okay, this feels like the biggest question of my life, which way do I go, carbs or throttle bodies?
I know throttle bodies are more expensive but offer better maintenance and ease of installation?
carbs being the opposite, cheaper, harder to install.
whats the general opinion as its keeping me up at night!
cheers!
[Edited on 27/3/08 by jimbona2]
How good are you with computers?
I like carbs as their familiar and I can fix them but admit they're no match for an injection system.
im a web developer so not bad
I'd go for a set of bike throttle bodies myself on the Zetec with a Megasquirt. Weber / Dellorto carbs were a pain to keep in tune so if going carbs it would be the bike carbs route for me, but why not go the whole hog and have the even better TB's
whats TB? !! thanks!
quote:
Originally posted by jimbona2
whats TB? !! thanks!
depends on age of engine for SVA emissions test. if post 1995 yoiu need TB and cat.
pre will pass on carbs.
if ^^^ does not apply, then carbs are much cheaper and simpler.
I've gone for carbs due to ease and cost.
No need to plumb in a fuel return etc. Carbs and pump cost £40. Manifold [if it works properly] cost another £20.
Stu
do TBs give better performance?
quote:
Originally posted by jimbona2
do TBs give better performance?
Define better performance?
If you mean more hp or torque then probably not but if you mean useable across the rev range and possibly better fuel ecconomy then you most likely
will get that if they are set up correctly for your engine.
good question, i was initially thinking about the acceleration to 60mph but thats probably a silly thing to think off...?
As mentioned above you will find the driveability improved over carbs. Having driven zetecs with both Dellorto's (my own old Tiger S6), Webers,
and bike carbs, I found the bike carbs gave improved driveability over the Webers / Dellorto's. Bike TB's should be a big step up again in
terms of driveability.
Peak power figures look great on paper, but in the real world you drive on the torque. The ability to really have full control over the fuel mapping
should see you gain much improved torque curves and maybe a little extra power right through the rev range. For this reason alone you should end up
with a slightly quicker car which is smoother to drive.
On the downside, start-up costs are higher as mentioned with the extra fuel return, possibly a swirl pot, dearer megasquirt system etc. Also a full
rolling road session is likely to be dearer but you will benefit from lower ongoing costs. Do the sums i'd say and see what your preference is.
I'd still have to say you should be able to get running on bike TB's considerably cheaper than paying WebCON for a weber carbs / ignition
system for which Tiger are about the cheapest.
It's simple really
There's nothing wrong with a well set-up pair (or more!) of carbs. However, setting it up can be tricky and often gains in one rpm area will be
at the loss of power in other parts of the rev range.
With throttle bodies everything is adjustable and you can iron out any flat areas. It's also easier to adjust and therefore you'll be more
inclined to squeeze out the last few Bhp...
At the end of the day badly set-up TBs will be just as bad as badly set-up carbs!! With carbs you have to muck around with jets, needles and choke
sizes (and you're always going to run into compromises). With TBs you just adjust the laptop
Nothing wrong with carbs- but I'm still converting to TBs...
how much work is involved in bolting the throttle body option together?
any photos of this additional fuel return thingy?
thanks,
Have you got the Tiger injection tank or the standard one at all Jim?? Depending on which will depend on how much work is involved. Standard tank could be used to feed a seperate swirl pot in the engine bay via low pressure pump and then having a high pressure pump in the engine bay to feed the TB's. Injection tank will involve fitting a second pipe to the rear and then using a suitable pump to feed the whole system.
the fuel tank is from tiger.
They do both an injection tank and one designed for carbs. The injection one has a second outlet on the end for the fuel return plus some internal
mods i believe. I would assume therefore that you have the single outlet one for carbs.
I think the best option in this case would be to fit a low pressure pump at the rear and run this to a swirl pot (like
this) or similar. The 3 outlets on the side are for low pressure feed, high pressure outlet and high pressure return. There's
then a breather on top.
From this swirl pot you feed the throttle bodies via a high pressure pump to the fuel rail and then believe you will need a pressure regulator after
the rail before returning to the swirl pot. You will probably want a filter in both low pressure and high pressure lines before the fuel pump also.
Depends how old the donor engine is, pre 95 will be fine with carbs, but the newer you go the tighter the emissions are the more easier it will get
with bodies.
Saying that if I was doing it again I would use throttle bodies with megajolt. Just for the techno factor
quote:
Originally posted by coozer
Saying that if I was doing it again I would use throttle bodies with megajolt. Just for the techno factor
No need for a return if you run a swirl pot up front, then the efi is closed circuit but you do need two fuel pumps.
quote:
Originally posted by mark chandler
No need for a return if you run a swirl pot up front, then the efi is closed circuit but you do need two fuel pumps.
