Got A 3076r - Just A Conclusion

[WYTSKY]

Thanks Lithium, been a long time coming

oh my, good work on the turbo upgrade adam, you're car is gonna be heaps crazy!

are you still planning to keep the bottom end DE or are you in the process of rebuilding it as we speak?

hey mate, no im still gonna have the N/A bottom and top end for now... hence, the not too much psi or kilowatts for now, I just had a few issues with internal gate, so want to go external.

I may think about the gate on the housing.... its just... it looks so pretty right now... plus if it cracks then im guessing it could ruin the turbo too?

Cheers,

Adam

[discopotato03]

You raise some very valid points Lithium but as always people have financial limits and hopefully realistic goals for mostly street driven cars .

For the money I think a 1.06 AR integral gate GT3076R would be pretty good on a reasonably warmed over RB30 twin cam . I think you could use the factory exhaust manifold and with a little head work and mild cams and have a reasonably linear six that felt like a 5+ liter v8 .

The T3 flange footprint has only so much real estate and if you plant a divider in the middle of it a bit less .

What I am saying is that a really flying Rb25 and a GT3076R can probably just about run to the limit of an open collector type T3 flange , not be too laggy and feel more than adequate in the sink you back in the seat stakes .

LOL : TO BE CONTINUED Domestic bliss for a lil while .

A .

[discopotato03]

A bit more . I think once you go to three liters there isn't the low down torque requirement because you have the extra 20% capacity to get around the burbs well enough .

If you are looking for super power from an RB30 twin cam then it has to be able to breathe and rev and if it can't exhale easily then it will find its ceiling prematurely IMO . There has to be enough exhaust gas capacity to cater for a 3 liter engine that suddenly wants to exhale like a 6 or 7 liter one and I can't see the largest particle split T3 flange ports handling the gas flow without a significant pressure rise in the exhaust tract .

HKS has been around for a while now and have lots of bits for high revving high powered RB26 engines . Take their single low mount cast iron manifold as an example , T4 TS flanged for the TA45S that went with it .

The T04Z kits they do are also made with the TS T4 footprint , even though those turbine housings are not really twin scroll .

Really all the big frame ball bearing Garrett's (T04Z/GT4088R/GT4094R/GT42R/T51R etc) are designed to use T4 flanged turbine housings and the only reason why T3 flanged housings can be fitted to T04Z's in because T4 P trim turbines and housings have been around for some decades in the diesel world . Plenty of early T04 turbos had little T04B series 71mm compressors on them and they at times used single and twin entry turbine housings with T3 flanges . Actually I think some people used to call the twin entry "T3" flange T4 Euro and its actually a little wider across the twin inlets than a true T3 single entry housing .

Cubes here had pics posted of how he did a bit of porting on his GT30 turbine housing to try and make it match his RB exhaust manifold .

For a cheapest way out I believe it is possible to profile machine twin scroll T4 flanged housings to take a GT3582R cartridge , search GT35T4 because I think I got a few examples to read about .

As per the EJ25 that's a different can of worms . The flatulence fours are a long way between the exhaust ports and not impossible but involved to do TS header manifolds for . In their favour they have 600+ cc cylinders and a large bore size , the the shortish rods don't really compliment their stroke though . I'd be a bit worried about gearboxes on the Roo's but that hasn't stopped people running big turbos on them .

Tiz a great pity that there were never LHD R32/33/34's because the Americans would have had better things to play with through the 90's .

Out of time again back later Cheers A .

Must read the FR stuff in those links when I get the chance , I should have guessed it'd have Geoff Raicer all over it !

[XRATED]

Dose 3076r come in a 0.63, 0.82 and 1.06 internal gate housings? I like the flexability of being able to use different housings to make different power, but I'd like to keep the packaging stock looking... eg stock manifold. Power goals are 240rwkw at low ish boost, the 280odd when I re-build the bottom end (RB25DET).

Cheers

Justin

[Roy]

Is that because your trying to sell one?

It was actually a joke. He considered buying mine but i dont think it was what he was after and i am now wanting to keep it.

There are fans of each brand. From those i know who have run the HKS 3040 and the 25G on very similar cars and same dyno the 25G makes more power then the 3040 and is tad more responsive, so is obviously laggier then 3037 but you get that if you are chasing those extra few top end kws.

The 3037 is the solid all rounder and the better choice!

[WYTSKY]

It was actually a joke. He considered buying mine but i dont think it was what he was after and i am now wanting to keep it.

