1991 1.6 Greddy
#1
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1991 1.6 Greddy
1991 1.6 M-5 @ 55k miles, Stock ECU, Stock Motor
Greddy turbo kit, Greddy downpipe, original 1.6 midpipe and cat, 2.75" "axle back" duals, Saab 900 i/c, BEGi FMU, 190 lph hp, 1.8 injectors, FM mbc, stock NGK gapped at .035", 13* pulling 6* with MSD
DynoJet, 23% humidity, 65*F, 3rd gear pulls:
6 psi--167 hp, 157 lb/ft
9 psi--185 hp, 160 lb/ft
I left 5 or 6 hp on the table, but wanted to remove a lean spot at 4.5k. I could not improve the fuel curve after 5.5k. I tried opening the BEGi's needle valve, advancing timing, and fooling with the afm clockspring. I could have added more boost and/or timing, but left a substanital safety area.
Greddy turbo kit, Greddy downpipe, original 1.6 midpipe and cat, 2.75" "axle back" duals, Saab 900 i/c, BEGi FMU, 190 lph hp, 1.8 injectors, FM mbc, stock NGK gapped at .035", 13* pulling 6* with MSD
DynoJet, 23% humidity, 65*F, 3rd gear pulls:
6 psi--167 hp, 157 lb/ft
9 psi--185 hp, 160 lb/ft
I left 5 or 6 hp on the table, but wanted to remove a lean spot at 4.5k. I could not improve the fuel curve after 5.5k. I tried opening the BEGi's needle valve, advancing timing, and fooling with the afm clockspring. I could have added more boost and/or timing, but left a substanital safety area.
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I didn't get any files, I didn't know to ask.
#5
your greddy is spooling VERY slow. You need to open up that exhaust man. Other than that it looks really nice...AFR's are rich across the board. The reason you only gained 3-4 ft/lb from 6-9psi is because you are spooling so late and the engine is out past where it would normally make peak tq (4000-4500) open up the exhaust and youll gain like 20whp and 20wtq.
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your greddy is spooling VERY slow. You need to open up that exhaust man. Other than that it looks really nice...AFR's are rich across the board. The reason you only gained 3-4 ft/lb from 6-9psi is because you are spooling so late and the engine is out past where it would normally make peak tq (4000-4500) open up the exhaust and youll gain like 20whp and 20wtq.
The exauhst mani and downpipe are Greddy. The cat and pipes for and aft of it are original 2". And I know that chokes the turbo.
#7
slow compared to other greddy setups. For example...my old greddy setup on 13psi made 230ft/lb and 217whp. That was with a large 15psi spike right around 4200 rpm ( that was full boost ). You can clearly see by your graph that you dont see full boost until around 5200-5500rpm. Thats VERY slow spool that will improve by over 1000rpm with a better exhaust and downpipe.
#9
now dont get me wrong, you have all the fuel well sorted out...but once you open up the exhaust youll run more lean under 4500 rpm. The reason you are around 12:1 right now is because the turbo isnt producing boost that low...so youll need to retune that rpm range...just so you know. But other than that your setup is making the power..it just needs to breathe
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Ahh... I wanted to make sure you thought it was laggy because of the original exauhst components, not because of some other fault hidden to me. I can do bigger pipes And that cat's _only_ 15 years old. You think the mani needs to be ported too eh? I'm sure I can have a machine shop do that for me. Is there anything I need to know? Your guidance is appreciated.
I spent a while studying others' dyno charts. I see where a big exahust will allow 100 hp sub 4k rpm, higher peak torque, and better power curves. I thought my peak tq was a little low.
Thanks
I spent a while studying others' dyno charts. I see where a big exahust will allow 100 hp sub 4k rpm, higher peak torque, and better power curves. I thought my peak tq was a little low.
Thanks
#13
Ahh... I wanted to make sure you thought it was laggy because of the original exauhst components, not because of some other fault hidden to me. I can do bigger pipes And that cat's _only_ 15 years old. You think the mani needs to be ported too eh? I'm sure I can have a machine shop do that for me. Is there anything I need to know?
Your guidance is appreciated.
Thanks
Your guidance is appreciated.
Thanks
The manifold would be just fine as is. Porting it wouldnt really give you any gains..that manifold is what it is. I found that when I took off my stock exhaust the cat was dead, yours could be as well. I bet if you cut out the cat and just welded a pipe in place of it you would spool 600rpm faster on just that alone. if you want to see how fast your car would be w/ a new exhaust take off the old exhaust completely and run open DP, youll love it trust me
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New results, May 17 2007
You can compare this to my earlier 185 dynojet rwhp
Car is the same. Bone stock 91 now at 58k miles, greddy kit, 2.5" dp, RC 440 injectors, DIY dual feed rail, MSPNP w baro correction. Solid line shows the final run with MS EBC activated. The peak boost is a quick 15 psi spike settling to 14 psi. The dotted line is with MBC so you can see the difference.
Car is the same. Bone stock 91 now at 58k miles, greddy kit, 2.5" dp, RC 440 injectors, DIY dual feed rail, MSPNP w baro correction. Solid line shows the final run with MS EBC activated. The peak boost is a quick 15 psi spike settling to 14 psi. The dotted line is with MBC so you can see the difference.
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So why does torque drop after 5600 rpm? Let's look at the datalog:
2250: 1 PSI
3671: 5 PSI
3500: 14.5 PSI
4800: Boost Peak 15.2 PSI
5500: 14.5 PSI, starting to drop
6000: 13.8 PSI
6500: 13.3 PSI
6772 (peak rpm): 13.0 PSI
The decline in tq corresponds directly with the drop in boost. 227 lb ft at 15.2 psi dropping to 200 lbft at 13 psi. If we asked the EBC to hold boost at 15 psi, what would happen? Well, if I had a built motor I could carry more boost to redline and keep the torque curve very flat to redline. The HP curve would contiune on its steep increasing slope, though we're really starting to push the compressor, but there may be 270 rwhp in there. Also, it means that my power numbers with the MSPNP were made at 15psi spike dropping to 13psi. Impressive!
2250: 1 PSI
3671: 5 PSI
3500: 14.5 PSI
4800: Boost Peak 15.2 PSI
5500: 14.5 PSI, starting to drop
6000: 13.8 PSI
6500: 13.3 PSI
6772 (peak rpm): 13.0 PSI
The decline in tq corresponds directly with the drop in boost. 227 lb ft at 15.2 psi dropping to 200 lbft at 13 psi. If we asked the EBC to hold boost at 15 psi, what would happen? Well, if I had a built motor I could carry more boost to redline and keep the torque curve very flat to redline. The HP curve would contiune on its steep increasing slope, though we're really starting to push the compressor, but there may be 270 rwhp in there. Also, it means that my power numbers with the MSPNP were made at 15psi spike dropping to 13psi. Impressive!
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Last edited by Ben; 05-19-2007 at 08:47 AM.