throttle body ?

87WhiteStang1

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Dec 19, 2007
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i have and 87 mustang gt with exhaust intake underdrive pulleys...i was thinking about getting a 70mm throttle body. i wanted to know if this would really make much difference in power and if it would make much difference in gas usage? let me know if you have experience
 
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For that set up, No more than 65mm........ Going larger will just bog it down, You'll lose low end.

i have and 87 mustang gt with exhaust intake underdrive pulleys...i was thinking about getting a 70mm throttle body. i wanted to know if this would really make much difference in power and if it would make much difference in gas usage? let me know if you have experience
 
For that set up, No more than 65mm........ Going larger will just bog it down, You'll lose low end.

That's an old myth. Its not a carburetor. So long as you grind the intake opening to match, you can go as BIG as you want. With that said, I would shoot for 70mm. You won't realize its full potential until you do H/C/I, etc, but at least you'll have the room to grow. I'd guess that you'll see 5-10 HP with no other changes.
 
i have richard holdeners 5.0 dyno tests book. he compared a stock engine with the stock 60 mm vs a ford 65mm. the 65 made like 2 more rwhp peak. under 4k the curves practically layed right ontop of each other.

i say dont bother man. especially with a 70. you have to mod these engines from the inside out. You will not even come close to feeling a 2 rwhp difference. you can get more than that from a cold day vs a hot day, or doing a tuneup.

JMO
 
appreciate the advice...however i do want to do something to get just a bit more power. ive got the full exhaust..underdrive pulleys..intake..for racing plugs n wires.. i dont know what else i can do ( as far as small things ) to get a little bit more power... any suggestions would be great !
 
By "intake", do you mean cold air intake?

I still say TB is a good starting point. Yea, you won't see much right now, but its something that will shine with further modifications. It also makes sense to do that before you go swapping heads or intake manifold.

As a side note, DON'T touch the cam until the rest of the motor is built. That is a mistake a lot of people make. The stock cam is very capable of making decent power.

You could spend a little more and do rear end gears, that's always a good go-fast mod.

Another idea, and something I did early on, was convert to electric radiator fan. I can't say for sure, but people claim it reduces parasitic drag the clutch fan would make. Worth power? Maybe. Will it help the car run cooler and clean up the engine bay? Yep.
 
+1 on the gears, while it isn't a hp mod the gears will get the car moving quicker of the line and makes the revs more useful persay, improves your 0-60 and 1/4 times. 3.55's or 3.73's are a good choice for a T5 car most guys will swap in 4.10's on a AOD car.

swapping in a 94-95 V6 or V8(not cobra) or a 92-94 crown vic, marc or town car with a 4.6's 70mm MAF is a plug and play set up for the 19lb injectors and is better than the stock 55mm maf, it's better to be at or bigger than the TB, also a bump in timing wakes the motor up, go 2 degrees at a time from the stock 10 until it pings and then back it down 2, run some premium fuel. I would probally stay around 14BTDC for the street though but your motor will tell you. A strut tower brace, 4 point K brace, and subframe connectors should def be on your list to tighten up the floppy chassis. down the road a 3g alt upgrade would be a good idea, best of luck.
 
OK...so if i wanted to get gears i need some recomendations... i would probably do 3.73s or 3.55s ... i want something that i can feel a difference with and also something that i cant tell to much of a difference with at the pump...i drive the car about every other day or so...also if i got the gears then would it be a good idea to get the TB? i dont plan on swapping heads or cam or intake manifold. Let me know guys...THANKS
 
I'd say 3.55's for a daily or frequent driver. Having no first gear gets old. I've got 3.73's in my car and I'm switching to 3.55s, since I'm going to be rebuilding the rear end anyway.

With the tb, you'll need to eventually get a larger maf so that your whole intake track is larger. Al Kirschenbaum in his 5.0 book recommends a slightly larger MAF to tb ratio. I went with a C&L 73mm to go with my 70mm tb. When I replaced my stock 5.0 pieces with that, it was like :eek::nice::rock: Of course I have Explorer intake and heads, so the stock stuff was choking my combo.
 
Stock is 60mm. Go with a 70mm and make sure you file out or "hog" out the intake opening to match the throttle body. You will notice more from your mods if the car had Mass Air though.
 
OK...so if i wanted to get gears i need some recomendations... i would probably do 3.73s or 3.55s ... i want something that i can feel a difference with and also something that i cant tell to much of a difference with at the pump...i drive the car about every other day or so...also if i got the gears then would it be a good idea to get the TB? i dont plan on swapping heads or cam or intake manifold. Let me know guys...THANKS


Anyone who tells you that your gas mileage isn't affected much is incorrect. They will hurt your mileage but you have to pay to play. You will get a slew of opinions so let me give you mine first as I've had both...

3.55- Perfect for an everday driver. The difference in my car was almost 2/10 of a second but I went from 2.73's. You can use 5th gear at 50mph and not have to downshift to 4th so much. On the highway they rock. This is the gear I recommend. Not bad at all in the rain either unless you're on a big hill on wet pavement, then start out of 2nd gear!

3.73- Rough and tough. Not much more of a difference but it was noticable to me. Really not a bad choice and not much different from the 3.55's. Very much a kick in the pants. I prefer the extra rpm (tho it is a small bit) that you get in the 3.55's on the highway.


I wouldn't go any higher. Also there is a little plastic gear you can get from ford and possible the internet. It replaces the speedometer gear in the left side of your t-5. Just follow the speedo cable and loosen the nut. Replace and it will make your speedometer read much more accurately.


Good luck man you will love them much more than any old throttle body. Thank us later :nice:
 
A 70mm throttle body on a car with a stock intake manifold and a stock MAF meter is a complete and total waste of time and money. The stock throttle body is not creating any restriction in your set-up right now. The lower intake manifold and heads are what are holding you back. Either put your money towards a better manifold (or have your existing one ported) or heads, or do as others have suggested and put the money towards gears.

Again, for you a throttle body by itself is a complete and total waste of time and money with your set-up.