Throttle Bodies...

4684 · Post by **4684** » Tue Feb 28, 2012 4:02 pm

First post so hello all,

I'm looking at ditching my webber 500 and megajolt for injection on my Rover 4.6, after some heavy reading, its odvious the Rover V8 presponds best to Injection, with this in mind I'm looking at TB's

Now asuming that TB's will be my best bet, and perform better than any of the Rover/TVR/ twin plenum jobbies, the only way to get better than TB's is to make something totally wild from scratch, yes?

I'm looking to wack megasquirt on there as well to run both ignition and fueling... I'm not sure witch MS yet though, what I do like though its possible to run a Knock sensor, witch is good.

Question is though... I'm looking at GSXR1000 tb's, are these good for the job or a little big, can I get away with smaller ones?

Also I already have my crank position sensor, but the extra sensors I'll need will be TPS, MAP, Lamda and Knock will I require any others?

With a standard rover inlet at £150 on ebay, and two sets of GSXR TB's comming in at £200... You cant moan

however, heres my dilema...

I'm well aware that on the rover inlet manifolds, the length of trumpets/tracts heavy affects the torque of the engine... If im using TB's with a very simple flange/straight alloy pipes with the TB's mounted to that, is this likly to fook my torque and just generate all out HP's be crap on the road and good on the strip or will it still provide good torque and drivability for the road?

Me and a friend sometime ago, made an inlet manifold for a Zetec engine, extremely simple, how ever I was told because it was just simple pipes with the injectors right near the port, it would fowl up low end torque and only rly be any good on the strip

however this manifold was never fitted, this puts me off as the car is for the road, and leads me to think I should be going for a rover inlet manifold and just doing alot of work to it, in the form of matching the manifold and shortening the trumpets slightly, and blending the base, and maby a twin TB plenum or a bigger single TB. Was there a Rover inlet thats a better base to start with than any of the others?

Thanks for taking the time to read!

DaveEFI · Post by **DaveEFI** » Tue Feb 28, 2012 4:31 pm

If you go for a MegaSquirt MS2 V3, you can't go far wrong, as it can do pretty well everything. The V3.57 is near identical, but factory made using surface mount components. That should make it possibly more reliable, but also makes it more difficult to repair if anything should go wrong. The V3 can be altered/repaired by anyone with decent soldering skills.
I'm not saying it will go wrong - mine has been exemplary - and of course you can build the V3 from a kit.

As regards using throttle bodies - TVR etc thought it not worth the bother?
Different, perhaps, on a high revving race engine - but few RV8s can exceed 7000 rpm. With the vast majority 6000 is more like it.

kokkolanpoika · Post by **kokkolanpoika** » Tue Feb 28, 2012 4:41 pm

Mine are worth up to 40hp.. jenvey throttle bodies, Eales manifold etc.. Ex setup 45mm trumpets, siamesed plenum etc.. 5.2litre stage home/4

Our Finnish Rover forum: some pic:
http://www.roverfriends.fi/foorumi/view ... sc&start=0

also:

http://www.v8forum.co.uk/forum/viewtopic.php?t=9620

kiwicar · Post by **kiwicar** » Tue Feb 28, 2012 4:52 pm

Hello and welcome,
Can't you just strip the throttle plate of the bottom of the carb and use that with a carb spacer plate on the inlet manifold you have and a set of injector bungs welded into the manifold by the ports? infact any 4 hole throttle plate set up would do it. Maybe somthing like this http://www.ebay.com/itm/HOLLY-4-BARREL- ... 0507627232
Really though the straight rover efi manifold is pretty good with a decent ECU
Just seems alot simpler than hacking up an injection manifold and trying to some how graft a set of throttle bodies on.
Quite honestly in the state of tune you are likley to get a rover V8 there is little point in worrying too much about induction length, accurate fuel metering at part throttle and at low revs full throttle will gain you far more (against a 4 barrel leaky bucket) than having short induction lengthes will loose you.
Best regards
Mike

stevieturbo · Post by **stevieturbo** » Tue Feb 28, 2012 6:39 pm

While not ITB's as such. Starting from an SU Boxer manifold is pretty close and should be easy to add injectors to and source throttle plates for.

DaveEFI · Post by **DaveEFI** » Tue Feb 28, 2012 8:30 pm

kokkolanpoika wrote:Mine are worth up to 40hp.. jenvey throttle bodies, Eales manifold etc.. Ex setup 45mm trumpets, siamesed plenum etc.. 5.2litre stage home/4

Our Finnish Rover forum: some pic:
http://www.roverfriends.fi/foorumi/view ... sc&start=0

also:

http://www.v8forum.co.uk/forum/viewtopic.php?t=9620

Well, yes. But there's no 'standard' induction system designed for a 5.2.

