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its been covered once before but no harm in bringing it up again

engine is rb30 (not sure if extra height makes a diff)

chassis is r33 gts

current setup is ITS T66 with 0.7 comp

snug fit, room for a bit more

i want to go atleast gt35, preferablily gt40 and still use the low mount setup

i need pics of what turbo your using pls and its fitment

thanks

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its been covered once before but no harm in bringing it up again

engine is rb30 (not sure if extra height makes a diff)

chassis is r33 gts

current setup is ITS T66 with 0.7 comp

snug fit, room for a bit more

i want to go atleast gt35, preferablily gt40 and still use the low mount setup

i need pics of what turbo your using pls and its fitment

thanks

If ITS is anything like Garrett, a T66 is bigger than a GT35R - so you will be downgrading if you went to a GT35R. A Garrett T04Z will fit in that location though I wouldn't be too sure a GT40R would.

If you mean the HKS low mount cast split pulse manifold with the external gate mount on top there are interesting possibilities .

If you look at the turbo mounting "pad" you'll see that it's big enough for the full sized T04/TA45 foot print , HKS used the smaller split T3 (correctly speaking T4 Euro) stud pattern and twin outlets .

I used to have pics of one of these manifolds redrilled/tapped and ported for the large T4 type turbine housing footprint .

Your call but I would be wary of using huge turbos on RB25's, would work better on a 25/30 but not really a race type valve train .

HKS also did one for RB26 heads and they were big T4 flanged and intended for a bigish dinosaur TA45S . The modern equal turbo wise would probably be a GT4088R .

A .

If you look at the turbo mounting "pad" you'll see that it's big enough for the full sized T04/TA45 foot print , HKS used the smaller split T3 (correctly speaking T4 Euro) stud pattern and twin outlets .

I used to have pics of one of these manifolds redrilled/tapped and ported for the large T4 type turbine housing footprint .

Mine has the 'dual' drilled and tapped positions. I used the T3 and a GT3076 WG [popular choice for many]. And yes, in theory you could use the T4 footprint for a bigger turbo, but tI wouldn't like to port match the T4 footprint to the turbo [assuming the T4 has a larger throat]. To do that I would guess you'd firstly have to build up the outside with cast weld to strengthen and thicken the metal.

If you didn't do this I'm estimating/guessing you'd almost certainly break out, or thin the metal that much it would be too weak and fracture/burn away.

By the way, the limiting factor isn't the turbo size, there is plenty of room all round, its the turbo inlet size. I have a 100mm unit and had to cut back the front engine mount for clearance. I actually thought of refacing the mounting position ie cut the T3 mounting face back at an angle [say 5 degree's], this would swing the turbo mouth out a bit, but then you have the stud holes, so you would have to weld them up and retap square to the new face etc. I don't think this would have affected flow, the manifold casting [tubing] is still at a slight angle as it drops to the T3 face - but then I got lazy and left it. Now its on and I CBF, its working, I'm driving, thats it.

If you mean the HKS low mount cast split pulse manifold with the external gate mount on top there are interesting possibilities .

If you look at the turbo mounting "pad" you'll see that it's big enough for the full sized T04/TA45 foot print , HKS used the smaller split T3 (correctly speaking T4 Euro) stud pattern and twin outlets .

I used to have pics of one of these manifolds redrilled/tapped and ported for the large T4 type turbine housing footprint .

Your call but I would be wary of using huge turbos on RB25's, would work better on a 25/30 but not really a race type valve train .

HKS also did one for RB26 heads and they were big T4 flanged and intended for a bigish dinosaur TA45S . The modern equal turbo wise would probably be a GT4088R .

A .

I have the same HKS manifold & gate as mentioned with Garret T04E turbo, it is quite a tight fit that the engine mounting had to be modified using RB20 engine mounts with spacer plates to match the height. Any chance the T04Z would fit, cos i really like that turbo. Not interested to go top mount cos heard that they do crack due to the weight.

I have the same HKS manifold & gate as mentioned with Garret T04E turbo, it is quite a tight fit that the engine mounting had to be modified using RB20 engine mounts with spacer plates to match the height. Any chance the T04Z would fit, cos i really like that turbo. Not interested to go top mount cos heard that they do crack due to the weight.

