Turbo lag?
#1
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So my new setup is with an SR20 (.80/.64) T25, begi mani, FM cast dp. My spool seems slow, especially compared to my previous setup- ebay mani/dp, .48/.49 DSM T25. Car has 1.6L, 2.5 inch exhaust, test pipe, BTW.
New setup spool: 11 psi at ~3500 rpm
Old setup spool: 11 psi at ~2700 rpm
The numbers above were checked by pulling in 5th gear, just to reduce factors like timing/fuel/etc.
I just rebuilt the SR20 turbo with the kit from gpopshop, but the compressor wheel showed a tiny bit of damage (slight bends at the inducer blade corners).
Is this the reason for the turbo lag, or is this considered normal spool for this turbo?
New setup spool: 11 psi at ~3500 rpm
Old setup spool: 11 psi at ~2700 rpm
The numbers above were checked by pulling in 5th gear, just to reduce factors like timing/fuel/etc.
I just rebuilt the SR20 turbo with the kit from gpopshop, but the compressor wheel showed a tiny bit of damage (slight bends at the inducer blade corners).
Is this the reason for the turbo lag, or is this considered normal spool for this turbo?
#8
Boost Czar
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In the multiple setups I've seen with that turbo, it seems very on point. The larger a/r allow for better top end with a slightly slower spool than a .493 a/r housing T25. Enjoy the top end and enjoy the traction.
#9
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Tom when you say "~500 diff in spool" - do you mean onset of spool? The blue is first out of the gate at <3250 but the red pwns everything else. Can't imagine the red is the smaller AR given the power difference... boost levels the same right?
bryantaylor- any spool plots? specs on the t3/t4?
bryantaylor- any spool plots? specs on the t3/t4?
#10
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Right, bad example as it was the first convenient one I could find with the same turbo/same car in a quick search, but I do believe that the red is the smaller A/R, but at much higher boost. Just trying to note that the diff A/R tends to shift the whole curve and could account for most of his spool difference.
#13
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Also, the wastegate I have is the original actuator at around 10 psi or so. I do have a MBC that is set at 14 psi right now, and it doesn't seem to help spool much if at all. In regards to boost onset, I would think that a MBC would override a bad wastebate actuator...
Last edited by soulcarving; 07-02-2008 at 01:37 PM.
#16
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i dont have any plots, it get a couple of pounds starting at about 3k, but not fully spooled till after 4k, but when it does get fully spooled it hauls ***!
its just a regular turbonetics t3/t4, bought it second hand, but i assume its a 57 trim.
its just a regular turbonetics t3/t4, bought it second hand, but i assume its a 57 trim.
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