4684 · Post by **4684** » Wed Feb 29, 2012 12:36 am

http://www.ebay.com/itm/HOLLY-4-BARREL- ... 0507627232

now thats interesting! I had no idea you could get them...

and I'm guessing you would just put an airfilter on the top?

Injector bungs near the ports on my offenhauser manifold one of them on top with an air filter... I like it

ian.stewart · Post by **ian.stewart** » Wed Feb 29, 2012 9:15 am

Bogg Bros, make a manifold to suit bike carbs/itbs, TVR did make split manifolds to take Jenvy ITBs and so did Mangolesti??
http://www.boggbros.co.uk/

I ran jenveys on TVR Power split manifolds for ages, and loved the things, never go out of tune like Webbers, once set up, they are stonkin, With the setup I ran, 7k was not an issue,

unstable load · Post by **unstable load** » Thu Mar 01, 2012 8:24 am

I have a link on my browser that is to one of the Megasquirt forums but it is blocked on my laptop, possible because I am in Nigeria at the moment. I saved it because it had a load of info and pictures of bike throttle bodies and carbs too.

Here's the link.... http://www.msefi.com/viewtopic.php?t=6627

Here's the message I get...

You aren't allowed to view the page you have requested.

Note that repeatedly requesting pages to which you are not allowed may result in your IP (41.203.68.42) being banned from all our sites. So please search for a legitimate link in one of the above web sites before that happens.

If you have been locked out of the site(s) and you have not been trying to disrupt it, you can contact the Forum Admin Team to see if they might allow access for you again. Please include your forum username and your IP in any emails.

DaveEFI · Post by **DaveEFI** » Thu Mar 01, 2012 9:31 am

unstable load wrote:I have a link on my browser that is to one of the Megasquirt forums but it is blocked on my laptop, possible because I am in Nigeria at the moment. I saved it because it had a load of info and pictures of bike throttle bodies and carbs too.

Here's the link.... http://www.msefi.com/viewtopic.php?t=6627

[snip]

I'm registered on that forum, and get 'The requested topic does not exist.'

stevieturbo · Post by **stevieturbo** » Thu Mar 01, 2012 9:42 am

Not registered and get same message. A search might reveal the topic, as sometimes I get that with links on other forums, but the topic is still there.

Here's a man that knows some stuff too, he'll maybe appear on the thread.

http://www.mez.co.uk/ms10.html

4684 · Post by **4684** » Thu Mar 01, 2012 12:25 pm

I won't bother starting another topic, it leads on really...

Dual plane and single plane manifolds...

What is the point of putting injection on a dual plane manifold, surly the isues with low end torque found with single plane manifolds are over come with injection?

stevieturbo · Post by **stevieturbo** » Thu Mar 01, 2012 1:47 pm

4684 wrote:I won't bother starting another topic, it leads on really...

Dual plane and single plane manifolds...

What is the point of putting injection on a dual plane manifold, surly the isues with low end torque found with single plane manifolds are over come with injection?

Injection doesnt alter how air flows or the speed it flows.

kiwicar · Post by **kiwicar** » Thu Mar 01, 2012 2:04 pm

Hi
A valid observation and to an extent true in that fuel injection close to the valve overcomes the poor atomisation and distribution problems that lead people to fit 2 plane manifolds. Stevie is also correct in observing that the airflow charictoristics of the two sorts of manifolds remain the same (well virtually in that there is no fuel suspended in the airflow). To me it would seem, if I had no existing manifold to go for a single plane and inject at the ports, it will be much better low down than a single plane and carb, and close to a duel plan and carb for throttle responce and part throttle running (provided the cam isn't too mad) If I already had a dual plane manifold I would modify that(it would be much cheeper) and maybe use an open spacer if I could fit one, and possably renove the devider in the plenum.
Best regards
Mike

4684 · Post by **4684** » Thu Mar 01, 2012 5:59 pm

My train of thought on it...

dual plane, there is two cavitys... one primary and secondary feeds 4 cylinders, the other primary and secondary feed the other 4 cylinders, almost like the manifold being totally devided in to two!

single plane, its all open inside and both primarys and both secondarys feed all 8 cylinders

and the reason for this would be, at low end revs the vacume pull on the carb primary is very small, so dual plane, means only 4 cylinders pull at one primary not both, so it creats a restriction... then the other 4 cylinders pull at the other primary

I think I've got the cylinder order right

1357 pull at one primary and cylinders 2468 pull at the other primary, and the same with the secondarys

but then in high revs, this would creat a restriction odv because only 4 cylinders can pull from each secondary... not all 8 pulling together at both secondarys

So right (my brain herts now, but I love it)

With fuel injection the entry is no longer the place where the vacume is measured for the mixture as it were, instead its a MAP sensor much further down the manifold, so now where it used to be an isue, this is no longer the vacume point... all that area is now is the intake...

the other point... why do they not make a manifold thats semi plane, so the primarys are planed but the secondarys arent? Crikey trying to work this out and picture it... you would need a valve in there somewhere...