Where is the 'cast' or GC N54 upgrade advantage? Timeslips show no gains

[Sticky]

We've seen 108mph 1/8 mile and ~135mph 1/4 traps from a near full weight E82 @26-27psi on modified OEM turbine housings (Super RB EVO's)

Wait, where was that 135 Super RB slip?

[Sticky]

Yes sir the point is that none of these "high power" offerings seem to be doing much better than the other towards the higher power ranges in the real world, all seem to be hovering around the same area EVEN with "game changing" housings.

This pretty much sums the point up.

Somehow they make way more power on the dyno of the guy selling them but not the strip. Don't even think of asking for runfiles to try to explain it.

[Rob@RBTurbo]

Wait, where was that 135 Super RB slip?

Here is the 108.xx MPH 1/8- will have to find the ~135mph slip later. This one wasn't his best 1/4 trap, but this was extremely impressive as most of these setups never seem to top 102-103mph in the 1/8th:
https://www.bimmerboost.com/showthre...8-4-in-the-1-8!
Unfortunately he only picked up 25mph on the back half on this pass, whereas a stronger "star aligned" backend performance this one would've netted a 137+mph trap.

Rob

EDIT: Here is another one with a 133.xx mph trap: https://www.bimmerboost.com/showthre...3-1-4-mile-run
Will have to text him to see if that was his best. Was pretty sure he had a 134.xx pass, may have not had the best ET however.

At the end of the day none of these cars are easily skating their way into the 133+mph range on any of these turbos offered today ("cast" or not). This particular car above made ~610rwhp IIRC on an apparently trustworthy dyno, which is another point as some make 700+rwhp on their respective dynos and then can barely eek out a 130+mph trap. IMHO these setups running 130+mph is likely beating all the hardware way too much, simply not worth stressing the components as such at that point. Possibly ok for an event but not realistic for the everyday/longterm.

[Sticky]

This one wasn't his best 1/4 trap, but this was extremely impressive as most of these setups never seem to top 102-103mph in the 1/8th:
https://www.bimmerboost.com/showthre...8-4-in-the-1-8!

I remember that, highly impressive run.

I just saw 135 and was thinking I never remember seeing a trap that high for Super RB's.

[Sticky]

At the end of the day none of these cars are easily skating their way into the 133+mph range on any of these turbos offered today ("cast" or not). This particular car above made ~610rwhp IIRC on an apparently trustworthy dyno, which is another point as some make 700+rwhp on their respective dynos and then can barely eek out a 130+mph trap. IMHO these setups running 130+mph is likely beating all the hardware way too much, simply not worth stressing the components as such at that point. Possibly ok for an event but not realistic for the everyday/longterm.

Strongly agree. At that point, it may be time to look past stock frames.

[Rob@RBTurbo]

Strongly agree. At that point, it may be time to look past stock frames.

Stock Frames, Chinaframes, Gamechanger frames, etc.

[AWSAWS]

Well it'd be interesting to flow test a GC turbo, mmp turbo and stock turbo.
The point about post turbine iats is very important. So is the back pressure.
I'm sure though if I try and flow more air through the same volume of tube (charge pipe) then the pressure will rise with the increased resistance. It definitely helps to have larger plumbing before and after the turbos etc. Within limits of course.

When talking trap speeds it very important to consider the fuel used, timing advance and weight of the car etc.