im wanting to upgrade my throttlebody to a 65 mm with a throttlebody spacer, will i have to upgrade my injectors and fuel rail as well? what are the pros and cons. any suggestions or solutions would be greatly appreciated!
Well, first off, the throttle body spacer is a junk mod. There is no point to it. Maybe on a big V8 it might help, but for a 4-banger, 1/2" longer runner isn't going to do anything for you. Besides, 4-cyl's make their power up high in the RPM range. A TB spacer is more for low-mid range torque. If anything, you want a shorter runner and higher rev limit (along with cams to handle them).
Also, unless you have some serious, serious engine mods, (or boost), a larger TB isn't going to help you. Not only that but I have heard quite a few horror stories about the quality of the aftermarket Focus TB's, and the problems they cause.
If you decide NOT to heed my advice, you don't need to worry about your stock fuel system. You're not really changing anything with a larger TB or TB spacer. You really don't need to worry about the fuel system until you hit ~250hp or so.
What mods do you have done already? If you want my advice, I can surely give it, and I know I can steer you in the right direction.
The 65mm throttle body will only give you a lot better response on the throttle. You do not need to modify anything. It will work with stock stuff. It is actually a bit too big for the motor in stock form but still works fine. No HP increase and I did see a 1mpg increase one one of my cars.
As for the TB spacer. doesn't do a danm thing and is a waste of money. If you have a carborated car they are great but do nothing on a fuel injected car.
im actually trying to get rid of the "hover" between shifts, ive been told a throttlebody upgrade or install a lightened flywheel would do the trick, as for mods, i have a metal mesh cone filter made by REI, factory 6 spoke aluminum 205/50/16's sumitomo Zrated tires, FC lower rear motor mount, polyurethane bushings on the front and rear factory sway bars, dropzone suspension kit, shocks, struts, and springs (1.8front, 1.8rear), uninstalled beause im not sure if i need a camber kit(1 or 2 kits), full exhaust upgrade, header, hi-flo cat with a 2.25 magnaflow catback system with a 3.5 inch tip, i got tired of the braap,braap coffee can muffler! it has a deep agressive tone when i flog it down the interstate, believe it or not you cant hear it when i have the cruise control on. i need input on a clutch and flywheel upgrade(original clutch, 112,000 mi.) diablosport programmer and intake manifold
Last edited on Sat Mar 8th, 2008 01:21 am by n2focus
I don't think a TB will do it, but a lightened flywheel would. However, don't get too light of a flywheel. Your car's drivability will suffer severely.
Why are you trying to get rid of the "hover"? It's actually good all the way around. It keeps the revs up, which gives you a little extra "oomph" when you hit the next gear. It also helps with fuel economy and emissions.
Another quick tip: shift at 6200 and don't lift to shift. That's what the rev limiter is there for
Just out of curiosity, what intake manifold do you have?
Oh I misread your post. You said you need input on "a clutch and flywheel upgrade(original clutch, 112,000 mi.) diablosport programmer and intake manifold."
The early 2000 manifold is the way to go here. You can find them for sale on eBay regularly, and if you ask around, I'm sure someone has one they'd let go. The early 2000 manifold is 1-piece and flows better than the later manifold, it's worth a couple horses. Other than that, there really aren't any great manifolds for the Zetec. I'm planning on custom making mine for my turbo setup, this style:
But here again, unless you have some major internal engine mods or boost, there is no need to go beyond the 2000 manifold, except maybe porting it and porting the head to match.
Clutch and flywheel- since you don't have any internal engine mods, the lightened flywheel really won't help you. A lightened flywheel is really only good for a heavily modified N/A motor, one that has a wide powerband, or a supercharged motor (again, wide powerband).
A chip WILL help you. A chip is a great mod, even for a very lightly modded car. You'll see a few extra ponies, and that may actually get rid of your "hover" issue / non-issue.
You said you have a high-flow cat, did you also replace the flex section? if not I'd do so first thing. Your exhaust is only as open as it's most restrictive part.
