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1994 Toyota Supra Turbo 6spd
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for those that have or have any actual information about the HKS T51r turbos. i was curious as to when the turbo started making boost and when it made full boost by?
hopefully with a 6spd car in 4th gear.

i am asking of the T51r KAI and SPL

i know the KAI is a 71mm turbo and the SPL a 76mm turbo but both have a big 1.0 a/r exhaust housing

thanks
 

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The T51R SPL is actually a better turbo for the Supra... Both the KAI and SPL shares the same turbine specs, but the Supra seems to like a bit heavier on the compressor side.

Compared to similar sized turbos, the HKS T51R's has a huge turbine housing so it will always be laggier to say a PTE71 or 76mm turbos... All the common 71mm or 76mm turbos come with smaller exhaust side to encourage earlier boost, but then response and breathability up at higher RPM's are compromised. Exhaust pressures also skyrocket if you decide to fully use up a 76mm but with a small 0.69 or 0.82 A/R housing.

I personally like the T51R turbos because they seem to breathe so well and allow lots of power on pump gas. It seems like whatever car I put the T51R into, the engine allows way more timing, more boost and more power on the usual 94oct pump gas at Sunoco. The lag is there at low RPM's, but the fact that this turbo is really responsive, it never falls off between shifts. Of course, to whoever that is shopping for a 76mm turbo, cams, valvetrain and a higher redline is mandatory to allow a decent powerband. But due to the HKS T51R turbo and some tweaking with the cam gears w/ HKS 264's, I managed to make power all the way up to 8000RPM.

I don't have dynos of clean comparison between the two turbos because I just recently discovered I had a leaking BOV... All my graphs had a leaky BOV and the spool time is way off... But here's a few graphs:

HKS T51R SPL on my Supra, 50% 115oct and 50% 94 oct, + water/meth



T51R KAI on my Camry, 3.0L V6, 94 oct and water/meth:
 

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The T51R SPL is actually a better turbo for the Supra... Both the KAI and SPL shares the same turbine specs, but the Supra seems to like a bit heavier on the compressor side.

Compared to similar sized turbos, the HKS T51R's has a huge turbine housing so it will always be laggier to say a PTE71 or 76mm turbos... All the common 71mm or 76mm turbos come with smaller exhaust side to encourage earlier boost, but then response and breathability up at higher RPM's are compromised. Exhaust pressures also skyrocket if you decide to fully use up a 76mm but with a small 0.69 or 0.82 A/R housing.

I personally like the T51R turbos because they seem to breathe so well and allow lots of power on pump gas. It seems like whatever car I put the T51R into, the engine allows way more timing, more boost and more power on the usual 94oct pump gas at Sunoco. The lag is there at low RPM's, but the fact that this turbo is really responsive, it never falls off between shifts. Of course, to whoever that is shopping for a 76mm turbo, cams, valvetrain and a higher redline is mandatory to allow a decent powerband. But due to the HKS T51R turbo and some tweaking with the cam gears w/ HKS 264's, I managed to make power all the way up to 8000RPM.
The GT42-76 is available in .98 (PTE Housing), 1.01, 1.12 (PTE), 1.15, 1.28, 1.44, 1.01 T6, 1.15 T6

The T88H38GK (76mm) is available only in 18cm^2 and 22cm^2 housings

Turbonetics stuff can be purchased with a huge range of housings.

In reality, the only popular 76's on the market where you can only get sub-1.00 housings are the Precision stuff where you can only get a .81 or .96 undivided tangental T4.

The T51R turbine wheel is (as I understand it) simply an older version of an 82mm wheel (like the GT42) with a different Trim. Jose from Forced Inductions would be a better source of information on the T51R than myself though. I believe he's the one I was speaking with about the turbine wheel - I don't remember at this point though.
 

· King of Snark
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how'd you get 900 out of the t-51? I am running the t51-s and only put down 578 on pump.
 

· King of Snark
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that was the camry. I wonder what set up he was running on the supra.
 

· King of Snark
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sorry missed it.. i won't lie i didn't see it at first. my bad
 

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The GT42-76 is available in .98 (PTE Housing), 1.01, 1.12 (PTE), 1.15, 1.28, 1.44, 1.01 T6, 1.15 T6

The T88H38GK (76mm) is available only in 18cm^2 and 22cm^2 housings

Turbonetics stuff can be purchased with a huge range of housings.

In reality, the only popular 76's on the market where you can only get sub-1.00 housings are the Precision stuff where you can only get a .81 or .96 undivided tangental T4.

The T51R turbine wheel is (as I understand it) simply an older version of an 82mm wheel (like the GT42) with a different Trim. Jose from Forced Inductions would be a better source of information on the T51R than myself though. I believe he's the one I was speaking with about the turbine wheel - I don't remember at this point though.
The specs of the T51R turbine can actually be found on HKS' website... Both the turbine exducer/inducer specs are there, so the trim can be calculated if someone wants to compare straight up with the GT42 turbos. From a lot of the kits being sold, I rarely see 1.00+ a/r housings unless folks step up a GT42R or other less common turbos (BW, GTK, etc)..

From what I am experiencing with the HKS turbos, it could simply be flow improvements due to the V-band exhaust housings. The V-band housings really improve the transient response, both in or out of boost.. I had smaller turbo setups with drastic improvements just from jumping to a V-band turbine housing within the same A/R. I never had a GT42R equivalent with a V-band option, so I don't have much data in regards to that. But if I were to purchase a GT42R with Tial V-band, all the flanges, dressed, a manifold modified to accept a Tial V-band, etc.. It was far easier and very similar costs for me to just get an HKS V-banded manifold with an HKS T51R.
 

