DTH will be a neater job,I think Bill said they both flow the same? if you go dcoe type make sure you get a decent inlet manifold,TWM
I'd say DTH would give a smoother inlet and better options for altering the intake tract length but Bill's the man for this question.
I'd say the throttle bodies as they should give similar flow to the carbs, similar power at the top end and more torque lower in the rev range if they're management is mapped properly.
DCOE and DTH are BOTH throttle bodies. Just one are Direct To Head and the others recquire a manifold like carbs.
DTH will give you a bit more clearance in front of the rad too. Either are a better/neater option as there's no ferkuing about trying to adapt them to fit. I have a set of Nissan GTI-r bodies and will need a fabricated manifold for it to go anywhere near the head .........I also got me a mk1 to mess around with to
And just to be a clever clogs, DCOE stands for: DC - doppio (double) corpo (body) i.e. twin choke O - orizzontale (horizontal) i.e. sidedraft E - indicates carb is die-cast DCOE-style throttle bodies just means that the body looks like a Weber DCOE carb. You could just as easily call them DHLA-style bodies or Mikuni PHH-style, seeing as they all look roughly the same.
Less changes in flow direction on DTH bodies and less weight... no manifold to worry about. Shorter induction length than DCOE's depending on airhorn lengths.. DTH works out cheaper than DCOE pair + manifold Actual performance gains/losses... marginal between either. Both will work well, DCOE will work well with suitable manifold. TWM being one such type (IF) its still abvailable (TWM induction sold their manifold business last year) - There are alternative manifolds from Europe however. AVOID Mangoletsi rubbish tho. Loose a lot of power from this. I can do good prices for either type. 45mm bore is about the norm for most engines around. RobT excluded who may well benefit form 48's now with his spec motor. (we will see one day)
Cheers all... thenoymike - wasn't laughing at you for asking, was laughing because i knew it would be said.
DCOE type places the injector further from the valve than conventional 4- injector DTH type. This gives power benefits at (quite a bit) higher revs. (look where an injector is usuallly in race engines - outside the trumpet !) DTH gives better performance at lower revs and better throttle response. Going to try DTH 48's next year to see what happens (although are a bit loathe since my engine has cracking midrange now and 48's may upset this - but I hear others have tried bigger TB's and got more everywhere when the engine can take it....) - very tempted to try 8- injector also which may give best of both worlds - and then it gets complicated as do you use 2 sets firing at once / smooth swap over / stepped swap over................... Cheers Rob
The main issues are price and space in the engine bay. It was cheaper for me to get my DCOE's custom made down here, even with a manifold, otherwise I probably would have gone with Bill's DTHs. Mine are very good quality using aircraft needle bearings for the shaft and high quality alloy, but I think Bill's are of an equal standard (?). My intake manifold is ABSOLUTELY pooE, so I'm currently looking at other options or getting a friend to machine one up. I took this pic last night and it shows that there isn't much space in the bay: All the airboxes I designed choked the airflow too much. I understand the DTH bodies provide more space, although IIRC, they rake at a very steep angle meaning bonnet clearance may be an issue in a Mk1/2. I'm only guessing though. As has been said, either option works great, though and if you have the money, it's not a waste once they're well setup.
If you want some prices of the kit drop me an email and I'll send you the list and breakdown. bill@badger5.co.uk
