hi after lots of help from people on here and a trip to the TorqueTune rolling road near newark my car is now running fantastic the engine is a 1.3 xflow with no other mods other than the injection it was producing 55bhp with the carb and is now managing 75bhp megasquirt powered its a nice improvement and very happy didnt expect to get that much extra

i had a set of filter socks on and the power was reduced to 65bhp so set up without them, so what i plan to do is put an airbox on with a single K&N air filter at the front as was told that it would not restrict the airflow as much as the socks.

what size K&N should i put on and how big should the air box be and how far away from the trumpets. have not got that much room underneath the front trumpet is about 70mm from the inside of the bonnet and dont fancy chopping the bonnet again my plan was to take the air filter under the nose cone with a couple of cold air feeds to it infront of the radiator would this be ok and would i be able to make a suitable airbox that would not restrict flow too much in the space i have?

thanks all

Mark

[Edited on 27/10/09 by myeates]

Over a third extra BHP from going EFi and you're not satisfied!!! That's an amazing improvement. Hope I get that many extra horses % when my conversion is done.....

Definately go for cool air feed. I'd go for the traditional slant plenum chamber with the open end near the scuttle but run a nice cool air feed line from in front of the rad in the nose cone straight into the plenum (perhaps with some air dams to force air into the tube). Either that or use a NACA duct in the middle of the bonnet with a tube going to the plenum chamber (bit of a faff when you add / remove the bonnet unless you use some dinky connectors).

Usual rules of thumb

1) plenum chamber at least 1-1.5x engine capacity

2) minimum distance from end of trumpet to far plate of plenum chamber = throttle body I/D (choke size for carbs)

quote:

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Originally posted by BenB
Usual rules of thumb

1) plenum chamber at least 1-1.5x engine capacity

2) minimum distance from end of trumpet to far plate of plenum chamber = throttle body I/D (choke size for carbs)

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Certainly carving foam + GRP / CF is a nice easy way of making a plenum. I did the same to make my K+N to Honda airbox adaptor. Quite simple really...

quote:

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Originally posted by BenB
Over a third extra BHP from going EFi and you're not satisfied!!! That's an amazing improvement. Hope I get that many extra horses % when my conversion is done.....

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so my TB are 38mm so if i make it 45mm out from the end of the trumpet and approx 2 litres in size so its just over 1.5 x 1300cc then thats a good starting point?

it may have been a long old slog to get it this far but with the added power and economy its deffinatly worth the money and wait

Your TB's are actually 35mm - early Gpz1100 - but I would still go with 45mm if you have the space .
I'd try and get at least 3" hose to the filter - that will act as increased volume for the plenum .
Great result with the horsepower increase

Great that's right it's the outside that I'd 38 lol

Wouldn't even have them looking that tidy and started the engine if it wasn't for your help a few weeks ago so thanks very much for you help

gives me something to do this weekend lol

Mark

What a great result! Goes to prove just how crap those filter socks are as well; if they knocked 10bhp of your pretty standard 1.3 xflow then they must be crucifying the power when fitted to tuned 2.0L engines etc.

here's one we made earlyer.........B&Q sq to round also ali flexi duct to suit so simple.......

Who would of thorght b&Q would actualy have somthing that worked....

purdy
Rescued attachment DSC00187.JPG

rs2000 16v with dare i say it.....b&Q airbox bwahahaaha
Rescued attachment DSC00186.JPG

Hey I may be building an air filter for a BEC in the near future. Could you take photos of the process. This foam calving + GRP seems interesting.

Im thinking:
1) Make a foam calve of what you want the INSIDE shape to be.
2) Cover the foam in something to stop it sticking to the GRP glue stuff
3) Once its set break the foam up and get it out. Make sure its all out!
4)Spray or finish however.
5) cut holes and fit bits that need to be fitted.

Sound about right?

quote:

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Originally posted by bi22le
Hey I may be building an air filter for a BEC in the near future. Could you take photos of the process. This foam calving + GRP seems interesting.

Im thinking:
1) Make a foam calve of what you want the INSIDE shape to be.
2) Cover the foam in something to stop it sticking to the GRP glue stuff
3) Once its set break the foam up and get it out. Make sure its all out!
4)Spray or finish however.
5) cut holes and fit bits that need to be fitted.

Sound about right?

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its a fantastic result really happy about it thanks for all your replies will start making an airbox this weekend saves running the engine without any air filters

Now does someonw want to buy any pipercross fliter socks lol