25g comp wheel + clipped tdo5 in BEP bolt on?

[keith2g]

Wondering if anyone out there has experimented with this setup and if so, what type of results were achieved. Im currently running an MHI 20g that I purchased from Forced Performance in a BEP tdo5 bolt on and have been pretty pleased with the results.

The car recently went 11.7 @ 125mph with a 1.9 60ft on pump and meth (full weight). I plan to push this turbo to its limits and I'm looking at different alternatives to how I can do so. The turbo is in need of a rebuild so im currently pulling it but while I have it off of the car I plan to swap on a bigger compressor wheel and housing. The wheel is a 25g (60.2mm inducer 78mm exducer) and the compressor housing is an anti-surge 3" inlet. Im also sending the turbine wheel to gpopshop to have it clipped 15* (I know how some of you feel about clipping a wheel so please hold the negatives). The end result will be a clipped tdo5 anti-surge 25g in a BEP bolt on. Kinda sounds like a mutt but just curious as to how others might predict the performance of this setup. Any input will be greatly appreciated.

 

[agentorange313]

I would also like to hear more about this.

I am running a 20g TD05 in a BEP housing, I haven't maxed it out yet, but I want to know the options after I do. I know there are plenty of turbos that outflow a td05 20g, but I rather stay with a MHI build.

I was talking to jus a while back about a twinscroll 20g, using the evo x turbine housing. The 10cm twinscroll housing eliminates the need to have the turbine wheel clipped, and it will spool like a 16g. This is a project I am working on since I need a custom manifold and exhaust system.

I dont know how this will mate with a 25g compressor wheel though.

I have never seen a 25g wheel before in person, would it fit on a td05 CHRA? I know that this wheel will most likely be mated with a td06 turbine wheel in a bolt on td05 housing. Plus since its the BEP, it will definitely help out the td06 wheel breath, I believe BEP is a 8cm housing. That is if you want to have it machined to fit a wheel, BEP housing are rare now.

 

[JusMX141]

You're going to melt thrust plates. That is far too large of a compressor on that turbine wheel.

Biggest we ever ran on the 5H was the old 46trim T04E wheel, even then it didnt really run any better than a 20g 5H did.

Most would say there is a improvement even with the 20g wheel in running a turbine larger than a 5H, thats just a lot of inlet area and not a lot of outlet area. the 20g 6 or 20g 6H works well. And the more modern 6H4 with 11 blades works even better.

anything you run with a 5H is gonna have to work well at really high shaft speed, so think small diameter high flow high speed compressor when you look to a 5H turbine for power.

 

[Jon91TSi]

You're going to melt thrust plates. That is far too large of a compressor on that turbine wheel.

I was gonna say... I thought my 3076r wheel on my TD06H4 was a big 20g combo.. It sounds like this combo is really mis-matched. But hey, if it works

 

[keith2g]

JusMX141- Can you elaborate? Even with the turbine wheel clipped you feel that this combo wouldn't survive? Given your rep, I have no problem listening to your suggestions or recommendations. What other routes could I go as far as upgrading to a bigger comp wheel and comp housing? I appreciate any input.

 

[JusMX141]

Clipping is a good way to squeak an extra 1-2 lb/min of turbine flow on a relatively-balanced setup which may have a little more compressor than the turbine can handle in stock form. Clipping will NOT allow you to throw a 60 lb/min compressor on a turbine that normally maxes at 44 lb/min and expect miracles to happen. At best, I believe you're building what will end up being a really laggy 20G.

In regards to the thrust wear- shaft speeds will be higher than that compressor was designed for; the 25G compressor is already much larger and heavier than a 20G, and 20G's already have issues with the factory thrust system at boost levels where the compressor makes airflow. I've had guys run their 20G forever at 18-22psi, but as soon as their turn the wick up to 25-28psi they develop serious in/out play in as little as 500 miles.

The thrust loads you'll experience are more than the thrust parts were designed for, and more than the CHRA itself was designed to handle in terms of oil distribution to the thrust system.

 

[keith2g]

Im glad you chimed in on this. Ive currently been running the 20g at close to 30psi for about 5-6,000 miles and already I have to pull it because of a thrust failure. Pretty much if Im already having issues with the 20g wheel, your saying im almost guaranteed problems with an even bigger compressor wheel mated to this turbine. I appreciate the guidance.

