injection for 2L VX

[k.russell]

I know tis has been covered quite a few times, but has anyone done this recently, and what route did you take, I have a 92 HPC on carbs has JPE exhaust and i have just fitted dry sump system and uprated rod bolts, have looked into kits from QED,SBD and OMEX,or should i just buy bits from different supliers to make up custom kit, still unsure whether to get a new bonnet and go with tapers or stick with manifold, not looking for big power, just a nice drivable fun road car, have some ideas about airbox, to make it quieter for the future, will put swirl tank on, understand this saves mods to tank and filler, also what ECU, MBE, OMEX, DTA, have had suggestion to put on some really short jenvey TBs on caterham manifold with extensions in between trumpets and TBs (the length of extensions being enough to compensate for the short TBs)and fit air box and intake inside bonnet, drawing air from nose cone, not trying to re-invent the wheel just looking at options. any advice welcome.

[millsn]

You want to talk to Steve Foster

 

Nigel Mills - 2.0 Zetec carbs

[EFA]

Best configuration is 48mm Jenvey SF's and MBE 967 ECU. 90mm trumpets beige bosch injectors and an ITG filter sitting out of the bonnet for a cool charge.

 

For a reference on a similar setup talk to Aves.

 

Fat Arn

 

Slay the K.

 

[Bill Shurvinton]

'best'?

 

By what metrics Arnie. Sure its 'A configuration' but I doubt the best by any verifiable means. For a start 90mm trumpets are at least 3" too short if you want to gain decent benefit from intake pulse tuning.

[I reply to every thread]

I think he means best compromise all round

[Sheds Moderator]

Given that he says he "doesn't want big power just a useable road car" then is there anything wrong with the setup as fitted to the saloon cars? I may be missing something here but this engine gives 165bhp with factory injection, no flat spots, no difficult setup (GM have already done the difficult mapping etc) and 30 odd to the gallon, which just might be the right set of compromises for this particular app. Certainly better for touring than some monster that can pass everything except a petrol station.

[I reply to every thread]

Take it from me. The TB set-up is much better. If you want a Calibra buy one

The factory injection is all a bit bland & uninspiring for a Caterham owner ❗

[k.russell]

OE injection is not what i want also dont think it would fit as there were chassis mods i think, was looking for opinions on different systems, think some are using manifold type system, Steve Foster, Alex i think, also didnt JPE have manifold, thanks also Bill S and Dave J for some interesting ideas regarding intake lengths on previous thread, would also like air box option as in the future the noise thing is surely going to get stricter and for this reason would like the manifold system as the airbox goes out to the side rather than out through the top of the bonnet,appreciate the 48s is good set up though Arnie, and may opt for this.

[EFA]

Kev,

 

"would like the manifold system as the airbox goes out to the side " Doing this causes redirection of the induction flow onm the way in which does rob power. The airbox I have made is designed to work with the SF system, not DCOE styles. I guess the Reverie airbox might fit under the bonnet on DCOE style TB's but the you are sucking air through a rather small intake.

 

 

Please excuse the next para, but I feel obliged to comment.

 

Mr Shurvinton - once again you are misled. What the heck does trumpet length have to do with intake pulse tuning?? Have the knowledge to understand that SF's have variable configuration which allows for a tuned inlet length independent of trumpet length. Who makes these 165mm trumpets then?? I see Jenveys web site is plastered with them 🙆🏻, but then you porbably know more about induction than Richard Jenvey . Of course Swindon adopted all your ideas when they designed their roller barrels - look at the trumpet lengths on them 🙆🏻NOT. You could do worse though, as a Westfield owner I expect you already know that.

 

 

 

 

 

 

 

 

Fat Arn

 

Slay the K.

 

 

Edited by - Fat Arnie on 5 Mar 2004 20:35:22

[k.russell]

Thanks Arnie, have just been looking at jenvey and SBD site, presume the 48SFs are the same as in the 208 kit from SBD,understand these would need new or cutting of bonnet.the taper type kit seems though to be a bit more expensive route, and for a "low" power VX is it really going to make that much difference, I am seeing lots of powerfull fast cars on manifold and am sure this is going to be more than adequate for my usage.still not made up my mind though and hoping someone with the manifold will post with feelings on there system.

[Bill Shurvinton]

Arnie,

 

A combination of textbook theory combined with practical dyno measurements shows that the majority of ITB inlets are far too short. Even jenvey admit that the main cause of lost power is the inlet too short.

In our experience an under-length system is the greatest cause of disapointment, with loss of up to 1/3 of power potential. There are a number of good books on the subject and the serious developer is referred to these and, in particular, dyno trials.

---

As most cars run a short manifold designed for carbs, with ITBs bolted in their place, you end up with an intake that is far too short to bring even the 3rd reflection into play at normal operating RPMs, let alone the far stronger 2nd reflection. I have dyno plots to back this up. Adding length on the manifold pre butterfly can add its own issues, depending on the way you want to go.

 

I make my own trumpet extensions. Flanges are a couple of quid a piece to make up and then you just tig on some pipe.

 

So Richard Jenvey and I are in agreement and you as usual have heared something 3rd hand and lack the analytical ability to understand what it takes to make a good engine package other than waving money at it.

[EFA]

Kev,

 

1. Cutting the bonnet is easy - all you need is a pair of £20 monodex cutters, a flap wheel and some rubber edging like the stuff vehicle wiring products sell for a couple of quid.

 

2. 48 SF's are what is in the SBD 208 kit.

 

3. The shape of the inlet tract makes a huge difference to the throttle response at lower engine speeds. Pickup is much better/smoother - find someone with this setup (its not uncommon) and go for a spin.

 

It really does represent the best known out of the box conversion you can buy.

 

If you email me offline I'll tell you how to save money by missing out SBD!

 

Bill, I take your point but you have me completely misread.

 

 

 

 

 

 

Fat Arn

 

Slay the K.