There are fans of each brand. From those i know who have run the HKS 3040 and the 25G on very similar cars and same dyno the 25G makes more power then the 3040 and is tad more responsive, so is obviously laggier then 3037 but you get that if you are chasing those extra few top end kws.

The 3037 is the solid all rounder and the better choice!

yeh cheers roy, i did say some silly response to u, but it got lost in here pretty quick

if i had the money, know how and time, that turbo would be sitting in my lounge room instead of this one, but for my car at the moment, this appears to be the sensible choice... and im happy with it

hope it goes well for you mate.

[Dale FZ1]

ATPturbo.com have a .78 divided housing as an option.

T3 .78 IMO would be too small for a 2.5 litre especially with a GT35. IMO the .78 is just marginal with a 3076 on a SR.

Twin scroll ex housings seem to need more ex a/r so they don't fall over in the upper rpm range. Thankfully they have less lag induced from using larger twin scroll housings than compared to their open housings counterparts.

Given the application of a high comp 10:1 25DE bottom end, and the choice of a 3076 cartridge, I'd have swayed towards the split pulse if the budget would stretch.

The cost of a properly made split pulse manifold + external gate on top of the turbo would certainly make for an expensive fitup though

With regards the GT35 to 30DET match (a bit OT, I thought??), I've been for a run in a fairly serious Toyota IS300 running a 2JZ 3.4 Jun stroker kit with GT35. Not directly comparable to the 30DET, but extremely progressive, and it evidently took away the bottom end savagery + allowed about another 80hp to the max output. Balance that against the results Al achieved with his 30DET + 3076, and I think that whether to run a GT30 or GT35 on a 30DET would probably come down to application (road or track/strip), and how much money has been spent on the RB30 rotating assembly - ie is it configured to rev reliably?

On subject, the 0.63 + EW should make decent power + response as WYTSKY wanted. I'd be interested in the results, and also to see the ignition map once it's tuned.

[WYTSKY]

no worries Dale, i'll keep you guys updated... still got a fair bit of parts to scavenge for first though.

Adam

[GT-RZ]

i'm satying tuned in for a while

[discopotato03]

Every one's going to have their own ideas and that's fine , I don't mind airing mine as long as people don't take them as gospel . I try to look at things from the perspective of what I think an engine will like given its spec/state of tune .

NA engines are a different ball game because they are intended to work only with atmospheric pressure to charge their cylinders . They don't have a turbine and housing placed in their exhausts so at bit less restriction close to the engine itself .

They are also cam'd to suit the higher compression ratio so that they get a dynamic (effectively throttled CR) to suit their requirements . Also pistons don't cop the thermal lashing that turbo ones do so aren't made to cope with conditions they normally wouldn't see .

IMO (only) a higher static CR engine is going to make more off boost torque than a lower or turbo one because generally the cylinder pressures are higher . Na engines usually are not keen on having your typical OEM small turbos turbine/housing in the exhaust tract and it makes them restrictive and inclined to detonate early .

Na engines because of their higher cylinder pressures and temperatures (compared to a turbo engine off boost) have sharper exhaust pulse energy and would try a drive a turbo into boost a little sooner than a lower comp engine would .

My gut feeling is that since the higher comp engine is going to make a bit more torque down low and you wouldn't be making efforts try and spool the turbo at that stage . I'd be inclined to use larger turbine housings to give the engine a less restrictive more NA like exhaust tract to exhale into . The thing is that the larger the turbine housings AR is the less the requirement for high flowing waste gates becomes because more gas can pass through the larger passage and through the same turbine blades . Less to "waste" or bypass for controlling turbine speed and therefore boost pressure .

We have to remember that a waste gate , because they are usually signalled/referenced off inlet pressure) , cannot be regarded as an exhaust side pressure relief valve . The things aren't intended to even start to crack open until the intended boost pressure is approached and if the exhaust manifold pressure is too high for the engine to cope with before this the waste gate doesn't know or care .

DE + T engines can work OK but the user has to be that much more careful to keep an eye on exhaust gas temperatures and pressures because if they run riot they can and will kill your engine .

The manufactures use lower comp pistons in forced induced engines so that they can survived the artificially increased CR of a boosted engine , if the higher NA CR is boosted then the cylinder temperatures and pressures invariably go higher than the turbo versions do and lesser spec pistons are left to cope or fail in a tougher environment .

So IF you can keep the temps and pressures down to that which the engine can cope with and tune it properly then it has a reasonable chance of surviving .

