Supercharger upgrade for 4AGE--> eaton M90

**nick.parker** · 20-03-2006, 11:05 AM

Hi,
Thats some good power. No my engine doesn't choke at all, its quite good at high revs, but still suffers the regular torque drop off, but less severe than a standard for a GZE...my eventual target (SC14 only) is around 180rwhp. Probably the easy things are a few more PSI (or even then same) and put the 8.9:1 pistons in (or Arias 8.6:1 = a bit safer). It has crossed my mind to use a smallport head too in an attempt to improve low and mid range torque. I think 200rwhp will be a challenge. What setups are you and your friend using? If you want some info on what I have done, check out my home page. (if you haven't already)

Cheers, Nick.

**ToySprinta** · 20-03-2006, 09:36 PM

I'm running a pretty much a standard setup. P&P'd head, bigport cams and larger crank pulley.
Justin's running a sc14 with custom plenum and blow through setup.

**nick.parker** · 20-03-2006, 11:32 PM

Hi,
Is your relatively standard ZE an 8.9:1 smallport or 8:1 bigport?
Cheers, Nick

**pjaw11sc** · 20-03-2006, 11:50 PM

Nick, i only just noticed your edit on the previous page regarding the bypass valve size, i know you said that they use the 'magnussen' on larger setups, but what kind of boost were they running, dont those kinds of set ups on the bigger engines only use a small amount of boost (usually about 10psi) i am just wondering if the bypass would need to be bigger for more boost, as i will be running about 18psi. (Not to doubt what they said i just want to be totally sure its the right one)

**nick.parker** · 21-03-2006, 02:22 AM

Hi,

The bypass has nothing to do with boost on your setup, its purely equalising pressure across the SC at moderate and high vaccuum, to stop that heat build up / rotor expansion issue. Its closed under boost remember! That fact that its used with a bigger blower successfully should negate your concerns.

Cheers, Nick.

**ToySprinta** · 21-03-2006, 05:41 PM

Tis the 8.9:1 small port. PLan on keeping the higher comp too.

**pjaw11sc** · 21-03-2006, 06:49 PM

thanks Nick, i will contact Harrop and ask them for the 'Magnussen'.

**inertia** · 12-04-2006, 11:25 PM

Mr2swift has just released his latest twinscrew dyno run results.

244.02hp ATW

From twincam.org

Here is the latest plot. Did not have time to tune with additional boost so I turned up the fuel and took out some timing. Wanted to play it safe for now at 21psi. Better tune should give some decent curves. What do you guys think?