THROTTLE BODY ???

[howiefisher]

i am going to put my new trickflow streetburner intakes on but i want to get a new tb should i go 70mm or 75 mm. The intake opening is 75mm but its sound to big for stock heads and cam but i am going to put on 24lb injectors and cobra maf what do you guys think 70mm or 75mm????its 60mm now right 95 5.0L 5spd

 

[5spd GT]

It is not going to hurt your straightline performance, whether you get a 70 or 75mm.

I also believe you are not going to see any gain between the two.

To keep it simplistic, just match it to your intake for now. You may be able to use the 75mm in the future.

FYI, if you just have bolt-ons/exhaust, and things of that nature you do not need 24 lb injectors.

Good Luck!

 

[earleys94gt]

I have always heard that you want the TB to be smaller than your MAF, so as to get a ventri type of air flow. I don't know how critical this is to performance though.

I agree with 5spd GT, on the fact that you will probably not see a huge difference between the two. Personally, I'd go 75mm. That way you don't have to buy another one down the road.

 

[95strokerPSU]

Save you're money. Unless you already have plans to swap the heads and cam in the near future, I'd just use you're stock TB.

 

[Venom351R]

You will get more air flow with you new intake w/ a better throttle body. Its already restricted enough w/ stock heads so dont restrict it more on the other end with a stock TB. Go w/ the 75 you wont hurt anything and if you go w/ aftermarket heads later on your already good in that department.

Just remember no type of combination will get its full effect when its mixed with stock parts. Your new intake wont flow to its potential with stock heads and an aftermarket intake and heads wont work that great with a stock TB. It all works together as one unit.

 

[howiefisher]

thanks for your help guys and yes i am going to get heads hopefully used and a new cam so i will get the 75mm for now a least i wont have to buy another one

 

[Grn92LX]

I'd use the stock tb for now until you upgrade the heads and cam down the road. Then use the 75mm. Unless you have the money burning a hole in your pocket then get the 75mm now.

 

[squeak93]

You can pick up a FRPP polished 75mm Tb and spacer for about 200 bucks....not too shabby and real nice pieces...


Like said above, no need to restrict anymore. Stock tbs are only like 58 or something tiny like that. Open it up and have room to grow later. But 24s are not needed at this point either.

 

[5spd GT]

Stock TB is 60mm for the Sn-95s.

 

[howiefisher]

so the 75mm wont mess with my idle or anything like the mass air flow sensor

 

[greenlantern]

i am going to put my new trickflow streetburner intakes on but i want to get a new tb should i go 70mm or 75 mm. The intake opening is 75mm but its sound to big for stock heads and cam but i am going to put on 24lb injectors and cobra maf what do you guys think 70mm or 75mm????its 60mm now right 95 5.0L 5spd

First off the cobra maf is not calibrated for 24lb injectors, it is actually calibrated for 19lb injectors (same one in your car). Yes the cobra comes with 24lb injectors but its the Cobra computer that compensates for the mass air meters calibration which allows it to be able to run the 24lb injector. If you wanna run the larger injector your going to need to find a mass air meter that is calibrated for that size injector.
As far as throttlebody size I'd go 70mm. IMO the 75 is too big for NA and will hurt low end torque. Im not telling you what I think or read, Im telling you what I know. I have run 65mm ,70mm and 75mm. 65mm would probably be optimal for your setup, but for the sake of not having to buy another throttle body later I would opt for the 70mm. The only way I would go 75mm is if your were planning on a supercharger later. Regardless of what anyone tells you the 70mm will pull harder than the 75mm. Bigger is not always better.

 

[The O.G.]

]i have a 65 with the trickflow street heat
it came when i bought the car

i would buy the 75 if it were me without much worry
how much tourque r you gonna lose

iv seen good numbers with both though and not enough bad for me not to buy a 75mm

70 seems a good size
but hell , trick flow opening is 75 so id go for it

I would save MY money for heads ,cam,intake before I would buy those other things

your almost halfway there already with what your spending

have fun and good luck

 

[howiefisher]

you guys are kinda cofusing me how much will the 75m hurt my low end torque you think the 70mm will be the best even though the trick flow intake is 75mm ??????

 

[Grn92LX]

75 will have zero effect on hurting low end torque.

 

[The O.G.]

you guys are kinda cofusing me how much will the 75m hurt my low end torque you think the 70mm will be the best even though the trick flow intake is 75mm ??????

if it were a diff intake maybe i would get somethin smaller,not that the sreetburner
is huge by any means.

my thinking
pros: tfs intake 75mm opening
75mm throttle body even for later if you decide more cubes,blower,etc
price difference is small if any
dont like, it sell it

cons:maybe you lose some tourqe or repsonse
should you even buy one with your mods?

i would buy a 75 if it were my decision

 

[greenlantern]

you guys are kinda cofusing me how much will the 75m hurt my low end torque you think the 70mm will be the best even though the trick flow intake is 75mm ??????

I don't want to confuse you, the choice is yours. Buy what you like. My point is I have been in your shoes and I remember asking guys on the board which throttlebody to go with. And one thing is for sure, ask 10 people and you'll get 15 different responses. Everyone said buy the 75mm lots of folks beleve bigger is better. I already had a 65mm from my first car. So I went out and bought a 75mm. After putting it on the car ran well and seemed to have a little more breath on the high end, however I noticed an obvious loss on hard acceleration on the street. The jump from 65mm to 75mm made it very obvious. Finally I bit the bullet and found a nice used 70mm on ebay. After putting it on I found it to be a very nice compromise between the two. Now the difference between the 70 and the 75 is not huge but there was a noticeable difference. Do some searches there are tons of articles and threads on this subject. And decide for yourself. To put it in simple terms its all about velocity. How fast does the air come in and fill the cylinder. IMO theres a fine line between just right and too much with any combo. IMO the 70 just delivered a little more velocity and the car pulled a little harder with it than it did with the 75.

 

[5spd GT]

A 70 or 75mm is only going to benifit someone in the straightline, if the area after the throttle body has a larger area than 6.84^2.

If you have 4 square inches of area after the throttle body, you are going to see no gains.

 

[howiefisher]

so if i get the 70mm i wont resrtict the intake right its 75mm

 

[ProKiller]

you'll be fine with the 70mm. the opening is there if you need it. but since your still running stock heads, you don't need to optimize your combo to the max by port matching everything.

if your planning on putting some decent size heads on there, it wouldn't be a bad idea to get the 75mm, but i wouldn't put it on until you put the heads/cam in. the stock tb won't kill you at the moment.

 

[Grn92LX]

so if i get the 70mm i wont resrtict the intake right its 75mm

Use the 75 if you're going to upgrade. If not keep the stock one. Match the tb to the inlet if you're upgrading. Pretty easy stuff here.