[B58SP]

So I am doing the GC turbo and will be running it with my TU pump. I am reading that for E mixes and max power another HPFP is reccommended. At the moment I am not looking to upgrade that again.

Does anyone know what is the max E85 % that can be safely run with this set up? E30? E40? Any idea on power gains?

[luca10]

Originally Posted by B58SP

So I am doing the GC turbo and will be running it with my TU pump. I am reading that for E mixes and max power another HPFP is reccommended. At the moment I am not looking to upgrade that again.

Does anyone know what is the max E85 % that can be safely run with this set up? E30? E40? Any idea on power gains?

I would love to know as well. I also have the b58tu pump looking to do with gc turbo

[Jay5k]

Check JD11937's comments
https://f30.bimmerpost.com/forums/sh....php?t=1753093

He is running gc turbo, Dorch stage 1, 22-23psi, 15-16 degrees of timing, e40. high reading dyno, 610whp / 620tq. closer to 540-550. Also x-drive. So a little less for the TU pump

[Glemm1970]

My Dorch 1 does not pull the E30. The pressure drops at a maximum torque of 4-4.5 rpm. It is clear that this can be corrected by setting the firmware, but there is no fuel reserve for this turbine on the TU, Dorch 1 pumps. You need Dorch 2 and the like. Then the E50 can also be cast.

[ryanjorunner]

It seems like it depends on how aggressive the tune is in the mid range. With E30 I'm sure your tuner can limit boost in the mid range and roll it on above 5k or so. You'll leave some power on the table at lower rpms but the TU pump shouldn't be a limiting factor up top.

Similar to stock pump stock turbo e30 tunes, you can't run full boost until around 5k+ thus the difference in mid range between the OTS E30 Stg 2 and E30 Stg2+ tunes from MHD and BM3.

Upgrading to Dorch 2 or similar should allow you to run full boost ASAP on E30+ or run E50-E85 and make more up top as well.

[B58SP]

Originally Posted by ryanjorunner

It seems like it depends on how aggressive the tune is in the mid range. With E30 I'm sure your tuner can limit boost in the mid range and roll it on above 5k or so. You'll leave some power on the table at lower rpms but the TU pump shouldn't be a limiting factor up top.

Similar to stock pump stock turbo e30 tunes, you can't run full boost until around 5k+ thus the difference in mid range between the OTS E30 Stg 2 and E30 Stg2+ tunes from MHD and BM3.

Upgrading to Dorch 2 or similar should allow you to run full boost ASAP on E30+ or run E50-E85 and make more up top as well.

That's basically answer I was looking for thanks. Not looking for a crazy ass tune considering that I will already be making more power than stock turbo regardless. Eventually I'm sure that I'll upgrade HPFP again

[JD11937]

With dorch stage 1 with gc turbo I will see some drops in rail pressure, primarily in third gear at peak torque rpm. I've only noticed this recently as I've been logging and thanks to a user here pointing it out on one of my logs. I've already ordered stage two pump to be safe. I was also trying to push my ethanol content a little higher than e40 but clearly stage one won't cut it.

[Glemm1970]

I will also wait for Dorch 2. If you programmatically remove boost 3200-4400, then the car does not get a pleasant jerk from the very bottom, and all boost above 4500 rpm at the top is not always needed. With a TU pump at 3100-4400 the boost rises from 17 to 19psi, then at 4400-6700rpm 19-21psi. If there is a Dorch 2, the boost will be 21-22psi directly from 3300 to 6800rpm. Turbine GC fuel 100Ron. On the E30 / 40 it will be even more fun and sharper to inflate. Need fuel)) and I think the pump in the tank is also desirable to change.

[kern417]

If you guys are seeing pressure drops then you need a new tuner. There's absolutely no reason why a turbo can't be tuned around a fuel pump's limits at any ethanol blend.

It's the same way we have a stage 2 tune for stock hpfp and stage 2+ for the TU pump. It's not that you can't run the stock turbo without a TU pump, but you run less boost to work around the fuel pump's limits.

[B58SP]

Originally Posted by kern417

If you guys are seeing pressure drops then you need a new tuner. There's absolutely no reason why a turbo can't be tuned around a fuel pump's limits at any ethanol blend.

It's the same way we have a stage 2 tune for stock hpfp and stage 2+ for the TU pump. It's not that you can't run the stock turbo without a TU pump, but you run less boost to work around the fuel pump's limits.

THIS

[Jay5k]

Originally Posted by kern417

If you guys are seeing pressure drops then you need a new tuner. There's absolutely no reason why a turbo can't be tuned around a fuel pump's limits at any ethanol blend.

It's the same way we have a stage 2 tune for stock hpfp and stage 2+ for the TU pump. It's not that you can't run the stock turbo without a TU pump, but you run less boost to work around the fuel pump's limits.

What about top end? What is the limiting factor for cranking up the boost if running something like E40 and the pump (dorch s1) holds rail pressure? Is it octane and knock resistance?

Would I be able to run like 24-25psi up top?

[weehe126]

Originally Posted by Jay5k

What about top end? What is the limiting factor for cranking up the boost if running something like E40 and the pump (dorch s1) holds rail pressure? Is it octane and knock resistance?

Would I be able to run like 24-25psi up top?

You should be able to.

[G.Newt]

Originally Posted by kern417

If you guys are seeing pressure drops then you need a new tuner. There's absolutely no reason why a turbo can't be tuned around a fuel pump's limits at any ethanol blend.

It's the same way we have a stage 2 tune for stock hpfp and stage 2+ for the TU pump. It's not that you can't run the stock turbo without a TU pump, but you run less boost to work around the fuel pump's limits.

+100000
What's the point in paying for a "custom" tune if it's not bespoke for your mods lol.

[kern417]

Originally Posted by Jay5k

What about top end? What is the limiting factor for cranking up the boost if running something like E40 and the pump (dorch s1) holds rail pressure? Is it octane and knock resistance?

Would I be able to run like 24-25psi up top?

You'll need to work through that with your tuner. Based on the data we've seen from Pure, the TU pump works best at E30 when maxed out. It allows the best blend of peak boost and timing. It should be similar for other pumps. E40 is nice because it's basically an even 50/50 split between E85 and pump gas, so a lot of people go that route.