I guess what it comes down to is this, your car is at a point where you have to decide if you want to boost it or keep it N/A. You have all the bolt ons, and really can't go any farther without some sort of serious mods.
So here's my suggestions:
Keep it N/A: Get some cams / gears, shave the head to raise compression, and get a chip. Maybe even a little nitrous for when you really want to give 'er. Make sure you spend a little dyno time with the cam gears. The butt dyno is fairly inaccurate on that.
Go full-bore nitrous: Just like it sounds. Upgrade the fuel system with bigger lines up to the FPR, and convert it to a return system with a return-type aftermarket FPR (run a line back and splice it into the fuel fill tube- a little tip I learned from the SRT-4 guys). Get a decent wideband O2 sensor (NOT a controller, just the sensor and gauge). Cold plugs. Nitrous cams. 100+ shot of the giggle gas, extra wet of course. This is actually my plan for my current motor until I can afford to do my turbo.
Boost with a turbo: There's enough turbo advice out there already, but if you want to keep it simple, you can't go wrong with a FocusSport or other aftermarket kit. If you're feeling advanced, build your own. A used Mitsu turbo off a DSM will suit your otherwise unmolested engine nicely, will add a nice amount of "oomph" and is pretty cheap (I bought my 14b freshly rebuilt for $150). You'll need tuning software and some bigger injectors, but other than that, your stock computer will handle the dirty work.
Boost with a supercharger: Did somebody say Powerworks?
im prefering to go with the n/a setup due to the fact of my previous car, a 97 dodge neon. dohc stroker , balanced and blueprinted, stage III cams, cam gears, lightened flywheel, every internal moving part was from SCAT performance, indy head with 3 angle valve job, high rev valve springs, titanium seats, ported and polished, indy intake, mopar performance ECU stage III clutch, LSD with a QUAIFE diff and 4.06 gear set, 324 h.p./338ft/lbs of torque at 6800 rpm, with a redline (rev limit) of 8200rpm. $12,112.64 worth of eng./trans./exh./ susp. upgrades. im not going that route with my ZTS, just upgrading the susp./clutch,cams, cam gears, and intake manifold, just enuf to hit 180-200 max h.p. just curious, is the pic of that intake manifold for a zetec? it looks very breatheable!
I really have no idea. I'm sure if I make one I can make more, if there's a demand. It's not for a while before I plan to make mine though. For the meanwhile I just plan to use the early 2000 mani.
this is my first ford, i dont really know much about them, if it was a dohc neon i could build a 300h.p. v-8 eater in my sleep. do you have any suggestions for a good cam swap, lifters, cam gears, clutch, and chip? im about 20 minutes away from C-F-M, (central florida motorsports) in orlando florida, they deal in performance upgrades strictly for the focus, i just recently learned about them, im unsure of their business practice/etiquette, public relations. i spoke with them earlier today and they told me i need to bring the car to them to get a better idea of what i want but i figured i'd ask you first before i commit.
Last edited on Tue Mar 11th, 2008 10:59 pm by n2focus
Well honestly I have never heard of a 300hp N/A Zetec, although I'm sure it could be done.
You're obviously going to need headwork. The Zetec head (stock) is pretty restrictive from what I understand. I'd upgrade the oil pump, there's one out there with billet internals which was good for 8k+ rpm. The stock one fails around 7500. As for cams, I'd assume a similar life + duration combo to what you ran in the Neon would be good here. The stock SVT header is still the best header there is for the Zetec, and you're going to want to get rid of the cat and go with a large flex section to match.
As for C-F-M I've never had any dealings with them, but I have never heard anything bad about them.
When it comes to building an engine, a lot of your Neon experience will carry over to the Zetec- an engine is an engine, and if you understand how to build an engine, you can essentially build any engine. The brands may be different, the parts may not look the same, but really, it all comes down to "suck, squeeze, bang, blow".
I'm on it.