Poor Quality Stainless Steel High mount Manifolds will crack.

Good quality Stainless ones are not as likely to crack if setup correctly.

Steam pipe manifolds ie. ETM/6BOOST are preety much guaranteed not to crack and will probably flow alot better than any of the lowmount style manifolds

Trident I had a feeling the HKS cast manifolds port sizing would be the limiting factor .

HKS would have known that and gone straight to the real T4 flange/port dimensions on the RB26 spec single turbo split pulse low mount manifold . The one I looked at certainly looked like it meant business anyway .

A while back FullRace Geoff did mention a power figure at which the T4 Euro split port flange size (commonly known as "split T3") becomes a restriction . The ports through this smaller flange can only be made so big and eventually with enough exhaust flow becomes limiting - regardless of what A/R housing or turbo is bolted to it .

Don't forget that most Garrett T4 (Euro or the larger "T4 International" type) housings are made for Diseasils which have lower EGT's and are usually low reving things .

Garrett only went as far as the GT3582R and the "T3" footprint , their marketed version of the T04Z (same cartridge as HKS units) can arguably use split Euro or split International T4 flanged housings but really they are intended for diesels . The T04Z cartridge is a modified P trim/60-1 cartridge - uses the BCI-8D (T04R) compressor wheel .

Note HKS used a split T4 International flanged turbine housing that merges into one volute passage .

I think a GT3582R in its largest A/R turbine housing (1.06) should be able to go to the limit of that HKS RB20/25 cast manifold .

A .

Poor Quality Stainless Steel High mount Manifolds will crack.

Good quality Stainless ones are not as likely to crack if setup correctly.

Steam pipe manifolds ie. ETM/6BOOST are preety much guaranteed not to crack and will probably flow alot better than any of the lowmount style manifolds

A friend 34GTR with high mount T67 Trust kit had leaks due to cracks in the manifold. not sure which part but he eventually fabricated a totally new using better material stainless and much thicker too. Though the weight now is pretty heavy.

  • 1 month later...
  • 9 years later...

Hello, I know this is a major resurrection of a thread, but does anyone have any new experiences with ow mounting big singles. I see hypertune has a big low mounted single in their S15, and the RIPS R34 borg has a medium sized low mount turbo. Im interested in low mounting an EFR 8374, but cant seem to find much info on people low mounting big singles.

Low mounting a 8374 is lol. It is a huge turbo, in the context of low mounting one in a RB.


My 7670 was much, much, much larger than a GTX3582 and that was a squeeze to low mount. (The GTX3582, the 7670 low mounting was a non-option)

The answer on low mounting a single nowdays would have to be the Garrett G series - They are much more compact for the power they put out. Definitely 100% without any doubt ever that is the turbo you want to get if for some reason you demand it to be low mounted.

Thanks man, I should divulge that my car is not a skyline or an S chassis, so I may have more room to work with.. Id really like to see your low mounted gt35 if you were willing to send me a picture. As much as id like to try the G series, I cant seem to find any info on them, which is surprising. I figured of all people, the GTR guys would be all over these. I dont know what they compare to in size to previous Garrets, and I am unsure of what they compare too in response/spool on a 2.6 RB. The output is plenty im sure. 

19 minutes ago, Kinkstaah said:

Low mounting a 8374 is lol. It is a huge turbo, in the context of low mounting one in a RB.


My 7670 was much, much, much larger than a GTX3582 and that was a squeeze to low mount. (The GTX3582, the 7670 low mounting was a non-option)

The answer on low mounting a single nowdays would have to be the Garrett G series - They are much more compact for the power they put out. Definitely 100% without any doubt ever that is the turbo you want to get if for some reason you demand it to be low mounted.

 

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Edited by DiscardTheWeak
Just now, iruvyouskyrine said:

Are you specifically using the cast HKS low mount?

I have a custom low mount manifold made that currently runs an EFR6758 but fits an EFR 8374/9180 with ease in my RB20 S15.

No, I am not using the HKS manifold. I would very much appreciate pictures of your setup, as it would help alot. The 6758 and 8374/9180 are quite different in size. Id even be interested in who made your manifold, would save me the trouble of making one. Thanks

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