[whyzee125]

Hey guys,

I currently run the OG VRSF 7" (non-HD) and it's not enough for my setup and climate.

I'm on stock turbos at 21psi, inlets, PI and full e85. I don't have plans to upgrade turbos until they fail but they're going strong with zero rattle so I expect at least a few more years out of them.

Options I'm considering:

- VRSF 7.5 competition (probably happy medium, but may want more if/when I do upgrade turbos)
- VRSF 7.5 race 1000hp (my first choice; some say too big for stock turbos, ie laggy and high wgdc)
- CXracing / Big Tom (not the most elegant but works very well and looks badass. Had this on a previous N54 and it was great)

Tony from Vargas, from a few of his posts, seems to say just get the largest you can and any downsides will be negligible. I think I agree but I have no firsthand experience particularly with the VRSF 1k hp one, which would be my first choice. What say you?

[iqraceworks]

Why are you saying it's "not enough"? What do your IAT logs look like?

[whyzee125]

Originally Posted by iqraceworks

Why are you saying it's "not enough"? What do your IAT logs look like?

It's pretty easy to get it to 140+ in one or two pulls in the summer.

[iqraceworks]

Originally Posted by whyzee125

It's pretty easy to get it to 140+ in one or two pulls in the summer.

What are the IAT's before, and after a pull? Just trying to see how much heat you are actually building.

[oVeRdOsE.]

wow 140 !

what boost pressure?

[whyzee125]

Originally Posted by iqraceworks

What are the IAT's before, and after a pull? Just trying to see how much heat you are actually building.

When it hits 140 that's starting out around 100 or 105. In the non-summer months I have zero issues

[whyzee125]

Originally Posted by oVeRdOsE.

wow 140 !

what boost pressure?

21psi

[oVeRdOsE.]

Originally Posted by whyzee125

21psi

oh right was in the 1st post...

Are you loggin the temps?

Dman, I only have the 5'' stepped FMIC, 20 psi on a single turbo, and on the many logs I did I never hit 90-ish°F no-boost to light boost, at full boost I'm about 10-15°F lower than 90°F, thanks to the meth kit. hehe

We dont have crazy hot climate, but my last logs for the tuner , we had around 78-85°F thermometer outside, and I was on the highway....
I should check with lower speeds.

What would be a safe limit for my knowledge?
I'm planning to got around 23psi, Ill keep an eye on temps to see if I ''need'' a bigger IC too

[335i54n]

yup, the biggest you can get, but with hot temps, back-to-back multiples pulls and maxing out stock turbos= wmi still a must. Ideally, a m3-style bumper (bigger mouth), the largest fmic, and wmi

[whyzee125]

Originally Posted by 335i54n

yup, the biggest you can get, but with hot temps, back-to-back multiples pulls and maxing out stock turbos= wmi still a must. Ideally, a m3-style bumper (bigger mouth), the largest fmic, and wmi

I run full e85 so I have some cylinder cooling as well, though not quite as much as meth. I don't plan to go that route as it's kind of known that the VRSF 7" isn't that great at super high boost. Most report that IAT's are even if not lower at the end of a pull with the 1000hp units, I just don't know if I should take peoples' claims seriously that say the pressure drop/lag is a big deal.

[oVeRdOsE.]

have you checked the water to air intercoolers mods?

can be a fun project.

[whyzee125]

Originally Posted by oVeRdOsE.

have you checked the water to air intercoolers mods?

can be a fun project.

I saw that lol that's badass but I don't think I have the desire to go that far with it. Honestly 8 months out of the year mine does fine and I know there are way better than what I've got. I'm sure the 7.5 competition would be more than enough but I love the idea of literally never worrying about IATs again and them never even rising during hard driving, which I could achieve with the race one.

CPS makes a race one for even cheaper than VRSF that could be an option. I've been out of the intercooler shopping game a long time lol, ADE is out of business and these new ones are so nice and also cheap

[turbohugh]

I think 21 psi on stock turbos is always going to end up with high IAT. Intercooler wont save you when you're outside the efficiency range of the turbo.

[whyzee125]

Originally Posted by turbohugh

I think 21 psi on stock turbos is always going to end up with high IAT. Intercooler wont save you when you're outside the efficiency range of the turbo.

It's really not, it tapers a bit as it gets higher and I have zero issues except for super hot days in the summer. I don't even have limp mode on track, I just want to be extra careful against timing corrections and make sure I'm not leaving anything on the table when it can be avoided.

[AWD Addict]

Originally Posted by whyzee125

It's really not, it tapers a bit as it gets higher and I have zero issues except for super hot days in the summer. I don't even have limp mode on track, I just want to be extra careful against timing corrections and make sure I'm not leaving anything on the table when it can be avoided.

That's a lot of boost on the stockers, particularly in the summer.

My Summer IATs are high w the stockers, and I'm in Boston w/ an OG 5" IC. I was pulling enough timing last summer, that I dialed back my tune to resolve it.

[whyzee125]

Originally Posted by AWD Addict

That's a lot of boost on the stockers, particularly in the summer.

My Summer IATs are high w the stockers, and I'm in Boston w/ an OG 5" IC. I was pulling enough timing last summer, that I dialed back my tune to resolve it.

I'm in the same boat, I'm running my conservative 15psi 93 oct tune now. Very gentle and low IAT's. But I'd like to resolve it entirely with a huge FMIC lol

[lowrydr310]

I think I saw whyzee ask but nobody answered: any noticeable lag or other adverse affects going with the huge 7.5" race intercooler with stock turbos?

I've been wondering this for a while as I am intercooler shopping. No plans to run anywhere near those levels of boost (limited by 91 octane and stock downpipes) but plans sometimes change, and it gets hot here. Stock intercooler is a joke, even at 70 degree ambient temperatures I see huge IAT increases.

[335i54n]

^i doubt it, only likely to show up in the datalog by a few rpms loss before boost demand met and would be more than offset by cooler iats. overworking the turbo, a fmic can only do so much, even with 60f ambient my water injection is only able to keep iat under 120 when i am really hard on it for a long time

[oVeRdOsE.]

Originally Posted by lowrydr310

I think I saw whyzee ask but nobody answered: any noticeable lag or other adverse affects going with the huge 7.5" race intercooler with stock turbos?

I've been wondering this for a while as I am intercooler shopping. No plans to run anywhere near those levels of boost (limited by 91 octane and stock downpipes) but plans sometimes change, and it gets hot here. Stock intercooler is a joke, even at 70 degree ambient temperatures I see huge IAT increases.

if remote turbo dont produce lag, I doubt on a bigger IC.
other effect, maybe.

here a very clear explanation