Technical Hydra Performance 135 Leichtbau State of the Art Thread

Oct 3, 2018
25
I should've read the title lol. I have a 3 series not 1er. Please disregard any stupidity on my part. Always like to hear the reasoning behind things. I would've never thought about a longer contact patch, only wider. So thanks!
 

langsbr

Lieutenant
Apr 5, 2017
746
I can't see that pumpkin will be anything above positively miserable to drive. The stock 3.08 is already poorly matched to a FBO car, let alone one with more power.

Personally, I'm swapping to a 2.56 rear.
I know people said the same about switching to a 3.46, but in practice they said it wasn't bad at all. I couldn't imagine driving a 2.56 in regular traffic. 3.91 would be a bit much for me, but the added redline will definitely help. I prefer keeping max revs down, so 3.46 is about it for me. I'll probably just use a 3.15 M3 diff and call it a day.
 

Hydra Performance

Corporal
Platinum Vendor
Jan 31, 2017
181
Having tried both 3.08 and 3.46 diffs, I'd say the latter is the hands down winner for all round use on a 6MT car revving to 7k, stock turbo or otherwise. I feel the 3.08 is more economy-oriented than is ideal, and the 3.46 to be a more natural fit. With that said, raising the redline to 8k shifts the goalposts somewhat, necessitating a similar % change in gearing.
 

doublespaces

Administrator
Oct 18, 2016
6,761
AZ
From where does the 3.91 come from? You have a knack for obtaining little known and relatively rare items, I'm curious which vehicle you've sourced this from.
 

Hydra Performance

Corporal
Platinum Vendor
Jan 31, 2017
181
E53 X5 4.8is and 6MT 3.0d only, both pretty rare beasts.
I also managed to score a rear driveshaft half with the correct 86mm diff coupling that is of very similar length to stock, but with a female spline connect. I will figure out a way to make it all work and report back ASAP.
48906487_211509886444910_8770610268276260864_n.jpg
 
Dec 1, 2016
214
New York
I like what you're doing (trying new things) but this car is never going to get off the line. Twin turbos designed to make gobs of low end torque and you are running 3.91 gears? Yes, I get that spinning out to 8100rpms still lows you to hit 60+mph in 2nd gear, but, you're going to be spinning 1-3rd all the way to redline. Especially so with your wheel and tire setup.

I'd think that with the turbo setup and power curve you've spec'd this car out for you would've been looking to keep stock gearing or go taller even. Max speed in each gear is only one part of the story. You need the formulas/analysis of WHP/rpm in each gear too.
 
Aug 11, 2017
1,666
Virginia
I don't care for much of the widebody hacks I've seen people do, but that's a matter of taste. So curious what's the max tire one can reasonable run on the E82? E90? Curious ...

Filippo
 
Nov 3, 2016
207
Aston pa
I like what you're doing (trying new things) but this car is never going to get off the line. Twin turbos designed to make gobs of low end torque and you are running 3.91 gears? Yes, I get that spinning out to 8100rpms still lows you to hit 60+mph in 2nd gear, but, you're going to be spinning 1-3rd all the way to redline. Especially so with your wheel and tire setup.

I'd think that with the turbo setup and power curve you've spec'd this car out for you would've been looking to keep stock gearing or go taller even. Max speed in each gear is only one part of the story. You need the formulas/analysis of WHP/rpm in each gear too.
launch in 2nd, the problem is the m/t just has horrible ratios. its just never going to work well drag racing
 
Dec 1, 2016
214
New York
launch in 2nd, the problem is the m/t just has horrible ratios. its just never going to work well drag racing
I disagree as 99% of the issue is stock twin turbos being tuned to make 500wtq+ at 3000rpms but lets not derail OPs thread... It's all speculation without seeing a gear-by-gear dyno showing where the car is making power with his new twin turbo setup.
 

Hydra Performance

Corporal
Platinum Vendor
Jan 31, 2017
181
I like what you're doing (trying new things) but this car is never going to get off the line. Twin turbos designed to make gobs of low end torque and you are running 3.91 gears? Yes, I get that spinning out to 8100rpms still lows you to hit 60+mph in 2nd gear, but, you're going to be spinning 1-3rd all the way to redline. Especially so with your wheel and tire setup.