 

[donniekak]

I've been running the 20g i bought from fp at 30+ psi for about 10,000 miles. Which in my car is an eternity considering my driving style. I only run vr1 synthetic 20w-50.

 

[JusMX141]

There are things that can be done to help with thrust issues...but they're sort-of a band-aid. There are steel thrust plates with two oiling holes and wider thrust collars available; using an oil with a high ZDDP level for better shear protection is also highly recommended.

Something else I failed to point out above with the 25G compressor on an 05H turbine....be ready for compressor surge out the asshole. You probably won't be able to make above 18-20psi without running into a wall of surge right at the onset of boost when the engine RPMs are low and the turbo RPMs are high due to high load and the small turbine wheel.

 

[crash89]

Clipping is a good way to squeak an extra 1-2 lb/min of turbine flow on a relatively-balanced setup which may have a little more compressor than the turbine can handle in stock form. Clipping will NOT allow you to throw a 60 lb/min compressor on a turbine that normally maxes at 44 lb/min and expect miracles to happen. At best, I believe you're building what will end up being a really laggy 20G.

In regards to the thrust wear- shaft speeds will be higher than that compressor was designed for; the 25G compressor is already much larger and heavier than a 20G, and 20G's already have issues with the factory thrust system at boost levels where the compressor makes airflow. I've had guys run their 20G forever at 18-22psi, but as soon as their turn the wick up to 25-28psi they develop serious in/out play in as little as 500 miles.

The thrust loads you'll experience are more than the thrust parts were designed for, and more than the CHRA itself was designed to handle in terms of oil distribution to the thrust system.

Well thats not something I wanted to hear.. I planned to try and run 27-29 psi on my 20g next season on the new build.. I hope I dont have this luck..

 

[keith2g]

I've been running the 20g i bought from fp at 30+ psi for about 10,000 miles. Which in my car is an eternity considering my driving style. I only run vr1 synthetic 20w-50.

Must be nice! Can you describe you oiling system a little? Oil feed, OEM return?, oil cooler, still the original brass thrust? Thanks.

There are things that can be done to help with thrust issues...but they're sort-of a band-aid. There are steel thrust plates with two oiling holes and wider thrust collars available; using an oil with a high ZDDP level for better shear protection is also highly recommended.

I hate to get off topic, especially when communicating with a mod but what type of oil do you use personally. Ive been doing a ton of research and like everything else, everybody's too opinionated for me to make a decision the has concrete data backing it up. I also read up on Brad Penn and have yet to hear anything bad. Thoughts?

 

[brian9397gsx]

I know I run rotella 15/40 fed from the head with a 2g, oil return line on my tdo5 20g and have had no problems with my thrust bearing.

 

[tron2119]

Justin- Would the 25g compressor wheel be better suited with the TD06h turbine wheel?I know what machine work would need to be done but how practical would this be? Would he be better off with upgrading to just a larger turbo in general?

 

[JusMX141]

It would be better-matched to the TD06H for sure, although you may want to clip the 06H turbine just for insurance that you'll see full compressor potential in a 7cm turbine housing

However, for the cost of the compressor, the TD06H turbine, the turbine clip, and the machining you're probably better-off just choosing something that is already proven. Something else to consider would be the lag- many FP DSM Red users report full boost at 4500+; expect the 25G to be at least that laggy, if not more.

I believe the 25G is rated around 60 lb/min with no hard evidence of DSM logging these numbers with a TD06H turbine in a bolt-on housing, so in the end it would be a roll of the dice when we already have a fair amount of turbos available capable of producing airflow in the area of 60 lb/min which will definitely spool quicker.

Something to keep in mind when experimenting with new wheel combinations for turbos being used on cars that have been around 20+ years...if the results are going to be groundbreaking, it's probably already been done.

 

[donniekak]

Must be nice! Can you describe you oiling system a little? Oil feed, OEM return?, oil cooler, still the original brass thrust? Thanks.

Stock 1g oil feed from the head, stock return line, stock turbo internals, and a 1990 oil cooler. This is at 30+ psi on e85, no issues. I run only vr1 20w-50 synthetic, and have never had an oiling issue, or oil related failure.