What Will Happen If I.....

[spoolin25psi]

Christmas is almost here and i wouldnt mind getting a throttle body. if i ask santa for a 75mm throttle body and egr spacer how would it effect my 87 5.0 mustang? mods include (not much)
ported heads, 1 3/4 long tubes, and under drive pulleys, next week im installing an f-303 cam, ford racing hardened push rods, and roller rockers

if this throttle body is overkill, what size throttle body should i get?
thanks and Happy Holidays :SNSign:

 

[srothfuss]

Is your car still SD? if so, the cam swap (although not impossilbe) is not recommended. Swapping heads, Intake and exhaust will be OK but the cam will cause vacuum problems.

For a N/A car, 65mm throttle body is probably all you will need. 75 is fine if you have future plans for an S/C or Tubro/

 

[Euphoric306]

yea, i would think an f-cam is a bit overkill for a stock maf engine as well? i might be mistaken

 

[jrichker]

Another vote for the 65 MM TB.

 

[bynummustang]

My mods are in the sig. and I just put RPM upper and lower on, the car ran sluggish with a 70, went back to the 65 and hauls ass. Broke tires loose in 4th...

 

[spoolin25psi]

well i learnt alot, i think i will go with 65mm, thanks guys!!! ooh 2 quick questions, how big is a stock throttle body? and what do you think of a b cam instead of the f cam? thanks again

 

[bynummustang]

stock is 60 I think. B cam is decent, I have the stock cam and it still does the job.

 

[srothfuss]

But is your car SD still? (speed density?) 1987 - 1998 5.0L motors were sent from the factory with an SD system. Changing the cam can cause serious problems unless you use a SD friendly cam or convert to a MAF style system.

 

[fordguy87]

I'm his cousin, he forgot to say that hes converting to mass air in the process of all this.

 

[Grn92LX]

That 75mm throttle body will be fine if your manifold inlet is 75mm. If its not, you'll need to port match it with a dremel. I switched from a tiny 65mm tb to a 75mm on my old n/a 302 as recommended by my cam grinder (Ed Curtis) Nope, it did NOT hurt my low end.

 

[gt40_2003wes]

go with the 65 unless u plan on some serious future mods.

 

[Deleted member 87397]

Do one thing at a time. i.e do the maf conversion before you do anything else and get it running right before you tear it down for the rest of the work. There's nothing worse than doing a bunch of things at once and then having to troubleshoot everything to figure out one glitch. Just my .02

 

[olong_us]

im also one of spoolin25psi buddies. I want to know if the stock E7 heads can take the lift of the b cam, and if the springs r ok and wont bind. Thanks Alex

 

[Grn92LX]

im also one of spoolin25psi buddies. I want to know if the stock E7 heads can take the lift of the b cam, and if the springs r ok and wont bind. Thanks Alex

Springs will NEED to be changed. Have the heads clean up milled to ensure they're straight, change the valve seals and look into grinding down the egr bump in the exhaust port.

 

[Black-Fifty]

I dont know most people think that the bigger the TB the better performance, trust me you will be more hurting your car than helping it. Just go with a 65, or save some more of you money and get a intake system or full exaust.

 

[TheUser]

I've got a book w/ dyno pulls of several combinations. In it, it has a TB test and bigger is not always better. I think you'd be best suited with a 65mm TB as well unless you plan on going w/ a power adder in the near future.

I've posted those dyno numbers in several other threads of this sort and I can do so in this one as well if you want.

 

[gcwh02]

srothfuss you mean 1987-88, not 1998 right?

 

[srothfuss]

srothfuss you mean 1987-88, not 1998 right?

Opps, yeah that was a type-o.

 

[RDF 01]

That t.b. would be way too big, you would loose power for sure, I'm running GT-40 intake & heads E/ cam, 73mm maf & complete exhaust on my '88, and I think my 70mm is too big- I felt a noticeable loss in low rpm power. You're better off buying a good MAF, thats the bottleneck.

 

[RDF 01]

Is your car still SD? if so, the cam swap (although not impossilbe) is not recommended. Swapping heads, Intake and exhaust will be OK but the cam will cause vacuum problems.

For a N/A car, 65mm throttle body is probably all you will need. 75 is fine if you have future plans for an S/C or Tubro/

I can vouch for this first hand, I did the E/cam and GT-40 heads on my 88 SD and the car would not idle at all, ran bad and was a hard start, so I had to change to mass air. You should leave the cam alone and do intake & exhaust- maybe even 1.7 rockers. I've heard of lots of people running very fast w/SD & stock cam, it's a good system, but does'nt like cams. Sorry, I figured you had a mass air car- woops.