I'd think that with the turbo setup and power curve you've spec'd this car out for you would've been looking to keep stock gearing or go taller even. Max speed in each gear is only one part of the story. You need the formulas/analysis of WHP/rpm in each gear too.
You're looking at the glass half-empty here. Think of this as a close-ratio dogleg 5-speed (as was en vogue back in the 70s and 80s) instead of a regular plain-jane GS6-53BZ . Traction has always been atrocious on my car below ~100kph regardless of gearing, so I'll just dial the boost down to something like 11psi in 2nd (effectively 1st) and 17psi in 3rd (effectively 2nd) and call good. At the end of the day the maximum possible acceleration is traction-limited and has little to do with any given combination of boost and gear ratio.

I don't care for much of the widebody hacks I've seen people do, but that's a matter of taste. So curious what's the max tire one can reasonable run on the E82? E90? Curious ...
Filippo
275-285 is the widest that can be squeezed on the rear of a narrowbody 1er with ~ET58 rims, trouble for me is that 275/40/17 isn't such a popular size anymore.

I thought the 328xi AT cars all had 3.91 diffs as well
188K not 215K (medium-case not large-case)
 
Last edited:
Jan 29, 2018
99
You're looking at the glass half-empty here. This of this as a close-ratio dogleg 5-speed gearbox (as was en vogue back in the 70s and 80s) instead of a regular plain-jane GS6-53BZ . Traction has always been atrocious on my car below ~100kph regardless of gearing, so I'll just dial the boost down to something like 11psi in 2nd (effectively 1st) and 17psi in 3rd (effectively 2nd) and call good.


@Hydra Performance wait are you saying your looking to run a Dogleg G265/5:hearteyes:?!?
 

Hydra Performance

Corporal
Platinum Vendor
Jan 31, 2017
181
No, just that GS6-53BZ + 3.91 final drive effectively = dogleg close-ratio 5speed, with better gearing than an old-school G265/5 actually :)
 
Oct 28, 2017
830
Monroe CT
I have 275 on a e92 and could prob go 295 or 305 if I got rid of my sdc f14s.
I know this is a 1er but someone asked about a e9x as well.
Also my turbos are getting delivered today I can't wait for the you spent how much on those things from the wife lmao
 
Aug 11, 2017
1,666
Virginia
Our Hydra Performance shipment arrived today. I had it sent to @[email protected]'s shop since he's the head geek. I personally had fun watching the DHL shipment bounce from Beirut -> Bahrain -> Heathrow -> NYC -> Washington DC. It was the adult equivalent of NORAD's Santa Tracker.

I'll defer to Barry since all I saw was photos,. Thanks to Omar for checking in today for its arrival, being speedy on the shipping, and having been so responsive in conversation - he probably has blisters on the tips of his typing fingers.

All of this will get first mocked up on the N54 on the stand. We asked for the intake setup without finish since we intend to possibly mess with it given its Z4 final resting location (nothing ever seems to translate directly to the Z4 so ...)

Filippo
1 box.jpg 1a box.jpg 2 turbo.jpg 3 turbo.jpg 3a turbo.jpg 4 hp vs stock.jpg 4a hp vs stock.jpg 4b hp vs stock.jpg 5 shield.jpg 6 intake.jpg
 
Last edited:
Oct 28, 2017
830
Monroe CT
What outlets are you guys going to run with your hydra turbos I gave vtt silicone and am wondering if I should upgrade and to what if I do.
 
Jul 3, 2018
331
Our Hydra Performance shipment arrived today. I had it sent to @[email protected]'s shop since he's the head geek. I personally had fun watching the DHL shipment bounce from Beirut -> Bahrain -> Heathrow -> NYC -> Washington DC. It was the adult equivalent of NORAD's Santa Tracker.

I'll defer to Barry since all I saw was photos,. Thanks to Omar for checking in today for its arrival, being speedy on the shipping, and having been so responsive in conversation - he probably has blisters on the tips of his typing fingers.

All of this will get first mocked up on the N54 on the stand. We asked for the intake setup without finish since we intend to possibly mess with it given its Z4 final resting location (nothing ever seems to translate directly to the Z4 so ...)

Filippo
View attachment 21149 View attachment 21150 View attachment 21151 View attachment 21152 View attachment 21153 View attachment 21154 View attachment 21155 View attachment 21156 View attachment 21157 View attachment 21158
Awesome, turbos look beautiful! Congrats @fmorelli and @Hydra Performance. Looking forward to the end result!
 

langsbr

Lieutenant
Apr 5, 2017
746
What outlets are you guys going to run with your hydra turbos I gave vtt silicone and am wondering if I should upgrade and to what if I do.
Can you even run the vtt silicone outlets with these? I thought vtt only had 1.5" outlets and these use 2" outlets don't they?
 

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