I don't know this posters circumstances but even if on a budget I'd look seriously at a cheaply freshened up VL RB30 NA engine , mod the block to fix the front gallery issues and go away laughing with 8.3 or whatever CR . Bigger lower pressure/temp Masi Ferguson and NO issues spooling a GT3076R .

Just my thoughts , cheers A .

[discopotato03]

Every one's going to have their own ideas and that's fine , I don't mind airing mine as long as people don't take them as gospel . I try to look at things from the perspective of what I think an engine will like given its spec/state of tune .

NA engines are a different ball game because they are intended to work only with atmospheric pressure to charge their cylinders . They don't have a turbine and housing placed in their exhausts so at bit less restriction close to the engine itself .

They are also cam'd to suit the higher compression ratio so that they get a dynamic (effectively throttled CR) to suit their requirements . Also pistons don't cop the thermal lashing that turbo ones do so aren't made to cope with conditions they normally wouldn't see .

IMO (only) a higher static CR engine is going to make more off boost torque than a lower or turbo one because generally the cylinder pressures are higher . Na engines usually are not keen on having your typical OEM small turbos turbine/housing in the exhaust tract and it makes them restrictive and inclined to detonate early .

Na engines because of their higher cylinder pressures and temperatures (compared to a turbo engine off boost) have sharper exhaust pulse energy and would try a drive a turbo into boost a little sooner than a lower comp engine would .

My gut feeling is that since the higher comp engine is going to make a bit more torque down low and you wouldn't be making efforts try and spool the turbo at that stage . I'd be inclined to use larger turbine housings to give the engine a less restrictive more NA like exhaust tract to exhale into . The thing is that the larger the turbine housings AR is the less the requirement for high flowing waste gates becomes because more gas can pass through the larger passage and through the same turbine blades . Less to "waste" or bypass for controlling turbine speed and therefore boost pressure .

We have to remember that a waste gate , because they are usually signalled/referenced off inlet pressure) , cannot be regarded as an exhaust side pressure relief valve . The things aren't intended to even start to crack open until the intended boost pressure is approached and if the exhaust manifold pressure is too high for the engine to cope with before this the waste gate doesn't know or care .

DE + T engines can work OK but the user has to be that much more careful to keep an eye on exhaust gas temperatures and pressures because if they run riot they can and will kill your engine .

The manufactures use lower comp pistons in forced induced engines so that they can survived the artificially increased CR of a boosted engine , if the higher NA CR is boosted then the cylinder temperatures and pressures invariably go higher than the turbo versions do and lesser spec pistons are left to cope or fail in a tougher environment .

So IF you can keep the temps and pressures down to that which the engine can cope with and tune it properly then it has a reasonable chance of surviving .

I don't know this posters circumstances but even if on a budget I'd look seriously at a cheaply freshened up VL RB30 NA engine , mod the block to fix the front gallery issues and go away laughing with 8.3 or whatever CR . Bigger lower pressure/temp Masi Ferguson and NO issues spooling a GT3076R .

Just my thoughts , cheers A .

[GT-RZ]

Well apparently the gt35r with 1.06 TS housing is not available according to lewisengines? But maybe the GT30 with the 1.06 rear is, so i may be going down that road!

ah well. really this car is going to be built for drift and maybe some circuit/hill climb work so response is paramount. will probably never see a drag strip.

But if anyone knows of a place i can get the GT35 TS from let me know!

cheers.

[Lithium]

But if anyone knows of a place i can get the GT35 TS from let me know!

Look here - ignore turbine housing a/r and check the turbine housing style list, near the bottom is what you are looking for:

http://www.atpturbo.com/Merchant2/merchant...tegory_Code=GRT

[GT-RZ]

Look here - ignore turbine housing a/r and check the turbine housing style list, near the bottom is what you are looking for:

http://www.atpturbo.com/Merchant2/merchant...tegory_Code=GRT

aha thank you very much! 'Divided T4 flanged turbine inlet with 3" v band (1.06 only)' i shall show them that!

[Dale FZ1]

Engine-wise the biggest hurdle Adam has is the model – it’s a GTS4. Things I see as negatives with that spec engine are 1. conrods 2. unknown piston suitability at the targeted power output 3.lack of under piston cooling oil jets 4.cam spec.

Doing something with the bottom end is similar to any GTR going to RB30 from a fitup viewpoint. That would mean an adaptor kit, so not all bad. The extra grunt from +500cc would be very attractive, and CR is forced aspiration friendly.

