Turbo lag?
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? |
.80 exhaust A/R...
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That does seem a couple hundred RPM slow. What WASTEGATE ACUTATOR are you using and it set properly?
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my spool-up sucks.
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I get 11 psi at like 3700 rpm.. stop bitching haha.
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12 psi @ 3200 rpm and i'm running a t3... you either have a leak (exhaust pre turbo or boost) or a crappy wastegate. i'm pretty sure you should spool faster than that.
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1 Attachment(s)
Originally Posted by y8s
(Post 278116)
.80 Exhaust A/r...
First example I could find and not a miata but here is the same turbo on the same car only changing the exhaust housing from A/R 0.63 to 0.82. ~500rpm diff in spool. |
Originally Posted by cardriverx
(Post 278180)
I get 11 psi at like 3700 rpm.. stop bitching haha.
Originally Posted by Arkmage
(Post 278191)
i'm pretty sure you should spool faster than that.
Originally Posted by brgracer
(Post 278254)
+1 While the two turbos are similarly sized, they have completely different A/R that will affect spool.
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. |
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? |
Originally Posted by m2cupcar
(Post 278262)
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?
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two dynos with said turbo....
http://www.boostedmiata.com/dyno_day...plots/lars.jpg http://www.boostedmiata.com/dyno_day...am_samnavy.jpg is nature of the turbo. |
Originally Posted by y8s
(Post 278116)
.80 exhaust A/R...
its a .64 exhaust housing, fwiw. :) |
Originally Posted by brgracer
(Post 278254)
+1 While the two turbos are similarly sized, they have completely different A/R that will affect spool.
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... |
Try a helper spring on the wg arm - that reduced spool on my internally gated t3/t4 3-500rpm across the board.
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Originally Posted by soulcarving
(Post 278354)
I can't imagine guys running GT28's or larger.
http://www.boostedmiata.com/dynos/sc...with_boost.jpg :rofl: |
Originally Posted by m2cupcar
(Post 278262)
bryantaylor- any spool plots? specs on the t3/t4?
its just a regular turbonetics t3/t4, bought it second hand, but i assume its a 57 trim. |
Once I get my 60 trim running I'll try to do a comparison between a .48 and .63 exhaust housing. All I have are .48 housings, but I'll snag a .63 off ebay or something. Why would you even want such a large exhaust housing on a 1.6?
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Originally Posted by zoom2zoom
(Post 278497)
Once I get my 60 trim running I'll try to do a comparison between a .48 and .63 exhaust housing. All I have are .48 housings, but I'll snag a .63 off ebay or something. Why would you even want such a large exhaust housing on a 1.6?
So it sounds like I'm spooling like I should. I'll try the helper spring though. I suspect that I'll have to get a 3" exhaust and EBC. Anything else that helps spool? |
Originally Posted by soulcarving
(Post 278511)
Anything else that helps spool?
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