I'm tossing around the idea of upgrading to twins. Just curious what the twin experts think. Maybe a s 475? Or should I sell my 62 and start fresh? Plan on stopping around the 600-650 HP range... probly Im hoping to find a setup that wouldnt make me do a bunch of headwork like valve springs, o-ring etc... I would like to maintain good street manors as this is my daily driver. I tow a 14k lb trailer/backhoe on occasion and 6k lb trailer more frequently in the hills of northern ca. Am I asking for too much with the towing and streetability with those numbers? I do plan on arp 12mm 625 headstuds very soon and my dead HO vp44 is about to be swapped to an so vp. Keep in mind I have a 6 speed w/3.55 gears and 285's

 

With that large of a turbine housing, I'd recommend a larger big turbo. If you're happy with the response you have now, I'd go all the way up to a 480, but that's just me.

The larger the big charger, the bigger its map is and it will generally do the same work more efficiently. Yes, it takes a tiny bit longer to spool, but the role of the big charger in twins response is very small compared to the role of the small charger.

With any big turbo, you will need to downshift to stay ahead of EGT when towing your heavier trailer. If you find that you get hot too easily when towing your light trailer in the hills, it's not the choice of bottom turbo that will cause the problem or fix it-- you'd need a more responsive top turbo.

JH

 

75/83/1.1 t6. Good to go.