2JZ-VVTi - T51r KAI

[denjil]

Hi all,

I am thinking of swapping my stock twin turbos to an HKS t51r kai. My Supra is a 1998 RZ VVTi manual model, engine is stock.

I would like a t51r mostly for the sound, i know this is an old turbo model but no other turbo sounds as good in my opinion. 

Could anyone from experience let me know what power I could expect from a stock vvti gte engine with a T51 and at what rpm the turbo would be on on boost? 

Thanks in advance,

Daniel

[Mike2JZ]

At full whack you will see somewhere between 700-800bhp. Advisable to stick some cams in engine and stock cams dont breath well over 6k and the turbo will want to make peak power after 6k. 

With VVTi, on full boost around 4500-4800rpm

[denjil]

8 hours ago, Mike2JZ said:

At full whack you will see somewhere between 700-800bhp. Advisable to stick some cams in engine and stock cams dont breath well over 6k and the turbo will want to make peak power after 6k. 

With VVTi, on full boost around 4500-4800rpm

Thanks for the info Mike. This is the turbo I am interested in, Can you confirm if this is the older KAI version non BB? 

[Mike2JZ]

@Supraleeturbohas the same turbo, although slightly newer version I think, but still KAI non DBB. 

At 1.8bar on a non vvti engine with 272 cams he did the following power at the wheels. Basically on full chat at 5k, but getting good momentum from 4.5k. 

With VVTi I'd expect you would move peak boost about 500-700rpm earlier. 

Supraleeturbo is going balls deep on a 3.4 stroker and vvti, so will have some data on the future on the worlds most responsive t51

[mattdavies]

21 minutes ago, Mike2JZ said:

@Supraleeturbohas the same turbo, although slightly newer version I think, but still KAI non DBB. 

At 1.8bar on a non vvti engine with 272 cams he did the following power at the wheels. Basically on full chat at 5k, but getting good momentum from 4.5k. 

 

 

 Is this turbo running out of steam towards the top end of the graph ? 

A friend of mine has a T51r on a built 3.0 with 269 cams, i dont have a graph but at 1.4 bar it was making about 640hp at the hubs at Abbey Motorsport.

He has bought the turbo not for response just for the noise and the spec list porn 

[Noz]

Ocdworks sell a modified compressor housing for most turbos.

I have one of their own turbos. Which sounds amazing.

I've ordered a 6870 with the T51r mod on it. Admittedly been waiting ages due to covid but always keep in mind you can mod the housing to sound just as good.

My current 62mm with T51r sounds so nuts I wanted another.

[Supraleeturbo]

1 hour ago, Mike2JZ said:

@Supraleeturbohas the same turbo, although slightly newer version I think, but still KAI non DBB. 

At 1.8bar on a non vvti engine with 272 cams he did the following power at the wheels. Basically on full chat at 5k, but getting good momentum from 4.5k. 

With VVTi I'd expect you would move peak boost about 500-700rpm earlier. 

Supraleeturbo is going balls deep on a 3.4 stroker and vvti, so will have some data on the future on the worlds most responsive t51

Hey mate I’m only running 264 cams 

[Mike2JZ]

6 hours ago, mattdavies said:

 Is this turbo running out of steam towards the top end of the graph ? 

A friend of mine has a T51r on a built 3.0 with 269 cams, i dont have a graph but at 1.4 bar it was making about 640hp at the hubs at Abbey Motorsport.

He has bought the turbo not for response just for the noise and the spec list porn 

I think after 2 bar boost its starts dropping boost near redline if I remember correctly. This is the T51 KAI which is smaller than T51R, T51R is a 1000hp+ turbo, so will make more power but less response compared to KAI  Ignore that, forgot the bigger ones called SPL not R. 

Sounds about right for 1.4 bar. Just checked lee's graph at 1.4 he was doing 620whp

Edited March 9, 2021 by Mike2JZ (see edit history)