R34 Gtr V Spec Rear Diffuser - Aero Data

[GTR600]

All,

Does anyone have any test data (aero mainly) relating to the rear diffuser on a R34 GTR V Spec? Obveriously it does assist in some way (Nissan would not of manufactured a carbon sheet for nothing - I don't think!), but at what speeds and how?

Has anyone ever driven without their rear diffuser and noticed any differences?

Wondering if it is worthwhile removing as even though its carbon - it does add to the weight of the car and may not assist on the type of tracks I drive on (opposed to others - ie Nurburgring (High speed track)

Thanks guys!

[GTRsean]

Z tune doesn't have one fitted.....

[INLINE6]

If you remove it I will buy it. LOL.

[GTRsean]

Roughly $7000 from nissan new......anyone would buy it!!!!!

[INLINE6]

Hahaha ahh shhhhh Sean! I got dibs. LOL.

[GTRsean]

LOL!!! grab a set of brackets too then Dave!!

[kimbod]

I know it stops the back of my car getting exhaust residue all over it.

[iwanta34gtr]

I've driven mine without the diffuser previously, didnt notice any difference.

I actually have access to a replacement genuine Nissan rear carbon diffuser, still in excellent condition, if anybody is keen - shoot me a PM with an offer.

[(OO)SKYLINE(OO)]

All,

Does anyone have any test data (aero mainly) relating to the rear diffuser on a R34 GTR V Spec? Obveriously it does assist in some way (Nissan would not of manufactured a carbon sheet for nothing - I don't think!), but at what speeds and how?

Has anyone ever driven without their rear diffuser and noticed any differences?

Wondering if it is worthwhile removing as even though its carbon - it does add to the weight of the car and may not assist on the type of tracks I drive on (opposed to others - ie Nurburgring (High speed track)

Thanks guys!

Rear diffuser is for aero dynamic purposes as it keeps air flowing smoothly under the car.

You'd would probably only notice it on a track, (down the straights) going speeds above 100km/h or while you are speeding up on to an on ramp to a free / highway.

Z tune doesn't have one fitted.....

Because of rear diff oil coolers

[wedge_r34gtr]

Because of rear diff oil coolers

Did the UK spec cars still have them fitted from factory?

I have seen some custom ones where they made NACA style ducts for the diff and transmission coolers.

[(OO)SKYLINE(OO)]

Did the UK spec cars still have them fitted from factory?

I believe rear diff oil coolers are a R34 GTR Nismo Z-Tune item only.

But there is no stopping owners from putting a rear diff oil cooler on, a non Nismo Z-Tune.

I have seen some custom ones where they made NACA style ducts for the diff and transmission coolers.

Pics?

[wedge_r34gtr]

I believe rear diff oil coolers are a R34 GTR Nismo Z-Tune item only.

But there is no stopping owners from putting a rear diff oil cooler on, a non Nismo Z-Tune.

Pics?

The uk delivered cars definatly had additional coolers at the rear. I'm unsure if these were the same as the ones fitted to the the Z-tune (doubt it)

I'll have a search after i finsih work and see what i come up with regarding the diffuser

Edited July 25, 2012 by wedge_r34gtr

[DattoP510]

_{keen to hear if anyone has any data on this. I have fitted V spec diffusers to my non v spec 34 to improve high speed stabilty and reduce drag. I have significantly improved lap times with them fitted but hard to isolate the aero effect as i have made other mods and gained experience aswell.}

[(OO)SKYLINE(OO)]

The uk delivered cars definatly had additional coolers at the rear. I'm unsure if these were the same as the ones fitted to the the Z-tune (doubt it)

I'll have a search after i finsih work and see what i come up with regarding the diffuser

Yeah sure, thanks

I do know the UK models did come with a few extras here and there but didn't know about the rear diff oil coolers.

But will be interested to know.

[wedge_r34gtr]

Couldn't find the thread that detailed the custom diffuser (pretty sure it was for a big $$$ build on SAU too )

but the uk cars deffinatly had a transmission and a diff cooler mounted under the the diffuser. If you have a copy of the skyline story, you can see em when they put the uk car on the hoist.

I did note that the standard r34 diffuser has a duct to cool the rear diff...didn't really think of it till i saw a pic...so it wouldn't be that difficult to duplicate on a custom one to feed air to an oil cooler.

just of note aswell, one of the additional features listed about the Z-tune is "Z-Tune Dry Carbon Diffuser with 2.2 times more downforce than normal GTR ". Not sure if this is refering to the front diffuser, as i couldn't find any clear pics of a confirmed Z-tune that had a rear diffuser.

Edited July 25, 2012 by wedge_r34gtr

[(OO)SKYLINE(OO)]

Couldn't find the thread that detailed the custom diffuser (pretty sure it was for a big $$$ build on SAU too )

but the uk cars deffinatly had a transmission and a diff cooler mounted under the the diffuser. If you have a copy of the skyline story, you can see em when they put the uk car on the hoist.

I did note that the standard r34 diffuser has a duct to cool the rear diff...didn't really think of it till i saw a pic...so it wouldn't be that difficult to duplicate on a custom one to feed air to an oil cooler.

Ah yeah, found it on Wiki:

"The V-Spec version was also imported into the UK with a number of modifications carried out on the car. These included 3 additional oil coolers..."

But thanks

just of note aswell, one of the additional features listed about the Z-tune is "Z-Tune Dry Carbon Diffuser with 2.2 times more downforce than normal GTR ". Not sure if this is refering to the front diffuser, as i couldn't find any clear pics of a confirmed Z-tune that had a rear diffuser.

Would be the front as the is no rear diffuser on the Z-Tune.

[SS8_Gohan]

i put one on my previous GT-T and there is an easily noticeable difference at high speeds. Cruising around, nothing, but at 80-100km/hr+ you could definitely feel the car was more stable. Even my gf sitting in the passenger seat noticed it and she a) didn't know it was on b) i hadn't even told her i put it on. Maybe it's a bigger difference to a lighter GT-T, but you could definitely tell the difference.

there are naca ducts in the standard diffusers.

as for the Z-Tune diffuser having 2.2 times more downforce..... that's relating to the front - diffusers can be front and rear. The front Z-Tune diffuser is mix of CF and magnesium... looks sex, can't buy em though unless you're a Z-Tune owner (or know one i guess) - hate to think how much they are...

[GTR-N1]

Maybe we should try and organise a Tech Night on wind tunnel testing, -ve pressure below underbody diffusers, rear wing blade settings, height of stems, canards, NACA ducts, scoops and cd/wind resistance

[SS8_Gohan]

like a Uni wind tunnel or something? surely would be hideously expensive to hire? unless we can make it a "project" for some uni student

[Owgasm]

Monash

THE FSAE team uses one every so often, see if any of them want to do it or share hire