What boost are you running?
Originally posted by gq_626
7psi with stock fuel system. I am retarding timing as well with the eManage.
7psi with stock fuel system. I am retarding timing as well with the eManage.
Why is it the tt system comes with 5.5psi yet the vortech puts out 7-8 out of the box? Basically im trying to understand how our motors can handle the vortech/ati boost, so why not 8 psi on the greddy?
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freezeg35: There are a couple of things to keep in mind.
a) Vortech SC comes with a timing retard with the split second box I think. The Greddy has no timing control therefore is kept at 5.5 psi.
b) At 8 psi with stock fuel set-up it will not have enough fuel pressure on through redline. The SC won't reach full boost until redline but a TT will hit full boost faster. I'm not sure if any SC guys are seeing the same behaviour, where there is not enough fuel at redline.
georgiaboy, GQ_626 has no problem yet. Just that he can't boost more as the fuel pump has reach it's limits.
As for me, i'm still at the stock 5.5 psi but will be working on turning up the boost soon. Once I address timing, and more fuel.
a) Vortech SC comes with a timing retard with the split second box I think. The Greddy has no timing control therefore is kept at 5.5 psi.
b) At 8 psi with stock fuel set-up it will not have enough fuel pressure on through redline. The SC won't reach full boost until redline but a TT will hit full boost faster. I'm not sure if any SC guys are seeing the same behaviour, where there is not enough fuel at redline.
georgiaboy, GQ_626 has no problem yet. Just that he can't boost more as the fuel pump has reach it's limits.
As for me, i'm still at the stock 5.5 psi but will be working on turning up the boost soon. Once I address timing, and more fuel.
gboy....350now is correct. The SC builts boost, and sucks up fuel in a slow and controlled manner. This put different demands on the fuel system that the TT. Said another way, the Greddy needs more fuel pressure much sooner in the powerband becuase it reaches max boost sooner...so it taxes the fuel system more than the SC. Also, I believe the Vortech and ATI come with AUX fuel pumps to keep pressure up as boost and RPM increase...so they are getting all the fuel they need.
Also note, that at 6psi, the Greddy kit makes about as much peak WHP as the Voretch and ATI kits at about 8psi or so...dont know the exact numbers, but I think you get my point. Since there is no parasitic WHP loss, the TT's will make more peak WHP than an SC at a given max psi level. I think the PE kit makes even more WHP at given psi level than the Greddy kit, because the PE turbos are more efficient at the presribed boost level than the Greddy turbos. The Greddy's turbos are big...and are not quite as efficient at the lower boost levels as the PE's turbos. Hope this makes sense. Essentially, PSI is just one element to look at when comparing WHP levels.
Also note, that at 6psi, the Greddy kit makes about as much peak WHP as the Voretch and ATI kits at about 8psi or so...dont know the exact numbers, but I think you get my point. Since there is no parasitic WHP loss, the TT's will make more peak WHP than an SC at a given max psi level. I think the PE kit makes even more WHP at given psi level than the Greddy kit, because the PE turbos are more efficient at the presribed boost level than the Greddy turbos. The Greddy's turbos are big...and are not quite as efficient at the lower boost levels as the PE's turbos. Hope this makes sense. Essentially, PSI is just one element to look at when comparing WHP levels.
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