I sold my vmp blower and I have a good bit of cash saved up. Should I buy a local used HP twin turbo kit with 62mm BB turbos or piece together my own single turbo setup? Looking to run mid to low 8's in the quarter.
I can buy the used HP performance kit Monday for $6,000 that comes with everything except for the intake manifolds and the mid pipe/ catback because I want to run open downpipe anyway. I would run a Sullivan lower intake and a edelbrock upper with a 90mm foxbody accufab tb. I already have the 1400hp return fuel system, built TH400 and SRA. Also I have a 4.6 with 10.5:1 compression, ported heads and custom grind cams. Running a scavenger pump and oil restrictors is what makes me think just going with a big single with cg fab hot side. I'll post a pic of the HP kit on the owners carThat kit can get you 1000whp, and modifying it can get you to 1100+. It depends on the price. It's a decent kit but needs a lot of "massaging" or rather reengineering to work well at 20+psi... it has flow issues with bigger boost.
What intake manifold do you plan to run? Or rather what rpm window do you want to make power in? If you want low end to 6500rpm power, 60's is a better route on a 4.6. I have 62's on a 5.3 and they take a sec to warm up haha. My head and cam combo is largely to blame though but it's built for revving. Trade offs.
Piecing a kit with Calebs forward facing headers and running 62's if you'll be revving it high will make 1200-1300+ which can propel 6's honestly.
You only need about 900whp to run deep 8's in a sorted car. Get 60's to the 1.30-1.35 range and it'll do it with less than 900whp in a 3400lbs terminator.
If you plan to stay under 7500, a pair of 60's will hit a little faster and work overall better assuming a big A/R to get the top end flow out of them. It's easier to make power with modular by revving them out. A well ported c head with a stage 2 cam and a Sullivan running 62's would be a nice 7500-8000rpm setup with a standalone and e85.
I did a custom 62/65 setup with stage 3 fgt heads, aggressive cams knowing I'll spin it to 8500 soon enough with e85 and a standalone. It's a 5.3 though so I did a bit bigger on the head work to fill the space.
Honestly a destroked 4.6 at 9000rpm would need very little boost to make great power if setup right but it would be a peaky little skittle. Would last a long time though at that displacement unless it was just raced every 1/4 at a time, maybe a season or 2 if so.
Any way you go, plan $15k and be happy if it comes out any cheaper. Fast and reliable is a fools game but trying to do it on a reasonable (given the components) budget almost always yields more reliability.
If you do plan to rev it high, get the full mmr billet timing guides, reversed passenger cam gear, new oem chains, billet trigger/reluctor wheel, lash adjusters etc. It will slipp timing a few degrees every 500 miles if you don't...