STUART.G Posted May 6, 2007 Posted May 6, 2007 My Westfield has an 1800 Zetec, fitted with a pair of twin 40 webers and a westfield pipercross air filter. this is all factory standard. When the bonnet is fitted, it squashes up against the front half of the air filter, this must be restricting air flow and unbalancing the carb set up. Anyone noticed the same. Thanks. Stuart. Quote
John Loudon - Sponsorship Liaison Posted May 6, 2007 Posted May 6, 2007 Its normal to have a hole cut in the bonnet to give clearance. Quote
red hot Posted May 7, 2007 Posted May 7, 2007 Stuart, i took my car to Northampton motor sport and one of thr first things Troy noticed was that i had the standard Westfield air filter ( same as the Pipercross apart from the name) Did a run with old air filter on 131bhp...run without air filter 140 bhp...ended up rejetting carbs and drilling more progression holes.... cut a hole in the bonnet fitted bigger air filter...drove away with 165bhp....say no more Quote
samcooke Posted May 7, 2007 Posted May 7, 2007 The fliter thing has been done a bit previously, so worth a search, but FWIW I still think a pipercross will flow plenty of air from the sides alone to service 40s on an 1800. The K&N types have a plate over the top and produce similar results to sock types. Flowing more air means needing to add more fuel but won't necessarily bring more power or torque. My bike engine ran beautifully with its (restrictive) air box. Hours of RR tuning with a pipercross only got 5 more BHP, no more torque and less drivability. QUOTE Stuart, i took my car to Northampton motor sport and one of thr first things Troy noticed was that i had the standard Westfield air filter ( same as the Pipercross apart from the name) Did a run with old air filter on 131bhp...run without air filter 140 bhp...ended up rejetting carbs and drilling more progression holes.... cut a hole in the bonnet fitted bigger air filter...drove away with 165bhp....say no more Though that's a pretty convincing case... Quote
red hot Posted May 7, 2007 Posted May 7, 2007 I have to say that i didnt build the car...iwas told it has been ported ...high lift cams..vernier pulleys ect ect and also on 45s..however i have the print out from NH msport showing with squashed filter and without... and thats a lot of gee.gees Quote
GSi Posted May 7, 2007 Posted May 7, 2007 at the recent NMS rolling road mine was about 148 with the filter in place (v8 bonnet) and 153 without the filter/bonnet. Troy said the difference is primarily down to the wrong length trumpets, so I'll be back for a new set, bonnet cut and a new filter too, clear cut difference on the graph - not sure I could tell the difference on the road though Quote
Jenko Posted May 8, 2007 Posted May 8, 2007 While at JKM for our recent RR day....I tried the first run with the small Kand N filters on (twin 40's), and then the following two runs with with them off.........the difference was about 5bhp, but it was evident that there from 3000 upwards there was more HP without the filter..... I have just bought a Pipercross sausage filter, and also Trumpets (which my car did not have), so I'm going to fit this and cut a hole in the bonnet.....I'll report results.. Also, I'm not sure if having the filter out in the flow of air over the car may mean more dense cold air...which may help??.... Quote
Kevin Wood Posted May 8, 2007 Posted May 8, 2007 The other thing to bear in mind is that air under the bonnet of a Westfield is hot. The cooler the air you're drawing in, the more power you'll make out of it. Add to that the fact that keeping the trumpets under the bonnet means they're much shorter than ideal. The downside of having the intake poking out of the side of the bonnet is that it will be noisy, so this could be a concern if you're taking it on track. Kevin Quote
frubpato? Posted May 8, 2007 Posted May 8, 2007 I'm currently trying to find a way out for this as well . I dont want to cut a hole in the bonnet for aesthetic reasons . I am looking at getting a tapered box (ooh missus) and shoving a cold air feed from a remote filter in front of the radiator . Getting the box is the difficult bit . Reverie want 200+ for an empty box and pipercross 200 quid for somethng similar with a panel filter in it . There must be a OE box whcih could be butchered to fit . The other problem you can have with a sausage - on the cvh with jenveys is that it fouls the brake master cylinder . All a bit of a pain Quote
scott beeland Posted May 9, 2007 Posted May 9, 2007 Get yerself a V8 Everything fits under an uncut bonnet; it's quiet..........and it makes sh#t loads of torque Which was "interesting" on the way home from Stoneleigh in the wet Quote
Jenko Posted May 9, 2007 Posted May 9, 2007 I'm currently trying to find a way out for this as well . I dont want to cut a hole in the bonnet for aesthetic reasons . I am looking at getting a tapered box (ooh missus) and shoving a cold air feed from a remote filter in front of the radiator . Getting the box is the difficult bit . Reverie want 200+ for an empty box and pipercross 200 quid for somethng similar with a panel filter in it . There must be a OE box whcih could be butchered to fit . The other problem you can have with a sausage - on the cvh with jenveys is that it fouls the brake master cylinder . All a bit of a pain I'm about to put a sausage filter on a CVH, I've ordered a blank back plate so I can cut my own holes and therefore avoid contact with the Master cylinder..... Quote
Jenko Posted May 17, 2007 Posted May 17, 2007 Just as follow up to this thread..... I've now fitted my sausage filter and trumpets, and cut the dreaded hole in the car..... I can confirm it makes a very obvious difference....the car feels like it has a little more pick up through out the rev range.....AND IT MAKES A VERY NICE NOISE :-) The car is a 2'ltr CVH, so I had to cut out my own base plate (pipercross do a blank).....but it does fit (just without hitting the break master cylinder)....... The filter is 90cm inside and the trumpets are 26mm.... Some Pics: Click 1 Click 2 Quote
sedsy Posted May 17, 2007 Posted May 17, 2007 you could double your trumpet length mate (ooh err) and get some more torque Quote
frubpato? Posted May 17, 2007 Posted May 17, 2007 Jenko That is the neatest hole I've seen. Top marks . I really dont want to do that but I'm almost tempted, I planned on putting a blister snorkel on the side of the nose cone and then duct it to a angled filter box but the hole you made has forced me to think that maybe a side blister facing forward might be better - and give some ram effect at speed. Decisions Decisions ! Quote
Jenko Posted May 18, 2007 Posted May 18, 2007 Sedsy, I thought about larger trumpets, but after a recent RR session, I found the torque on my car to be good enough, so was hoping to concentrate on the top end a little more. I went from no trumpets................. However, I may do some experimenting with trumpet length whan I get some more cash, so I'll keep my eyes open on ebay...... Frubpato - Time to get that Dremel out me thinks :-) Quote
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