skymike Posted May 9, 2007 Posted May 9, 2007 I have a 2.0l zetec running twin 45's - the engine is a 1994 zetec and is currently producing about 160-165bhp using a fast road cam. Can anyone tell me what the benefits/power gains are using throttle bodies and what I would need to do to my engine to fit them. Is this only done to cars running fuel injection? I am a bit clueless about engines and am trying fast to learn! Quote
westy666 Posted May 9, 2007 Posted May 9, 2007 Throttle bodies *are* "fuel injection" and can go on any car regardless of its original inlet system/type. The main difference is you have a throttle body per cyclinder rather than just the single one that you find on most day to day tintops. Some of the more frequently quoted benefits over carbs ... "more power" - i think its generally agreed that you dont actually get extra HP from replacing a pair of well setup carbs with some TB's "improved efficiency" - rarely argued about - as the fuel is delivered more precisely with a TB system it tends to be more efficient "improved driveability" - gets debated quite heavily by carb guru's but many say that the car is transformed with TB's when driving at lowish round town speeds "increased torque" - again gets debated quite heavily by both camps. To fit them to a carbed zetec you'd probably need a new fuel tank or a fuel swirl pot, new fuel hoses, a high pressure fuel pump, an upgraded/new ECU, a fuel pressure regulator, fuel injectors, a load of additional wiring, some extra sensors ... and some throttle bodies. Cost is gonna be from the 500 mark upwards depending on the route you take & how lucky/interested you are in hunting around on the likes of ebay. All that said, unless theres something really offending you about the 45's there's nowt wrong with them and are quite capable of supporting a 200+ bhp engine. Oh & just to caveat my before the TB & carb evangelists decend on us ... I aint no expert either Quote
MAT1800 Posted May 9, 2007 Posted May 9, 2007 A fair assesment there IMO.. Except you forgot to mention that TB's just look far er !!! Quote
corsechris Posted May 9, 2007 Posted May 9, 2007 Not on the Zetec, but did a carb to TB conversion on the X-flow a couple of years ago. Carbs were pretty well set up and the car went well. No holes/pops/farts. Went to 3D ignition first which made a minor improvement, when the TBs went on it really was transformed in terms of driveability. Was really quite surprised how big of an improvement it was. Didn't get it RRed but it felt more powerful for sure. Feel free to 'discuss' this! Same setup was transfered to the Zetec when that went in last year. As I already had an ECU lying around idle, I didn't have this cost to cover. I used GSXR600 TBs which cost me about £100 IIRC, plus some old DHLA 45s to provide the mounting flanges. Treated it to a PiperX filter. Starting from scratch it could cost you quite a lot for arguably marginal improvements depending on how you went about doing it and how well sorted the carbs are. As Westy666 says, if it ain't broke, why fix it... ...unless you really want to Quote
stu999 Posted May 9, 2007 Posted May 9, 2007 Through the winter, I converted my XE powered car to throttle bodies from a pair of 45 Webers, and a 3D ignition system. For me, the conversion wasn't a fair comparison as far as performance is concerned, as I replaced the carbs and manifold with a set of 'direct-to-head' throttle bodies. You can buy throttle bodies as a direct replacement for sidedraft carbs (or convert some motorcycle TB's to fit), but as I wanted to fit a big airbox, I needed to get rid of the bend that the carb manifold has to have to keep the carbs level. The by-product of this is that the inlet tracts are starightened, possibly giving a little more performance. It certainly is a lot healthier now... But in terms of driveabilty, it is like night and day! If I am 'pootling', I merely leave it in fifth gear now at anything over 20mph It has also tranformed the fuel consumption. Again, when pootling, I reckon I am getting almost half the mileage again, compared to carbs. Even if you didnt get any performance gain, IMHO the driving experience is improved enough to make the investment worthwhile. And any future upgrades are far easier to optimise too Quote
westy666 Posted May 9, 2007 Posted May 9, 2007 QUOTE but as I wanted to fit a big airbox ya not ****** joking there are ya stu ... I nearly lost me rucksack in it at the wknd Quote
stu999 Posted May 9, 2007 Posted May 9, 2007 but as I wanted to fit a big airbox ya not ****** joking there are ya stu ... I nearly lost me rucksack in it at the wknd Quote
perksy Posted May 9, 2007 Posted May 9, 2007 I'm sure i saw a Squirrel and a Blackbird get sucked in there on the way back from Stonleigh Quote
fatbaldbloke Posted May 10, 2007 Posted May 10, 2007 I've nearly finished the conversion to TB's on my 2 litre Zetec. Hoping to start it up next weekend. I've used GSXR600 TB's and machined (or more accurately, had machined) a little sandwich plate that adapts the existing manifold to the TB's and another adaptor to connect to the Weber trumpets, so the air cleaner ends up in exactly the same position as it did with carbs - to fit the hole in the bonnet. I've had a swirl pot and fuel rail fabricated (friend at work), bought the pump, sensors, TB's and pressure relief valve of ebay, and bought a megasquirt kit which I've put together myself and wideband lambda sensor from Bill Shurvinton. I didn't want chunks of blue hose and jubillee clips all over the place, so I've tried to do a nicely tailored engineering solution - and I think it looks OK. (I'll post a few pictures when it works). I've taken loads of pictures if it would help anybody - I might try to write something up when I have an idle evening. Total cost has been about £650, but I've sold the old carbs, pressure relief valve and megajolt for £350, so total cost about 300 of your english pounds. Quote
westy666 Posted May 10, 2007 Posted May 10, 2007 pics would be ace FBB when you get a chance ... bike tb install is one of my winter plans so the more desgin options the better Quote
fatbaldbloke Posted May 10, 2007 Posted May 10, 2007 No problem. If it works I'll pop out to a local club meet as well. Quote
nre Posted May 11, 2007 Posted May 11, 2007 Plenty of info and pics of my TB conversion HERE if it helps... Quote
fatbaldbloke Posted May 11, 2007 Posted May 11, 2007 All the mechanical stuff is now complete, I just have to fit the ECU and the lambda sensor. Quote
westy666 Posted May 11, 2007 Posted May 11, 2007 looks a nice clean install FBB adapter plate looks a tidy idea. NRE ... I have plundered your website on many a dark evening, its a great resource that Ive also seen referred to on a number of other forums btw Quote
nre Posted May 14, 2007 Posted May 14, 2007 NRE ... I have plundered your website on many a dark evening, its a great resource that Ive also seen referred to on a number of other forums btw Glad you found it useful... Quote
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