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Discussion Starter #1
Hi,

Am looking into getting some throttle bodies for a c16xe.

Are tapered or paralell ones best?

I spoke to Walden Engineering earlier and they said that they prefer parallel ones, they are cheaper, easier to use and produce more power. Although most people sing the praises on tapered ones. That the theory of tapered ones is that they increase air speed but he has found them to be restrictive on a flow bench.

He also said to use 40mm bodies if the engine will only be fitted with tb's, but if you want to go further use 45mm's.

For jenvey Tb's, linkage, manifold, filter, fuel rail, bells, throttle pot and rod bolts he wants £927. Is that a good price? I thought they were less than that.

Where's good places to try.

Any gen?

Cheers

Miles
 

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i dont see any ECU in that list.

The advantages of using Taper throttles over the parallel type

Taper Throttles kit are made up from 4 single bodies (on a 4 cylinder engine) which is 66mm long tapering from a 48mm diameter hole at the ram pipe end down to 42.7mms at the manifold face, with a 45mm butterfly in the middle.

The main advantages of using a tapered singled body over parallel bodies & slides that we have found in tests are:-

1. Being individually adjustable they can be perfectly set-up.

2. We have found that the use of a taper that continues the shape of the ram pipe right through the throttle & manifold up to the valve, has improved torque through almost the entire power band.

3. Also we have found that the use of a 45mm butterfly in conjunction with a taper has improved throttle response.

4. The peak BHP that we have seen from the tapers (with 45mm butterfly’s) is better that we have achieved in similar tests using 48mm parallel bodies or a slide throttle assembly.
 

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wrote this myself honest ;) (leeched from SBD)

The advantages of using Taper throttles over the parallel type
Taper Throttles kit are made up from 4 single bodies (on a 4 cylinder engine) which is 66mm long tapering from a 48mm diameter hole at the ram pipe end down to 42.7mms at the manifold face, with a 45mm butterfly in the middle.

The main advantages of using a tapered singled body over parallel bodies & slides that we have found in tests are:-

1. Being individually adjustable they can be perfectly set-up.

2. We have found that the use of a taper that continues the shape of the ram pipe right through the throttle & manifold up to the valve, has improved torque through almost the entire power band.

3. Also we have found that the use of a 45mm butterfly in junction with a taper has improved throttle response.

4. The peak BHP that we have seen from the tapers (with 45mm butterfly’s) is better that we have achieved in similar tests using 48mm parallel bodies or a slide throttle assembly.

The injectors are the same as the MT system and we use the same ECU but that is where the similarity ends. With a very different programme using this basic kit on a standard 2.0 litre 16v XE engine an output of 208 BHP is achieved. Needless to say we used one of our exhaust manifolds, on a closed cell Dynamometer. It cannot be stressed too highly that the outputs quoted on all our kits will only be achieved if a recommended exhaust manifold is used. Coupled to a good large bore exhaust system.

The same high specification of loom used which is available off the shelf in 3 versions, rear wheel drive, front wheel drive and mid engine versions. These have been specifically designed to be as neat as possible and to cover as many applications. These wiring looms are kept on the shelf with a selection of coil adapters which will allow you to fit to a range of ignition systems e.g. engines with distributors, engines with distributorless coils (Bosch 3 pin connector type as fitted to the LN engines), or by using our coil (COIL-4 listed in the optional extras). Alternatively, you may wish to have a wiring loom custom made to your loom drawing specification, this is not problem, but will take approximately 4 weeks to produce from the receipt of your finished drawing and there will be no compromise on quality anywhere in any of the components. If you refer to the section on ECU’s we have listed all the specifications & options available which you can add. The only optional upgrade that can be done to the standard harnesses before dispatch is the addition of a barometric pressure sensor.

Although the kits do allow you to use the standard distributor/coil amplifier set up, it is not recommended because even if you have these parts, the standard cap & rotor reduce in efficiency as they wear & cost over £60.00 to replace each time. The distributorless coil have no moving parts so it can maintain a perfect spark & we have never seen one wear out yet, making the distributor/coil amplifier set up a false economy.

Where space permits this unquestionably the way to go. Smooth power application, high torque and wide power band, this set up has it all. It almost behaves like a standard production car. Staring is simple and the air temperature sensor & Lambda control will take car of the warm up. Once it has been set up correctly, apart from the occasional set-up to adjust out small wear variants the engine will not need re-setting at all throughout the season. It is extremely reliable and forms the basis of all our winning engine/car/driver combinations. It was using the TP208 that Trevor Willis won the 1996 & 1997 ‘CCC’ Sprint Hillclimb (overall) Championship. Whilst using the TP252 that Steve Broughton won the 1995 ‘CCC’ Sprint Hillclimb (southern region champion) Championship driving in the Sports Libra class and it was with the TP270 that Richard Hulbert won the class in the Brighton Speed Trials in 1996. It is also the same basic kit that OPEL have been homologated with the FIA and SBD for the Astra Mk III kit car for rallying.

So it is with considerable ‘track record ‘ and proven reliability that this style of kit is offered.

Certainly all those who have purchased it are extremely complimentary about it and the reports are continually coming in with very positive results.

IMPORTANT NOTE

The Taper Injection kits will fit most competition & road car e.g. Caterham, Westfield, Novas, Escort MK2s, Opel Mantas, etc. It will not fit the Astra Mk2 & 3 or Cavalier range (left-hand drive cars are no problem). This is because the throttle body & ram pipe assembly nearest the cam pulley end, will cut right through the middle of the master cylinder, so unless the brake master cylinder & servo system is removed & replaced with a custom built bias peddle box, it will not fit. We do not advise this operation to be carried out on road cars, because it is quite an expensive & time-consuming job, but on competition cars it is definitely worth the effort.

Please note that most of the kits do not include oil system upgrades, this is because it will depend on the type of car & the rules of the Championship you will be using it for but it is recommended that a Dry sump system is used if possible. Please read the section on oil systems & ring for more details if you need help
;)
 

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Discussion Starter #9
So you dont reckon I'll get it any cheaper?

Thats with parallel ones that are apparently cheaper, so would I definatly be better off with tapered ones?
 

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yeah tapers are better.

Just looked at SBD site through web archive, and a their price is 808+VAT for just the parts you have listed, but with taper bodies. Quite old prices though, probably nearer 1k now.
 

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Discussion Starter #15
hmmmmmmmmmmmmmm

We shall have a long conversation tomorrow chris on the way to chepstow!
 

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for daily driving i have to say parallels give a nicer power distribution and i know i would get pulled up on saying that so i took the liberty of overlaying the mt215 and tp225 graphs as best i could to show summat interesting...the faded blue&red lines are the parallel kit and the stronger ones are the tapered.



more torque and power till you go over 6k and even there the tapers seem harder to setup as well and i am sure many tp kits could make the extra power, but dont for one reason or another which makes the 2 kits very comparable power wise. hence i went for the cheaper option rather than save for another couple of months.
 

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Paste what you want over the original image as a new layer. Alter the layers opacity settings to get the desired transparancy. Flatten the image back to a single layer to save it.
 

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OMG somebody else did the pastey pastey SBD graph thing I did when I was comparing them!

I would go for the QED direct to head jobbies and get a custom made matched plenum and cold induction system on a road car.
 
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