Max horse power stock internals?

[Sleepergm]

Hi all, 

Been working on my hks ss turbo setup and making around 540hp without doing a 2.8L stroker upgrade. I feel this is a safe level with the weak link rod screw bolts I heard. What is everyone else putting out safely? I’m running 1.4 bar right now max on 98. I think with the tomei stroker kit I will be able to max the turbos out at around 650hp crank safely.  My friends putting down 525whp with the garret 7s and stroker kit already. 
 

What’s everyone’s thoughts? 
 

I have added my first dyno runs yesterday that I recorded. Curve is super smooth with horse power delivery with twins. Thanks 

[joshuaho96]

3 hours ago, Sleepergm said:

Hi all, 

Been working on my hks ss turbo setup and making around 540hp without doing a 2.8L stroker upgrade. I feel this is a safe level with the weak link rod screw bolts I heard. What is everyone else putting out safely? I’m running 1.4 bar right now max on 98. I think with the tomei stroker kit I will be able to max the turbos out at around 650hp crank safely.  My friends putting down 525whp with the garret 7s and stroker kit already. 
 

What’s everyone’s thoughts? 
 

I have added my first dyno runs yesterday that I recorded. Curve is super smooth with horse power delivery with twins. Thanks 

The GTIII-SS turbos are not made for 650 hp crank. They just aren't going to do it. The turbine housing is smaller than the Garrett -7s. The turbo in general is smaller than a GT2860R-7, if it makes the same power as -7s you should be happy. Honestly I would be really happy with your results as far as power delivery goes. Hitting peak torque by 3500 rpm if that's actually happening in 4th gear in the real world is not normal for an RB26 at all. I have heard of people doing 2.8 strokers with GTIII-SS engines but I don't think I've ever seen a dyno sheet of it. I would be worried that the torque falls off faster than RPMs can rise so instead of getting a wider power peak you just shift the whole curve down 500-1000 RPM and end up with an engine that's no fun to rev out.

[Sleepergm]

15 hours ago, joshuaho96 said:

The GTIII-SS turbos are not made for 650 hp crank. They just aren't going to do it. The turbine housing is smaller than the Garrett -7s. The turbo in general is smaller than a GT2860R-7, if it makes the same power as -7s you should be happy. Honestly I would be really happy with your results as far as power delivery goes. Hitting peak torque by 3500 rpm if that's actually happening in 4th gear in the real world is not normal for an RB26 at all. I have heard of people doing 2.8 strokers with GTIII-SS engines but I don't think I've ever seen a dyno sheet of it. I would be worried that the torque falls off faster than RPMs can rise so instead of getting a wider power peak you just shift the whole curve down 500-1000 RPM and end up with an engine that's no fun to rev out.

Thanks for the info. With the 2.8L stroker kit what would be the best single turbo setup for around 700-750 drivable horsepower? As I think after that it’s going to be very aggressive power delivery. 

[Butters]

It's a lottery, no one is going to be able to predict how much HP YOUR engine is going to handle as history has a huge part to play. 

 

As examples though.

I have one rb26 on 630rwhp, running 16 years now at that level, track use, only a couple of times a year. 

Another 790rwhp, about 2 years now, driven every weekend. 

 

If i was to give you a "safe" number I would say 450rwhp on 98 and 550-600 on e85. 

Seen plenty of motors pop with less though too  

 

 

[GTSBoy]

G30-770.

So long as you're talking engine horsepower, and not some bullshit wheel/axle/mystery horsepower.

[joshuaho96]

3 hours ago, Sleepergm said:

Thanks for the info. With the 2.8L stroker kit what would be the best single turbo setup for around 700-750 drivable horsepower? As I think after that it’s going to be very aggressive power delivery. 

I think you want an RB34 build at that point to go with a G30-770. Also if your dyno is reporting whp and not crank horsepower you should know your tuner is probably massaging the correction factors to make customers feel better. GTIII-SS and -7s are good for high 300 whp on pump gas, maybe just over 400 whp depending on the setup. E85 will push it into the mid 400 whp or so.

