[Xdrive35i2014]

Anyone has the speed tech stage 3 kit with the EFR 8374 turbo installed? Twisted Tuning has specified "moderate subframe modifications" required. Anyone know what kind of subframe mods exactly and could a local BMW specialist do these mods?

[Kevin39]

I was under the impression that you didn't have to cut anything on F series cars. At least on the 335 anyways but Justin @Twisted would know for sure. Just reach out to Speedtech and I'm sure they'd be able to explain it.

[Xdrive35i2014]

Originally Posted by Kevin39

I was under the impression that you didn't have to cut anything on F series cars. At least on the 335 anyways but Justin @Twisted would know for sure. Just reach out to Speedtech and I'm sure they'd be able to explain it.

The F30 does not need any modifications but subframe modifications are required for E series 335i. My car and a E series 335XI is 99% identical...

I already have a shop lined up to take on the work but I just want to see if anyone here has actually got a 8374 turbo in their E series 335XI so I can know what to expect before dropping some serious cash...

[Kevin39]

Gotcha. I didn't know what car you had. It's not in the post and signatures and all that stuff don't show up on mobile view. I saw a guy on another forum was going to do it. If I run across him again, I'll send you the link.

[Turbod]

My opinion is to just go with the 7670. If you're not worried about the engines longevity I would at least be worried about the transmission and transfer case. Adding that to the extra cost and modification needed to fit the 8347 just doesn't make sense to me.

[Xdrive35i2014]

Originally Posted by Turbod

My opinion is to just go with the 7670. If you're not worried about the engines longevity I would at least be worried about the transmission and transfer case. Adding that to the extra cost and modification needed to fit the 8347 just doesn't make sense to me.

My power goal is around 450whp on low boost (15-17 psi) on pump gas only. I dont think the transmission and the transfer case is a concern yet... For reference, my car is currently at around 370 whp with my mods and around 275 whp baseline on the same dyno.

My rational for the 8374 is pretty much "go big or go home". I already have a PS2 turbo and if i were to do another turbo upgrade, i want the best. I just hope Justin can drop by and clarify what moderate subframe modifications would entail so i can make an informed decision.

[biz77]

This is the wrong turbo for your goals. A 7670 will get you 450AWHP easily with less than 20 psi. The bigger turbo is just going to give you more lag/less spool.

Your "go big or go home" philosophy is akin to someone going out and buying a Kenworth semi truck to tow a 5,000 LBS boat a few times a year.

[Xdrive35i2014]

Originally Posted by biz77

This is the wrong turbo for your goals. A 7670 will get you 450AWHP easily with less than 20 psi. The bigger turbo is just going to give you more lag/less spool.

Your "go big or go home" philosophy is akin to someone going out and buying a Kenworth semi truck to tow a 5,000 LBS boat a few times a year.

From what i have read, the 8340 will spool only a little bit slower versus the 7670. The advantage of the 8340 is that it can achieve higher HP at lower boost of which is very important for me as I am planning to run pump gas only. 450whp at 15-16psi is what I am looking for and I think the 8340 would allow me to reach this goal easier even if it means slightly slower full spool speed.

I don't really understand the semi truck analogy. My other car is a M6 that I drive to work once or twice a week and I can't always make full use of its 500+ horsepower on the street. I can only do 1-2-3 at full throttle on a highway and ease off ... For bumper to bumper traffic applications, a corolla would be superior but I would still prefer my M6 as it is what I want. The 8340 is what I want in my car.

Regardless thanks for your inputs.

[mnstr]

Hi everyone! I was waiting this moment since I got my X5. And now I'm happy to announce you all my MNSTR car coming to life. It's going to be the fastest BMW X5 N55 E70 in the world. Me and my crew are expecting to hit 700+hp. All the details, dyno results, more photo and video, will be posted very very soon. Stay tuned.

https://www.bimmerpost.com/forums/sh...php?p=23703561

[deemarr 335i]

Wow that's awesome bro, first x5 I've seen with a big turbo

[Xdrive35i2014]

Damn bro, that's nuts. Do you have a speedtech stage 3 in there?

I can't wait for videos of the X5! What's your complete mod list?

[mnstr]

Originally Posted by deemarr 335i

Wow that's awesome bro, first x5 I've seen with a big turbo

Thanks a lot.

[mnstr]

Originally Posted by Xdrive35i2014

Damn bro, that's nuts. Do you have a speedtech stage 3 in there?

I can't wait for videos of the X5! What's your complete mod list?

Yes it's Speedtech stage 3. I love their setup. Very soon I'll made new post all about turbo upgrade.