So what happened to the mondeo efi ?
quote:
Originally posted by Paul TigerB6
quote:
Originally posted by coozer
Saying that if I was doing it again I would use throttle bodies with megajolt. Just for the techno factor
Errr you mean MegaSquirt, just for the fueling factor
quote:
Originally posted by Jenko
My swirl pot has an overflow outlet on the top which has to be routed back to the fuel tank.........So, even if the swirl pot is at the front does it not still need some return back to the fuel tank?......The only time I could see this not being an issue is if you have a one way fuel rail set up and the pump regulates the pressure........
how tricky is this fuel return to setup and is this the only difference? unfortunately i just bolted the fuel pump in, i assume the wrong one for TBs as I got the fuel pump from the original bloke that sold me the build.
quote:
Originally posted by big_wasa
So what happened to the mondeo efi ?
quote:
Originally posted by jimbona2
how tricky is this fuel return to setup and is this the only difference? unfortunately i just bolted the fuel pump in, i assume the wrong one for TBs as I got the fuel pump from the original bloke that sold me the build.
hi guys,
i always hear this Megasquirt brand being mentioned, can I ask why? is it the best performer, easiest to install, cheapest??
cheers
quote:
Originally posted by jimbona2
hi guys,
i always hear this Megasquirt brand being mentioned, can I ask why? is it the best performer, easiest to install, cheapest??
cheers
"As regards the swirl pot the top outlet could be used as a breather on a low presure carb system but not with f.i. high pressure as the pressure
from the hp pump will just spew fuel everywhere at low engine speeds surely"
Not so, the EFI pump sources and returns its fuel to the swirl pot, as the volumn of fuel is a constant , the swirl pot just becomes a very small fuel
tank.
A carb type pressure pump keeps this tank topped up, no return required.
There is no high pressure in the swirl pot, this just exists between the pump and the injection rail, as you drive fuel is consumed by the engine, if
you had a perfectly sealed system you would not even need the low pressure pump, its purpose is really to prime the system.
Regards Mark
quote:
Originally posted by mark chandler
There is no high pressure in the swirl pot, this just exists between the pump and the injection rail, as you drive fuel is consumed by the engine, if you had a perfectly sealed system you would not even need the low pressure pump, its purpose is really to prime the system.
ok, got a better idea what it all means now, carbs are cheaper but need more maintenance, whereas bike carbs are more expensive but easy to live with,
and they can provide more performance by changing the settings through a computer. so in effect, the answer to can bike carbs offer more performance
is YES they can.
my only remaining question is what do I need to get a throttle body setup?
i know, that you get/ need the following parts for the carb root but I have no idea what I need for the TBs.
Carb root
==============
2 x twin 45 carbs,
Inlet manifold,
TPS,
Throttle linkage,
ECU,
Wiring Loom,
Trumpets,
Air filters
Throttle Bodies
==============
Throttle bodies (Yamaha R1 or Kawasaki)
ecu
high pressure pump
dont know what else ?
anyone know what you need for TBs?
[Edited on 7/4/08 by jimbona2]
quote:
Originally posted by jimbona2
ok, got a better idea what it all means now, carbs are cheaper but need more maintenance, whereas bike carbs are more expensive but easy to live with, and they can provide more performance by changing the settings through a computer.
hi,
just had a word with Chester sport cars and they only supply the TB kit with the webcon alpha setting which does not come with any software so it
cannot be changed??
so part a) of my question is where can I buy the package I want and b) if you cannot configure the settings yourself to squeeze every last bhp out
then can TBs really offer much more performance?
thanks again
[Edited on 7/4/08 by jimbona2]
Chester Sportscars dont have a supplier for the MegaSquirt as they do for the MegaJolt so have no choice there.
Not sure who the best supplier is for this but plenty of people on here have one so i'm sure you will soon have a recommended supplier and be
able to get a map from someone. These guys do them assembled anyway
thanks for this. scholar engines do the pack for £2k ouuchhh.. but i still want it!
quote:
Originally posted by jimbona2
b) if you cannot configure the settings yourself to squeeze every last bhp out then can TBs really offer much more performance?
Cheapest way to do it Jim is to buy a MegaSquirt kit and solder it up yourself (i built a simpler megajolt easy enough)
Do a search on here for suppliers (here's one to start with right here )
You will then need a set of throttle bodies from a suitable bike such as the GSXR1000 or similar - i'm sure others more knowledgable will advise
suitable sizes but maybe
these??)