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Edelbrock 500 v Downdraught throttle bodies Fi

Posted: Fri Dec 07, 2012 5:23 pm
by mgbloke
Seriously thinking about taking the plunge and could do with some info.
I know its going to be VERY expensive but an alternative engine is out of the question.
Engine is a Rover 4.6 taken out to 96mm bore with forged pistons and M238 cam with roller rockers.
Fuel tank has baffles so the pickup is getting fuel even when level is low and has a facility for a return pipe.
Obviously I would need a high pressure pump.
I have a brand new intermediate front cover, the one with the dizzy hole blocked off so could use coil packs and go waisted spark.
Inlet manifolds could be had fron John Eales ( not checked if he still does them ). Looking at Jenvey throttle bodies possibly IDF type.
http://www.jenvey.co.uk/home/twin-throt ... -idf-style

Then there is the ECU maybe the latest megasquirt or similar.
Where can I get more information like what size throttle bodies and what sensors and hardware i would need to make it work.
Not expecting massive power gains but would like an improvement in throttle response and driveability on track.

Cheers

mark

Posted: Fri Dec 07, 2012 5:34 pm
by Cobratone
Speak to John Eales, he occasionally has second hand jenveys, I bought mine that way. On my old 4.8 with mild cam, wasted spark (edis8) and megasquirt with 50mm TB's I ran 307bhp. HTH

Posted: Fri Dec 07, 2012 5:36 pm
by kev_the_mole
Alternatively I have a friend with a Rover inlet and quad IDA carbs for it. He might be persuaded to sell. No electronickery but harder to setup and worse fuel consumption.

Posted: Sat Dec 08, 2012 8:08 pm
by mgbloke
will call john eales next week.
This will be jumping in at the deep end for me so im going to need all the help I can get!
Where would be the place to go to get it all mapped and set up?

Kev sticking with carbs will really defeat the object.

Cheers

mark

Posted: Sun Dec 09, 2012 2:58 am
by Cobratone
If you bought some throttle bodies and a megasquirt I have a base map that would get you running.

Posted: Sun Dec 09, 2012 7:46 pm
by mgbloke
Big Tone
Thats very kind will take you up on that.
Will talk to mr Eales and the collect together the parts over the next few months.
I have a lot to learn!

Posted: Mon Dec 10, 2012 8:25 am
by kokkolanpoika
I will go for approx 45mm Jenvey throttle bodies on 4.8litre.. 50mm is far to big for 4.8litre..
I run my 5.2litre stage 4 engine (+390hp/552Nm) 48mm Jenvey´s.
I have also got MS3X base map if yuo need it.. :)

Posted: Mon Dec 10, 2012 11:18 am
by chodjinn
If I were to do throttle bodies, I wouldn't buy Jenvey purely on a cost basis (they are great, but pricey!). I'd look at using two banks of throttle bodies from a motorbike, get them rejetted with a custom manifold and use megasquirt. :D

Posted: Mon Dec 10, 2012 1:07 pm
by Quagmire
Sensors you need are:

2 terminal Air temp sensor (can be from anything)

2 terminal Water temp sensor (again from anything)

Throttle Position sensor (you guessed - from anything - just make sure its not a throttle switch as *from what I've read anyway* some 80/90's Bimmers had.)

Manifold air Pressure Sensor is built into the MS- you just need to run a small ID vacuum line to it from somewhere. If using individual throttle bodies then you need a feed from each one, all joined together and this is then fed into MS.

Some means of telling the MS what the engine is doing revs and position wise - i.e a toothed wheel and vr sensor or some similar setup.

An oxygen sensor of some description - wideband is preferable for obvious reasons.

Posted: Mon Dec 10, 2012 4:24 pm
by kokkolanpoika
chodjinn wrote:If I were to do throttle bodies, I wouldn't buy Jenvey purely on a cost basis (they are great, but pricey!). I'd look at using two banks of throttle bodies from a motorbike, get them rejetted with a custom manifold and use megasquirt. :D
When i build my throttle body pattern, i first look motorbike throttle bodies, toyota throttle bodies etc.. I made some calculation´s and my opinion is.
You have got more work if using motobike or BMW etc throttle bodies VS Jenvey, and you spend seriosuly money also those bike throttle bodies. You have to buy silicone hoses etc to fit those in the manifold. + Fitting good air filter is quite big job.. Those socks are suck, good big filter is mutch better.

I bought my own Jenvey kit in Finland, it uses John Eales manifold.. Those throttle bodies in Finland is cheaper than straight for Jenvey.. I ask it.. :shock:
Find a Jenvey dealer, they might be cheaper there than factory..

And if i understand correctly bike bodies inc mutch more agressive throttle meganism than car bodies.. So car might be like kangoroo if use bike bodies..

Posted: Mon Dec 10, 2012 5:21 pm
by mgbloke
Thanks for the support guys.
Once I have all the hardware bolted on and its ready to go, how easy is it to tune? Do I need to take it to a specialist tuner?

Getting inlet manifold and bodies from Mr Eales he suggested 48mm

Posted: Mon Dec 10, 2012 6:35 pm
by kokkolanpoika
You do not need special tuner, if you are handy with computers and you won´t burn your brain´s easily.. :lol:

I make my own adjustment´s for street, and when i go to rolling road´s they are 100% perfect. All adjustment what i made, power will drop slightly..
I will say my old Haltech is mutch easier to tune than new MS3X, but MS3X will give me more potential in real life..

Posted: Tue Dec 11, 2012 11:53 am
by chodjinn
kokkolanpoika wrote:
chodjinn wrote:If I were to do throttle bodies, I wouldn't buy Jenvey purely on a cost basis (they are great, but pricey!). I'd look at using two banks of throttle bodies from a motorbike, get them rejetted with a custom manifold and use megasquirt. :D
When i build my throttle body pattern, i first look motorbike throttle bodies, toyota throttle bodies etc.. I made some calculation´s and my opinion is.
You have got more work if using motobike or BMW etc throttle bodies VS Jenvey, and you spend seriosuly money also those bike throttle bodies. You have to buy silicone hoses etc to fit those in the manifold. + Fitting good air filter is quite big job.. Those socks are suck, good big filter is mutch better.

I bought my own Jenvey kit in Finland, it uses John Eales manifold.. Those throttle bodies in Finland is cheaper than straight for Jenvey.. I ask it.. :shock:
Find a Jenvey dealer, they might be cheaper there than factory..

And if i understand correctly bike bodies inc mutch more agressive throttle meganism than car bodies.. So car might be like kangoroo if use bike bodies..
Fair enough, but I've seen plenty of 4-pots done on a budget using bike throttle bodies and a bit of ingenuity to keep costs down. And silicon connectors / air filters are practically free compared to the rest of the costs. Depends how good you are at fabrication I guess!

Posted: Tue Dec 11, 2012 6:24 pm
by Cobratone
kokkolanpoika wrote:I will go for approx 45mm Jenvey throttle bodies on 4.8litre.. 50mm is far to big for 4.8litre..
I run my 5.2litre stage 4 engine (+390hp/552Nm) 48mm Jenvey´s.
I have also got MS3X base map if yuo need it.. :)
I agree, I bought them when I was planning on supercharging the 4.8 so thought they'd flow better. They are currently sat on my 6.3 chevy with Inglese manifold :lol:

Posted: Thu Dec 13, 2012 4:32 pm
by mgbloke
I am now wondering if I need the 45mm throttle bodies as the merlin heads have fairly small ports.
Its a lot of dosh to spend on the wrong size!

Expecting power to be about 330bhp ish so on that basis what fuel pump would be best?