A Stagea spec RB25 bottom end should be readily available (cheapish), with rods similar to RB26 (beefier), and oil squirters as stock. I view the squirters as a very important part of the high-comp equation, as they can keep temps out of the pistons – reducing knock tendencies and chance of pistons nipping up tight in the bores. And it would bolt in.

Optimising cam profile would take a bit of homework, and as per comments in Adam’s TD06 thread, obtaining/maintaining effective scavenging would have to be one of the critical aspects of having this high comp engine run and make the power target without detonation. Measurements and exact specs are not known to me, but if 25DE cams run slightly wider overlap than a DET, it for forced aspiration could be a good thing for torque production across the range (with a negative for fuel consumption). Drop in some DET cams (cheap) and it would be an interesting back to back comparison.

There is no argument that the 0.63 turbine housing will increasingly be a restriction as the engine revs harder / makes more power / has greater mass-flow throughput. In some respects the issue of whether it is detrimental to the match with a 25DE is trial and error. Going by Mafia’s experience, he hits 19psi @ 3200rpm. An engine will be most knock sensitive when making peak torque due to that being when the most work is done. With this 25DE+T I’d see the rpm range between 3200 – 5000 as where it’d be most knock sensitive.

Here’s where I have a slightly different view to Adrian in that across that critical range the wastegate is open, and venting excess gas flow to control turbine speed. At the same time, it is clearly dropping the turbine inlet pressure and tending to aid the all important scavenging. The rider to making all this work for me would have to be manifold design and wastegate size + placement. I wouldn’t be confident that there is sufficient room in a low mounted position to weld a vent tube direct onto the turbine housing and still achieve a free flowing result. For that reason I’d go straight towards a decent collector style manifold with provision for EW venting before the turbine.

I think the EW 0.63 GT30 can work well on the 25DE+T, but getting the detail right is going to be super important if it’s going to make the power and live. The ignition mapping is going to tell a similar story as measuring pressures in the exhaust manifold ie. just how well it works in practice.

[discopotato03]

Just to quantify my opinions only on waste gates and exhaust manifold pressure - good to see that opinions can differ without daggers drawn !

What a waste gate sets out to do is make a controlled "leak" so that some of the exhaust gasses bypass the turbine to slow its rate of acceleration as the engine speed rises .

To my way of thinking if the waste gate opened enough to make a substantial drop in manifold pressure and therefore gas speed the turbine would slow and take boost pressure with it because the turbine and compressor wheels are fixed on the same shaft .

That's why I said that waste gates are almost always signalled by inlet manifold pressure and have total disregard for exhaust manifold pressure . Its very common to see OEM engines with two and a half plus times inlet manifold pressure in the exhaust manifold under boost .

The roads to a really stonking and reliable turbo engine are a 1 to 1 ratio of pressure in both manifolds , it's this pressure balance across the head (actually across the inlet and exhaust ports) that allows an engine to scavenge effectively and not melt down .

This is why (IMO anyway) a wastegate shouldn't be viewed as a pressure relief valve , if you wanted the waste gate to regulate off exhaust manifold pressure you'd have to get the signal pressure from the exhaust manifold .

If your going to use a waste gate to regulate air pressure other ways have to be found to make sure exhaust manifold pressure and temperature don't get out of hand .

The Garrett people OS told me that it's always preferable to use a larger AR turbine housing if exhaust pressure is getting a bit high , you can go to a larger turbine but the disadvantage to a degree is accelerating its greater mass (larger diameter) and if it has more compressor than you can use in a bulkier heavier compressor housing it gets a bit self defeating in a few different ways .

Where IMO the larger turbine housing on a GT3076R pays off is that you get a decrease in exhaust manifold pressure and an increased range where ALL the exhaust gas is going through the turbine - ie waste gates shut longer .

So with the decrease in exhaust pressure the engines wants to scavenge better and have lower pumping losses , they can usually take more ignition advance if needed because with lower exhaust pressure the detonation threshold can drop away too .

The turbine size and mass hasn't changed but you can get a fair bit greater flow through it .

When the whole turbo size increases the bulk and weight goes up with it and that doesn't fit in with power to weight and ease of maintenance aspects .

Anyway out of time , got to run the Indian out to Parkes this afternoon so chow for now .

A .

Edited August 29, 2009 by discopotato03

[wolverine]

Disco, I'm not sure if I am a bit thick but wouldn't the wastegate opening lower the exhaust manifold pressure in any application be internal/external once it cracks open. It should vary the level of pressure from which the restriction is eased whereas a larger AR gives a higher threshold before things get out of hand.

