hello. im me again. i have my engine running with a 12psi of boots of t28 turbo. but i notice something in my datalogs. map rise to where suposed to be but then map reading falls a little and kept steady in 9psi of boost.
i did some runs and noticed boost gauge read a steady 12psi of boost til 7500 rpms but in datalog it only has 12psi to 5500-6000rpm and then falls to 9psi. and another thing is map reading is a little spiky. what did you do to solve this? i see your datalogs and seems to have same problem with your map reading. and this is a problem because we have a lower timing advance with more kpa reading and highe timing advance with lower kpa readings.
i try the lag factor to 50% but it removes spiky but map reading isnt acurate.
87 Nissan 200SX, SR20DE+T, MS1-Extra
Re: 87 Nissan 200SX, SR20DE+T, MS1-Extra
My map falls off because my small turbine doesn't flow enough, not sure why yours does... A T28 should have a large enough turbine.
The noisy MAP can be smoothed out by placing a small vacuum can inline with your MAP vacuum line, I had one that I made out of PVC coupler and two plugs... I just drilled and tapped them for some 1/8" NPT hose barbs.
The noisy MAP can be smoothed out by placing a small vacuum can inline with your MAP vacuum line, I had one that I made out of PVC coupler and two plugs... I just drilled and tapped them for some 1/8" NPT hose barbs.
Re: 87 Nissan 200SX, SR20DE+T, MS1-Extra
seishuku wrote:My map falls off because my small turbine doesn't flow enough, not sure why yours does... A T28 should have a large enough turbine.
The noisy MAP can be smoothed out by placing a small vacuum can inline with your MAP vacuum line, I had one that I made out of PVC coupler and two plugs... I just drilled and tapped them for some 1/8" NPT hose barbs.
i will try your solution. and the boost gauge reads a steady 12psi of boost. there isnt drop on the boost gauge. problem is the values in map reading. theyre not same.
i have a friend running his t25 to 12psi too without any drop in the boost gauge.
Re: 87 Nissan 200SX, SR20DE+T, MS1-Extra
Hm, not sure why the MS MAP sensor would fall off like that and not the boost gauge... I'm fairly sure my actual gauge falls off too though, it's just not as noticeable.
Of course my T25 needs to be rebuilt too...
Of course my T25 needs to be rebuilt too...
Re: 87 Nissan 200SX, SR20DE+T, MS1-Extra
Well I got the turbo disassembled for rebuild, and apparently my manifold to turbo gasket was partly blown out, so that's probably why my boost was falling off.
What surprises me though, is that it wasn't making any noise like you would expect from an exhaust leak.
What surprises me though, is that it wasn't making any noise like you would expect from an exhaust leak.
Re: 87 Nissan 200SX, SR20DE+T, MS1-Extra
Well that rebuild took way longer than it should have...
Anyway, got it done, and so far so good!
I don't know if it was just a partly blown out gasket before, or if the turbo was just that worn, but boost holds MUCH better now... Pulls like crazy now too, but that might just be because I haven't driven with a turbo in so long.
Anyway, got it done, and so far so good!
I don't know if it was just a partly blown out gasket before, or if the turbo was just that worn, but boost holds MUCH better now... Pulls like crazy now too, but that might just be because I haven't driven with a turbo in so long.
Re: 87 Nissan 200SX, SR20DE+T, MS1-Extra
can you share schematics about bu941 & cops ?seishuku wrote:Building up my coil harness:
Coil drivers, ST BU941P ignition power darlington transistor, I've used them before to replace OEM transistors and had great results. Pretty cheap too.
2-valve modular Ford coils.
Just need to finish soldering the transistors up on the harness, install heat sink, and wire it up to the MS.
Re: 87 Nissan 200SX, SR20DE+T, MS1-Extra
They wire in just like VB941s or BIP373s, but I've stopped using them because they take too much current to drive.
I've since switched to Fairchild ISL9V3040P3, it's a much better devices... Though they don't have any kind of current limiting like the VB or BIP.
BUT it would seem that there's at least one or 2 of those coils were bad or starting to go bad, the engine would idle, cruise, and be fine under light load, but as you get close to 100KPa it would start to misfire.
So, I've picked up some coils for a 2005 Hyundai Tiburon and stripped down the bracket a little:
They're pretty nice, replacement coil pack comes with the full bracket, wire harness (with condenser), and pair of coils.
The coils them selves are made by Denso.
I've since switched to Fairchild ISL9V3040P3, it's a much better devices... Though they don't have any kind of current limiting like the VB or BIP.
BUT it would seem that there's at least one or 2 of those coils were bad or starting to go bad, the engine would idle, cruise, and be fine under light load, but as you get close to 100KPa it would start to misfire.
So, I've picked up some coils for a 2005 Hyundai Tiburon and stripped down the bracket a little:
They're pretty nice, replacement coil pack comes with the full bracket, wire harness (with condenser), and pair of coils.
The coils them selves are made by Denso.
Re: 87 Nissan 200SX, SR20DE+T, MS1-Extra
Cleaned up the plug wires... Still need to clean up the wiring, but I've had it on for some time now and it's been running great!
Now I'm playing around with this:
50 trim T3 from a turbo Saab.
Down pipe, made it as an adapter to mate up to the old T25 cast turbine outlet.
I've since added the O2 bung, but don't have a pic of that.
The manifold is a cast iron log type made by EMUSA, I also got a 38MM wastegate from them as well:
The waste gate is open dump for now, I need to get a flex joint and merge it into the down pipe.
So far I have it up to 10PSI, and it's pulling at least as hard as the T25 at 14PSI... I think 14PSI is going to be my target still, as long as my injectors can keep up.
Now I'm playing around with this:
50 trim T3 from a turbo Saab.
Down pipe, made it as an adapter to mate up to the old T25 cast turbine outlet.
I've since added the O2 bung, but don't have a pic of that.
The manifold is a cast iron log type made by EMUSA, I also got a 38MM wastegate from them as well:
The waste gate is open dump for now, I need to get a flex joint and merge it into the down pipe.
So far I have it up to 10PSI, and it's pulling at least as hard as the T25 at 14PSI... I think 14PSI is going to be my target still, as long as my injectors can keep up.
Re: 87 Nissan 200SX, SR20DE+T, MS1-Extra
Not much going on hardware wise, not until it gets warmer out at least... Been a VERY long and VERY cold winter.
BUT, on the plus side (depending on how you look at it), I've been able to tune cranking, afterstart, and warm up enrichments for temps that I never thought I would have to deal with! (I've attached my current running tune)
Still with the 50trim T3, I've since doubled the pressure to 20PSI, though I try to keep it to around 15PSI.
Still pushing the 528CC injectors to the max, still keeping it safe at 85% though.
I'm hoping to get it on a chassis dyno soon, I really want to find out what I'm making.
BUT, on the plus side (depending on how you look at it), I've been able to tune cranking, afterstart, and warm up enrichments for temps that I never thought I would have to deal with! (I've attached my current running tune)
Still with the 50trim T3, I've since doubled the pressure to 20PSI, though I try to keep it to around 15PSI.
Still pushing the 528CC injectors to the max, still keeping it safe at 85% though.
I'm hoping to get it on a chassis dyno soon, I really want to find out what I'm making.
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