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No i know the specs are on the website, it's a 76 trim where the GT42 is an 84 trim. What I was more speaking to is that I believe it's an older version, and not necessarily a cut down version of the current generation GT42 wheel.

My comment about A/R was more because of how your comment was worded.

All the common 71mm or 76mm turbos come with smaller exhaust side to encourage earlier boost, but then response and breathability up at higher RPM's are compromised. Exhaust pressures also skyrocket if you decide to fully use up a 76mm but with a small 0.69 or 0.82 A/R housing.
You said "All" when in fact, there really is only one common turbo where you're stuck with a sub 1.00 A/R T/Hsg.
 

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My comment about A/R was more because of how your comment was worded.

You said "All" when in fact, there really is only one common turbo where you're stuck with a sub 1.00 A/R T/Hsg.
Are we really getting that bored these days to discuss what you believe is common out there? lol All the other turbos you've listed above isn't really common in my books. How many Turbonetics, GReddy T88H or GT42's are out there in comparison to the ever so popular PTE 76's, 78 GTS etc.. you know, these PTE turbos are direct bolt on for existing common BL turbo kits, SP, etc.. and that's why we see soo many of them. I am not going to convince you as to what you believe is common.
 

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Listen, YOU brought up the word common. I simply corrected you in that there are very few 76mm turbochargers out there with less than a 1.00 A/R. I didn't even touch on the fact that I can't think of one 76mm that uses a .69 or .82.
 

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seeing as you ran over 900whp on 94 and meth/water, can this turbo hit the 1000whp mark with the proper tuning and engine build? i have also searched and found alot of people using the kai in their supra, and i love the way it sounds. does the spl sound the same? i have seen your video when you had a kai in the dawg, is the turbo spool sound similar to the kai? to be honest i am looking into getting my dawg pretty soon, got pulled behind since im getting married and closing on my house this coming month. once thats done then i can get the dawg, but i am really looking to get the car drive it for a while with a nice turbo setup on low boost, save some more cash and go with a built motor. i am really looking to have a 1000whp supra. nothing less. anything above that will just be sweet. so far i was stuck on going with a gt47-80, but now, i want to know if the t51r spl can make what i want.
 

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I have a 76gts with a .82 on it :)
Great to know :) My buddy also has one on his Skyline as well.


seeing as you ran over 900whp on 94 and meth/water, can this turbo hit the 1000whp mark with the proper tuning and engine build? i have also searched and found alot of people using the kai in their supra, and i love the way it sounds. does the spl sound the same? i have seen your video when you had a kai in the dawg, is the turbo spool sound similar to the kai? to be honest i am looking into getting my dawg pretty soon, got pulled behind since im getting married and closing on my house this coming month. once thats done then i can get the dawg, but i am really looking to get the car drive it for a while with a nice turbo setup on low boost, save some more cash and go with a built motor. i am really looking to have a 1000whp supra. nothing less. anything above that will just be sweet. so far i was stuck on going with a gt47-80, but now, i want to know if the t51r spl can make what i want.
That's my goal for this year, and I really want to see if I can hit the 1K RWHP mark with the SPL. The trick is to let the turbo run at its peak efficiency point, both on the compressor and turbine side. With my current stock head and 264 cams, I won't be able to get there though.. My next step is a built head with GSC S2 cams (built bottom as well to sustain more revs) but I am staying with a 3.0L due to being able to hold torque nicely up to 8000-8500RPM. Theoretically, the amount of flow that the engine will ingest should put me to 1000WHP just around 30-32 PSI, and that will be the sweet spot at the upper end of the flow map for the T51R SPL. The 3.0L bottom-end will cut the torque down a bit so the turbine side will be at its peak efficiency range as well (and not overpowering the turbine and begin to have increased exhaust pressures). A 3.4L stroker will not reach 1000 WHP on the HKS T51R.

The T51R SPL does sound the same as the KAI... You must get the ball bearing cartridge though if you want the infamous louda$$ turbo accel/decel "winding down" sound that lasts for like 15 secs :)
 

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Great to know :) My buddy also has one on his Skyline as well.




That's my goal for this year, and I really want to see if I can hit the 1K RWHP mark with the SPL. The trick is to let the turbo run at its peak efficiency point, both on the compressor and turbine side. With my current stock head and 264 cams, I won't be able to get there though.. My next step is a built head with GSC S2 cams (built bottom as well to sustain more revs) but I am staying with a 3.0L due to being able to hold torque nicely up to 8000-8500RPM. Theoretically, the amount of flow that the engine will ingest should put me to 1000WHP just around 30-32 PSI, and that will be the sweet spot at the upper end of the flow map for the T51R SPL. The 3.0L bottom-end will cut the torque down a bit so the turbine side will be at its peak efficiency range as well (and not overpowering the turbine and begin to have increased exhaust pressures). A 3.4L stroker will not reach 1000 WHP on the HKS T51R.

The T51R SPL does sound the same as the KAI... You must get the ball bearing cartridge though if you want the infamous louda$$ turbo accel/decel "winding down" sound that lasts for like 15 secs :)


thanks tony. i have been seeing more and more on your camry and supra. i saw the spl supra video. i like how your neighbors were all looking as you pulled up to your driveway! :roflmao: my goal is to have a 650-730whp supra until i can go with a built engine, meaning internals, built head with a good set of cams. i am waiting to stay with the 3.0 and not stroke it, and wanting to go into high rpms, somewhere in the 8k-8500rpms is perfect. will take a long time for me to get there. by the end of this yr i am hoping to have my toy. 5 weeks and we close on the house! after that is save and look to find the dawg! thanks on the info bro. now knowing that i will be able to hit 1k with a built engine and high revs is awesome. and thanks on the tip for the winding down. thats exactly what i want :)
 
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