Throttle boddies

[IceBlade]

Now im thinking about upgrading my throttle body, and im looking for the opinions of you the sxoc....
what are the pro's and con's (if any) of getting a bigger throttle body and is there anything bad about using big throttle body, as in is there any limit to how big you can go etc?
thanks guys
joe

[xR33]

Not 100% sure if it's worth doing the S13 throttle body unless you're running big power? I did on my S14 (used a Nissan P11 one IIRC) as the throttle on the SRs are tiny, but even then it wasn't a huge change in delivery.....

Edit - SR20 is 50mm, CA18 is 65mm.....

[STR8E180]

S13 SR20 engines
SR20DE non vct throttle body = 60mm
SR20DET non vct throttle body = 60mm

S14 and S15
SR20DE vct sr20 = 60mm
SR20DET vct sr20 = 50mm

only the S14/S15 SR20DET vct sr20s have the smaller throttle bodys so the non turbo sr20de vct throttle bodys are a good upgrade
the non vct sr20 throttle bodys from the S13 sr20s will bolt onto the plenum but the throttle cable linkage is different as well as all the water pipes and sensors so ur better of with a non turbo throttle body from a S14 or S15 if ur looking at upgrading on a S14 or S15 turbo engine

we have also done some testing with response with throttle bodys as well

copied and pasted from http://hardtuned.net/forums/index.ph...ic=382765&st=0

done some testing with the N/A 60mm SR20DE throttle body and this is wat we found out

with the standard cam shafts the standard SR20DET 50mm throttle body works better (which is why the 60mm throttle body was swapped back for the smaller 50mm)
the standard 50mm throttle body is more responsive and also gives more mid range power (only with standard cam shafts) BUT once u get to 6000rpm it starts to struggle to rev any higher, u notice the engine not being able to rev as fast and as free from 6000rpm to 7300rpm which is wat the rev limiter is set on
the 50mm throttle body just doesnt breath good enuff from 6000rpm to allow the ports to flow enuff air

with the SR20DE 60mm throttle body we noticed it wasnt as responsive and we lost power in the mid range compared to the smaller 50mm throttle body but we noticed the engine would rev easy all the way to the rev limiter once we reached 6000rpm it would continue to rev to the rev limiter with out struggling basically it would jump str8 to the rev limiter

so if u are still using standard cam shafts the 50mm throttle body actually works better which is why we swapped the 60mm throttle body for the smaller 50mm throttle body
once we upgrade cam shafts the 60mm throttle body will be put back on because the 50mm throttle body will become restrictive but at this point in time with the standard cam shafts the 50mm throttle body works better

can u let me know how much power ur aiming for and wat mods u got/planing
its hard to offer advice with out knowing much about ur setup

also for those who wanted to see the car tuned on 98octane we have done that for u all
the car made 260rwkw with standard cam shafts i'll post up the dyno sheet for u guys/girls 2morrow

[IceBlade]

Forgot to mention im running a CA18DET so i think its 60mm as standard, but im looking to be upgrading the cams and throttle body and have 3 inch IC pipework so i was thinking maybe a 3 inch (75mm) throttle body would be optimal
just looking for peoples views or experiences to aid my choice, like will a massive throttle body be bad for general drivability etc

[STR8E180]

y do people run such big intercooler piping ur just causing more pressure drop which results in less response
i wouldnt use 3inch piping unless i was building a insane drag car
2.5inch piping is more then enuff for most road cars

are u thinking about putting a 75mm throttle body on a standard CA plenum???
wat turbo u using??? and wat power are u aiming for

[IceBlade]

£ inch piping was a bargain when i started looking at FMIC's just kept it ever since, standard CA plenum at the moment yes, im using a t3/t4 hybrid at the moment good for about 450bhp, not really aiming for a certain figure, just love tinkering with my nistune kit and want to know what benefits/drawbacks i would get from a bigger throttle body

[STR8E180]

well a 75mm throttle body on a standard CA plenum is going to be pretty point less
i dont even think ur going to be able to machine out the inlet of the plenum that big

i machined out a standard SR20 plenum to 70mm and thats the biggest i could go other wise i would of taken away to much metal

this is a picture of a 70mm throttle body gasket placed ontop of a standard plenum
as u can see the plenum had to be machined open to suit the bigger throttle body i wouldnt recommend machining any more then that


for ur car i wouldnt go any bigger then 70mm, theres no way ur going to max out a 70mm throttle body
try get ur hands on a N15 pulsar throttle body or a XF falcon throttle body they are both 70mm, both use bosch sensors and they are also both 4 bolt flanges this is important for throttle bodys being used on turbo charged engines

[IceBlade]

thanks for the info bud, what efect does bigger throttle body have on general driving? are there any drawbacks?

[STR8E180]

thanks for the info bud, what efect does bigger throttle body have on general driving? are there any drawbacks?

we noticed on our S14 with standard cams the smaller throttle body was more responsive but didnt have as much top end
when we installed a bigger throttle body it wasnt as responsive and we noticed it while driving put it on the dyno and saw it on the dyno but it had more top end
we ended up putting the smaller throttle body back on because we were more after response

i personally think ur have gone to big with ur intercooler piping so u already have big pressure drop due to ur piping size so dont think ur gonna notice any more lag
i like to keep piping the same size as the throttle body (or just slightly smaller) and the same size as the turbo compressor out let
there is no point going overly big when ur engine cant flow that amount of air and ur turbo cant push that amount of air
causing pressure drop for no reason

[IceBlade]

i see..... shame it wasnt 2.5 inch piping that came up cheap then, i currently dont get 10psi till just over 4k 4300rpm maybe

[liquidsmoke]

iceblade. I want that CA sticker...where where where?

[IceBlade]

found on ebay bud ,type in ca18det
http://cgi.ebay.co.uk/CA18-CA18DET-1...d=p3286.c0.m14

[xR33]

STR8E180 - All the intercooler kits sold over here have 3" pipework I think .

[STR8E180]

STR8E180 - All the intercooler kits sold over here have 3" pipework I think .

well 3inch is way to big for intercooler piping on a street car
the only pipe i would use 3inch piping is if i was building a drag car
2.5inch is as big as i would go on a street car, circuit car, drift car

[FIGJAM]

I've got a Q45 80mm (not 90 as many think) but thats for a high reving solid lifter engine with PNT plenum.

There is no doubt it impacts drivaliblity. Its great for top but I wouldnt put it on a daily driver, if you want to do track work etc then go bigger but Q45 is too big unless your building a massive power car.

Q45 looks amazing though!!!!!

[meminto]

I have an australian XF Falcon throttebody on mine - 73mm in diameter... on a PNT plenum too lol





Not as big as the Q45 one above, but I didn't have a requirement for something of that size.. it dwarfs the stock one in that photo lol...

[Vetal]

Slightly off topic, but how do you like your PNT manifolds? They are more or less affordable, I might want one for my CA18

[R3K1355]

Slightly off topic??

The topics 3 years old FFS, half the people who've posted probably don't own S-bodies anymore.

[Vetal]

Well, some knowledge must be kept for longer than a couple of years )) that's how civilization works

[M.D.]

lol.
even more off topic, there has to be a grands worth of aeroquip fittings in that inlet pic!!!!