Does the engine differentiate the degree of scavenging when the exh manifold pressure is lowered by a larger turbine housing or when the wastegate opens?

I am certainly not disagreeing with the logic of a larger turbine to give you a lower base exhaust manifold pressure/restriction and pushing more timing to compensate down low as this is similar to the path that my R33 has gone down (albeit with a compressor that is a whisker bigger than ideal for me).

[GT-RZ]

what are your guys thoughs on the gt3082 as a medium between the gt3076 and the gt35? if i go either it will be 1.06 but obviously the option for twin scroll is only available for the gt35 as it uses the larger T4 footprint!

Really anywhere between 350-400kw is perfect but nearer the >350 mark is more my goal. Engine is going to be running 8.7cr forged 26/30. will choose cams (possibly regrind) when i know what turbo i want response is paramount, rather that than the higher power figure.

thoughts appreciated!!

[Lithium]

Really anywhere between 350-400kw is perfect but nearer the >350 mark is more my goal. Engine is going to be running 8.7cr forged 26/30. will choose cams (possibly regrind) when i know what turbo i want response is paramount, rather that than the higher power figure.

If you want >350rwkw then don't mess with a GT30 hot side in my personal opinion. I know there are varying theories on the matter, but one of my good friends had a .82a/r GT3082R on his EVO and ended up running to the limit of its hot side and replaced with with a .82a/r GT3582R. He swears black and blue that in the real world the GT3582R was the better package and basically considered the GT3082R a bit of an unnecessary distraction. His car since going to the GT35R is more pleasant to drive, tune, and goes faster all around.... going by anyone I know who have used them and then moved on, the 3082R seems like an answer to a question which shouldn't have been asked.

Honestly, as soon as you say you are targetting 350kw I feel the GT30 series should be ruled out - especially when you have the T4 TS GT35R as an option. If my crystal ball is at all accurate, your spool and response will probably rival the GT3082R lads (not that there are many out there) but your midrange torque and peak power will leave them hiding in the shadows.

Edited August 30, 2009 by Lithium

[SLAPS]

In my experience on pump fuel with the stock exh. manifold regardless of the turbo (gt35 or gt30) you'll be pushed to make much more than a little over 300rwkw on a DD Dyno even then it can be a stretch.

I believe a 1.06 GT30 would only reduce average power.

Mine on std cams and a .82 GT30 was making peak power at 6k and would then fall over fairly quickish but not all that noticable seat of the pants. A set of cams and it held power flat line from 6k to 7k and picked up 26rwkw on the same boost. The cams allowed the car to run a fair bit more timing. All round it was much happier and didn't feel so on edge with the ign. timing requirements.

Two mates with a near identical motor/setup but with a GT35r .82 identical setup made pretty much identical power on the stock manifold to my GT30 .82. The better flowing GT35 .82 hot side on the stock exh manifold did nothing for power. I see this experience as being comparable to the 1.06 GT30 line of thought.

I should also mention on the dyno the GT35 .82 didn't actually lag far behind the GT30 in terms of out right spool. Drive the cars back to back the difference is extremely noticable in first and second. The GT35 on the RB30 in comparison to the GT30 made it feel like a pig to drive as you had to give it too many rev's in first/second to really get the turbo spooling well. The GT30 had quick responsive spool that made getting the power down easier as it wasn't a lag lag snap power delivery like the GT35 in comparison. I think of it like slamming the brakes on vs feeding the brakes on progressively. Much harder to get those wheels locking.

However, mine is no longer driven on the street (not defected but it was a bit silly for the street, it was just a matter of time before it caused me to loose my license as I found WOT = a slight tail wag in third (depending on road surface) a little addictive. I've now dropped the std exhaust manifold in favour of a HKS cast item and will be bolting up a GT35 .82 aiming for 350rwkw+ on pump. Fingers crossed.

A little O/T but I've also removed the blocked rear oil restrictor and 1.5mm front as the back left side of the head began showing signs of excessive heat. It looks to me the hydraulic heads really need 2 smaller oil restrictors as there was a little noise from that back end end of the head on cold start up directly after fitting the 1.5mm front and blocked rear.

Lith, as for the T4 TS GT35R. Its only a drill tap, slight port of the HKS manifold and turbine housing change.

Fingers crossed the HKS manifold supports the power level and doesn't cap out like the stocker does.

If I were to do it again.. GT30r .82 on stock manifold for >310rwkw (pump fuel). Anything bigger on the stock manifold is a waste.

Edited August 30, 2009 by SLAPS