Tuning

[NZAE92]

Hi everyone
i am looking into getting my carb tuned to the headers and exhaust that has recently been put onto my car.
I'm going to go to a professional and let them do it. I called a few places up and the prices varied from $40-80 to get it onto a gas analyser and have the fuel/air mixture changed.

I was just wondering will the carb need bigger jets if i want more power or will the jets be sweet like they are and the fuel/air mixture just need to be fiddled around with.
any help would be great
Cheers
Greg

[eage8]

I may be wrong but I'm pretty sure the mixture screws really only affect idle. the jets are the things that control the mixture underload. it'll depend on how it's tuned stock whether you need new ones or not.

Do you have a weber? I'm not sure if the stock carb is re-jetable...

[Flashmn]

I may be wrong but I'm pretty sure the mixture screws really only affect idle.

Setting it would most likely affect the progression to the main jet a bit aswell, but its mostly idle mixture and idle speed you set with the screws in the back of the carb. Good luck getting jets for the toyota carb, its really one of those never-fix items (you cant even get diaphragms for them) and expect to pay some money if they have to drill and test different sizes.

The stock jetting isnt going to be affected much by the header and exhaust, mine sure wasnt...

[NZAE92]

over the phone it sounded like the guy knew that you could rejet it,pricing is around $120 NZD for bigger jets, but i can't be too sure.

one of the guys i had called up said something about boring them out or replacing them with new ones or bigger ones???
i don't want anything drilled but if that's how you get them out then fine, and will having bigger jets do anything with the power??

oh and eage8 no i don't have a weber i wish though. who was selling one on here again for the 4af engine. someone on here was but i can't remember.

[Flashmn]

They'll drop your mileage, I think the 4A-F runs relatively rich compared to the 4A-FE...Drilling the jets is fine, although its pretty much a one way street. (you can solder them if you drill them too big and then redrill them smaller, but I dont like that method)...

[NZAE92]

Adding more fuel and more air will increase power right??
that's what i'm wanting.
i do run it on 98 with ethanol and it is expensive 1.87 for a litre but at the supermarket that i go to 4cent off vouchers are given out when you spend $40 or more so that helps. mileage doesn't bother me it is low as it is anyway with headers and exhaust, but if i don't drive it hard it should be sweet.

[Flashmn]

No not necessarily, if it gets too rich power will drop.

[NZAE92]

ok thats good to know
thanks for everyones help
i do really appreciate it

[eage8]

Originally Posted by NZAE92

oh and eage8 no i don't have a weber i wish though. who was selling one on here again for the 4af engine. someone on here was but i can't remember.

That is me. but it's currently pending sale. I'll let you know if it falls through if you're still interested.

most people get more power by actually leaning out the fuel mixture and increasing ignition advance. more fuel won't make you any more power. the weber actually has bigger throttle plates so it can let more air in with more fuel to make more power.

[canadianae92]

you should go with a weber setup if you plan on modifying that motor more, i dont think the stock carburetor has much to give you

[Evo_lucian]

jet or carb upgrade on a 4af for exhaust and headers is a waste of time IMO. The costs will severely out weigh the gains

[NZAE92]

ok so im not going to be getting them done after all your good feedback.
is it hard to fit that weber that you have eage8. how much are you wanting for it if it doesn't fall through?? and how much to send to new zealand? hahaha. cause carb kits are expensive here and hard to find.