle of them where ours have it at the airfilter end, hence lumply low revs running but great at high revs!, various trumpet lengths have been tried on the Jenveys with only a few ft lbs of torque difference.You will need to spend time on the rolling road to get correct trumpet length for your car, could be time consuming and expensive for only a little gain.

5

Had to take my airbox off as was getting flames out the back the throttle bodies…too much air and weak mixture at tick over, all fixed now btw…anyway the trumpets are actually 45mm.

6

Thanks Phil - glad to hear you solved the flames …Reading all the Blah blah about the new ECU it seems a complete induction overhaul and aftermarket ECU is really the way to go anyway - something else the Rover bod said [image]http://www.exiges.com/ubb/NonCGI/images/icons/rolleyes.gif[/image]

7

Well i have the Emerald M3D installed but will be keeping the standard throttle bodies etc, the only thing i might change is to swap the trumpets for some flared GRP versions instead of the ally straight ones.It was worth 5 BHP on the jenvey’s so may do the same for Titan Motorsport ones [image]http://www.exiges.com/ubb/NonCGI/images/icons/smile.gif[/image]

8

Phil, I have been thinking about that, this is almost the only option left, where I could improve, will probably do that next yearlooking forward to your results next week [image]http://www.exiges.com/ubb/NonCGI/images/icons/grin.gif[/image] [image]http://www.exiges.com/ubb/NonCGI/images/icons/grin.gif[/image]later,Bruno

9

Bruno [image]http://www.exiges.com/ubb/NonCGI/images/icons/grin.gif[/image]Its being mapped on Tuesday so fingers crossed [image]http://www.exiges.com/ubb/NonCGI/images/icons/smile.gif[/image]BTW the oval tail pipe is bloody loud, i’m having the oval section cut off and an extension pipe welded in, in a similar way to the super sports, the guy who is doing it used to do them for the Williams F1 team, so i’m having an off-cut from an F1 exhaust system he he

10

Phil, sounds good to me, I will get the oval pipe tomorrow…at last…let me know wheter your posh F1-rebuilt [image]http://www.exiges.com/ubb/NonCGI/images/icons/grin.gif[/image] [image]http://www.exiges.com/ubb/NonCGI/images/icons/grin.gif[/image] is cutting the noise down…if yes, I need one as well…I’m almost deaf already [image]http://www.exiges.com/ubb/NonCGI/images/icons/shocked.gif[/image]looking forward to Tuesday, then… [image]http://www.exiges.com/ubb/NonCGI/images/icons/grin.gif[/image] [image]http://www.exiges.com/ubb/NonCGI/images/icons/grin.gif[/image]later,Bruno

11

Hi Bruno, yes the pipe will work, i had a piece of mild steel pushed into it at first and it was quieter, but that one fell out at 130 [image]http://www.exiges.com/ubb/NonCGI/images/icons/blush.gif[/image]