[Sleepergm]

57 minutes ago, joshuaho96 said:

I think you want an RB34 build at that point to go with a G30-770. Also if your dyno is reporting whp and not crank horsepower you should know your tuner is probably massaging the correction factors to make customers feel better. GTIII-SS and -7s are good for high 300 whp on pump gas, maybe just over 400 whp depending on the setup. E85 will push it into the mid 400 whp or so.

I think the figures are pretty accurate as all my other cars are around the right hp readings as have done on multiple dynoes. However they are rwd cars so might mean the difference. 
 

I am running every possible hks part also and a str exhaust … all new ecu. The mod list is endless. 😂 I’m ready for stroker and big turbo if I go that route. 

[Sleepergm]

My whp was 418whp and 518hp crank on 98 octane fuel. So decent numbers. 

[joshuaho96]

1 hour ago, Sleepergm said:

My whp was 418whp and 518hp crank on 98 octane fuel. So decent numbers. 

IMO I would stop there but it's up to you. At the power numbers you're asking about the stock 05U block will start showing issues. Even an N1 block might not be enough. PRP is trying to do blocks and heads that will be ready for big power right out of the gate but it remains to be seen whether any of that is any good. It might be great. It might be awful. It's hard to say until enough people have gotten their hands on one and run it for extended periods.

[Sleepergm]

17 minutes ago, joshuaho96 said:

IMO I would stop there but it's up to you. At the power numbers you're asking about the stock 05U block will start showing issues. Even an N1 block might not be enough. PRP is trying to do blocks and heads that will be ready for big power right out of the gate but it remains to be seen whether any of that is any good. It might be great. It might be awful. It's hard to say until enough people have gotten their hands on one and run it for extended periods.

This is what I was looking at next: 

https://www.z1motorsports.com/engines/tomei/tomei-rb26-28l-short-block-assemblies-p-45479.html

as we can’t bore the cylinders out in hk so better just buy the whole lot in one and install then retune. Everyone saying the weak link are the bolts holding the rods together. I already did valve springs, arp head bolts, hks racing coils, nismo fuel pumps and pressure regulators, injectors etc for the top of the engine. 

[joshuaho96]

16 minutes ago, Sleepergm said:

This is what I was looking at next: 

https://www.z1motorsports.com/engines/tomei/tomei-rb26-28l-short-block-assemblies-p-45479.html

as we can’t bore the cylinders out in hk so better just buy the whole lot in one and install then retune. Everyone saying the weak link are the bolts holding the rods together. I already did valve springs, arp head bolts, hks racing coils, nismo fuel pumps and pressure regulators, injectors etc for the top of the engine. 

https://www.platinumracingproducts.com/en-us/products/nissan-rb26-cast-blocks

This is the solution I was thinking of. I would stay away from Tomei USA, their quality is a question mark to me. If you want an engine machined in the US contact Club DSPORT: https://clubdsport.com/

Tomei JP is probably fine but I recall they stopped doing pre-assembled short or long blocks. In general it's pretty tough to get any kind of RB26 block at the moment with Nissan so severely backordered.

[Sleepergm]

6 minutes ago, joshuaho96 said:

https://www.platinumracingproducts.com/en-us/products/nissan-rb26-cast-blocks

This is the solution I was thinking of. I would stay away from Tomei USA, their quality is a question mark to me. If you want an engine machined in the US contact Club DSPORT: https://clubdsport.com/

Tomei JP is probably fine but I recall they stopped doing pre-assembled short or long blocks. In general it's pretty tough to get any kind of RB26 block at the moment with Nissan so severely backordered.

Yeah I heard the same. Might be hard to order one. But then I guess can go to hks or go to a more expensive n1 block with tomei. Guess will jump the hurdle once I get there next upgrade around. I can’t get work done in the states as the lead time will take for ever on top of shipping to Hong Kong. 

[Sleepergm]

And yes would be going to tomei Japan for sure as it’s closer to me …