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R34 Gtr V Spec Rear Diffuser - Aero Data

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GTR600 Proficient

GTR600

Posted
Posted

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!

iwanta34gtr Grand Master

iwanta34gtr

Posted
Posted

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) Grand Master

(OO)SKYLINE(OO)

Posted
Posted

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 :D

(OO)SKYLINE(OO) Grand Master

(OO)SKYLINE(OO)

Posted
Posted

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 Mentor

wedge_r34gtr

Posted
Posted (edited)

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 by wedge_r34gtr
DattoP510 Community Regular

DattoP510

Posted
Posted

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) Grand Master

(OO)SKYLINE(OO)

Posted
Posted

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 Mentor

wedge_r34gtr

Posted
Posted (edited)

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

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 by wedge_r34gtr
(OO)SKYLINE(OO) Grand Master

(OO)SKYLINE(OO)

Posted
Posted

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

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 Grand Master

SS8_Gohan

Posted
Posted

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 Grand Master

GTR-N1

Posted
Posted

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

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