Can I justify headers?
03-07-2006, 08:36 PM
#19
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I have a set of Schnell Headers that I got for my 79 930 project but ended up not using them. Comes with the external oil tank etc... First 600 gets 'em
03-07-2006, 11:46 PM
#20
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Originally Posted by Dave 86 930 Fl
Here is a list of mods I did in the order they were completed:
1 - Larger Intercooler (Andial Sport)
2 - K27-7200 & GHL muffler (big power increase, less lag, good sound)
3 - Air box, fuel head mod, B&B headers, EBC, Tial (.9) - Much more power, huge reduction in lag, great sound. Motor dyno'd @ 422 bhp. Also had the car lowered w/new torsion bars & corner balanced ... car finally looks right and handles much better with out any real road harshness.
1 - Larger Intercooler (Andial Sport)
2 - K27-7200 & GHL muffler (big power increase, less lag, good sound)
3 - Air box, fuel head mod, B&B headers, EBC, Tial (.9) - Much more power, huge reduction in lag, great sound. Motor dyno'd @ 422 bhp. Also had the car lowered w/new torsion bars & corner balanced ... car finally looks right and handles much better with out any real road harshness.
I've got an 87 930 with Kokeln IC, K27, 964 cams, GHL headers and exhaust, Evo intake, no cat, and 1-bar spring. I'm short the fuel head mod and boost control. Any guess what I can hope for at the dyno? I haven't done one yet.
My butt-dyno says that there's a LOT more power from stock but butt-dynos aren't very accurate.
03-07-2006, 11:47 PM
#21
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so B&Bs are better in design that GHLs? I thought it was the other way around. I used to have B&Bs on a Viper and they had issues. Makes me wonder if the 930 B&Bs are same?
87turbo911, its 422hp at crank since you need to figure the drivetrain loss (-.15%) would make his car 496hp (422hp crank/0.85=496.4705hp at wheels)
I don't think the mods he listed will put out 496hp at the crank, unless he's left something out. 150shot of NOS perhaps?
87turbo911, its 422hp at crank since you need to figure the drivetrain loss (-.15%) would make his car 496hp (422hp crank/0.85=496.4705hp at wheels)
I don't think the mods he listed will put out 496hp at the crank, unless he's left something out. 150shot of NOS perhaps?
03-07-2006, 11:47 PM
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Originally Posted by goldminer
Can anyone tell me how much HP gain I will get from changing over to headers and a more efficient muffler? I'm currently getting 320 hp. My '81 930 is stock standard except for a 1 bar spring and I'm not planning on upgrading the turbo at the moment. I need to justify this project to myself before I tackle my wife!
03-08-2006, 12:15 AM
#24
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Flat merge collector is not as good as a triangular design. You don't see a flat merge on a set of Bow tie headers or on a 351W etc. Triangular merge is a more efficient design creating more velocity. That is exactly what the turbo wants to see.
As far as a diamond ring. I tell the kids in Karate class...you got to get some to give some all is fair in the mod game. Get what you can how you can. A ring is a small price to pay.
Dave’s car does that at the crank. We built and tested it here.
As far as a diamond ring. I tell the kids in Karate class...you got to get some to give some
all is fair in the mod game. Get what you can how you can. A ring is a small price to pay. Dave’s car does that at the crank. We built and tested it here.
03-08-2006, 07:07 AM
#25
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Originally Posted by 87turbo911
Wow...422hp? Wheels or crank?
I've got an 87 930 with Kokeln IC, K27, 964 cams, GHL headers and exhaust, Evo intake, no cat, and 1-bar spring. I'm short the fuel head mod and boost control. Any guess what I can hope for at the dyno? I haven't done one yet.
My butt-dyno says that there's a LOT more power from stock but butt-dynos aren't very accurate.
I've got an 87 930 with Kokeln IC, K27, 964 cams, GHL headers and exhaust, Evo intake, no cat, and 1-bar spring. I'm short the fuel head mod and boost control. Any guess what I can hope for at the dyno? I haven't done one yet.
My butt-dyno says that there's a LOT more power from stock but butt-dynos aren't very accurate.
03-08-2006, 10:44 AM
#26
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Cams can make a good HP difference, but more importantly they help lower the powerband and off boost throttle response. We all get caught in the HP game, but a car that has a broader HP/TQ band that makes 30 less HP is faster than one with a shorter one that makes 30HP more.
It will also depend on the cam but 20-25HP is a realistic gain from cams.
It will also depend on the cam but 20-25HP is a realistic gain from cams.
03-08-2006, 01:52 PM
#30
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87turbo911 -- I'd watch those AFR's at the dyno. ...you're going to start to go lean a little at 1bar (that is if you keep that all the way to redline), with no add'l fuel mods. Make sure you monitor boost also during dyno. With what you've listed (assuming you can get enough fuel), 400 rwhp is doable.
Stephen -- You've done enought of these things and I'm sure you've compared actual engine to drive train dyno. ...is drivetrain loss closer to 15 or 20%. Above mentioned divide by 0.85 being 17.6%
Stephen -- You've done enought of these things and I'm sure you've compared actual engine to drive train dyno. ...is drivetrain loss closer to 15 or 20%. Above mentioned divide by 0.85 being 17.6%