550hp goal Mk1 Cupra turbo flow rate help!

Leon20vt4

Active Member
Oct 21, 2018
939
683
So... some assholes here in Germany royally pissed me off, shitting on my car because its not a "Cupra R" and only a Cupra... Needless to say I specifically bought my car for the AWD because I can't stand FWD cars. I would've bought a Cupra R if it was possible to get an AWD.

Funny enough there is a Cupra 4x4 2.8 v6 and in switzerland a 4x4 v6 supercharged from the factory (208ps and 265ps) but they are heavy dogs, and impossible to work on.

So now here I sit thinking **** them I will build an engine in my workshop to drop into my 4x4.

I will use a large port head for sure (AGU) or maybe the entire AGU engine.

BUT MY REAL QUESTION IS!!!!

My turbo of choice at 35psi can flow 45-50lbs/min of air and be sitting inside of the 74% efficiency island.

Is this enough to reach 550hp on E85?
I was told that 10lbs/min = 100hp im guessing thats on normal Petrol.

I understand that on e85 you can increase timing because of the cooling effects of the alcohol based fuel. But

First off Im trying to stay as a "smaller" big turbo to keep spool but still flow up top to my 7400rpm redline.

Assuming the AGU flows a 88% Volumetric Efficiency because of the larger port head

(85 for non vvt 4 valve per cylinder engines) (95 for vvt 4 valve per cylinder engines)

AGU is 5 valves per cylinder of course but non vvt (unless there is a conversion i can do???) but with a larger port head than others allowing better airflow.

I know that hp is just a measurement on a dyno and trust me im not building a dyno queen, my turbo or turbos of choice flow extremely well and have a broad and efficient compressor map/ power band. It would just be nice to have a dyno sheet with that 550 number as a goal to hit.

anyone guess my turbo or turbos of choice?
 
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Thai-wronghorse

Self proclaimed Cupra R addict & butcher!
Dec 3, 2015
2,199
1,038
Kent
Looks like it's going to be an interesting thread to watch...

Sent from my SM-G960F using Tapatalk
 

Leon20vt4

Active Member
Oct 21, 2018
939
683
Not the Biggest one out there. But also not the smallest.

Holset Hx30 (400£)

But when it doesn't flow enough I will bump up to an Hx32 (hx30 hot side/hx35 compressor) but those are super hard to find.

So if I cant find one then it'll be an Hy35 but then the boost comes on a bit later than I want. Nothing that a higher rev limit cant fix though!
6305670b79c8eb2b9c59338915b21cef.jpg
 

Leon20vt4

Active Member
Oct 21, 2018
939
683
Contact Bill at Badger5 , he is the ONLY authority on getting high reliable horsepower out of the VAG engines

https://badger5.co.uk/
I feel bad when I'm over here in Germany why waste a man's time that is trying to run a business. I would love to get tuned by him! Just gotta drive a long ways and cross the English channel
 

SlashProm

Active Member
May 23, 2018
160
22
I've been contemplating one for a while, you can pick up an ebay one for around £150, but I'd rather pay the £420 or so for a dbb, not just the spool times, you can see the better quality of turbo, v banded and stuff as standard. I know a GT28-71R would probably be the best all around set up, but if I'm replacing rods, fuel pump, injectors and clutch, why not go a little bit further and slap a 3582 on her :D
 

Leon20vt4

Active Member
Oct 21, 2018
939
683
What about cubic capacity increase ? - there's no substitute for cubes right

1796 -> 1998 or beyond ?
Not off the table but I thought it would be cool to stay in the 1.8 gang.

We say in the US that a turbo just means you're missing cylinders.

No replacement for displacement.
 

Leon20vt4

Active Member
Oct 21, 2018
939
683
Have to be honest I am a "bent 8" kind of guy ........a bit mixed race at that, Ford, Chev & Mopar & Toyota
Only V8 I owned was a BMW 5 liter v8 and a 4.4 also from BMW... beautiful machines. Sounded like a Ford GT when I did res and muffler deletes along with larger intake manifold ...
 

Leon20vt4

Active Member
Oct 21, 2018
939
683
So how much air has to flow from turbo to make 550hp on E85 that's the ultimate question!
 
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