Drive Pressure and Twins Question

bh10

bh10

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Im going to be throwing a set of twins right on my 12v here soon and am worried about Drive Pressure. Im wanting to use my turbo I have on there already a non-wastegated 62/65/14 as the secondary. As for the primary I havent figured out the what size compresser wheel I want to run (either a 75 or 78mm), but Im wanting to run a 83mm wheel, 1.1 a/r on the exhaust, for quicker spool up. Do you think drive pressure's will get out of hand w/ this combo w/out a wastegate, or should I go with a 1.32a/r or an external waste gate?

I fully ported head intake and exhaust w/ a individual runner intake waiting to be installed and once the 180 Ppump I bought gets here its being sent out to get maxed out for a 12mm pump by either Seth on the board or CDS. So I will have quite a bit of fuel, but a good flowing head.
 
If you are absolutely interested in using the 1.1 housing for the fastest spool, throw an external gate between the stages. (you running an external gate on the manifold?) You will have to monitor and tune the gate(s) fairly well, though
 
I was planning on run an E.D. WG at the manifold, if needed.
 
bh10 said:
Im going to be throwing a set of twins right on my 12v here soon and am worried about Drive Pressure. Im wanting to use my turbo I have on there already a non-wastegated 62/65/14 as the secondary. As for the primary I havent figured out the what size compresser wheel I want to run (either a 75 or 78mm), but Im wanting to run a 83mm wheel, 1.1 a/r on the exhaust, for quicker spool up. Do you think drive pressure's will get out of hand w/ this combo w/out a wastegate, or should I go with a 1.32a/r or an external waste gate?

I fully ported head intake and exhaust w/ a individual runner intake waiting to be installed and once the 180 Ppump I bought gets here its being sent out to get maxed out for a 12mm pump by either Seth on the board or CDS. So I will have quite a bit of fuel, but a good flowing head.
Click to expand...

I was planning on something similar...


Chris @ ED and I discussed a few options, but basically what we decided on was to let the internal wastegate do the daily driving duty's, and to let the external open up when romping on it. I was going to gate clear around the primary, since with a 4500RPM 12v, and a 1.10 housing with a 83mm wheel, I didn't think I'd have any trouble staying on top of it.

If need be, I could always re-plumb the wastegate into the hot pipe if needed.


But, now the truck is for sale, the chargers are still coming, and I won't have anything to put them on:D

Chris
 
being that the 74-83 is so restrictive and the 80-87 comes on the like 2 stroke you could always come up with your own specs for the pri turbine

thats what i did

hoping to get away with running only the twin 1" pucks in the 68 that way

will see...

someday...
 
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