Dyno comparison, two US 16V's with 3" straight exhaust
12-02-2011, 10:43 AM
#31
Rennlist Member
I wonder how much more power my 4.7LH would make with '85/86 manifolds and an X-pipe?
If adding 300cc to get 5.0 is good for 40HP then I would be very intererested in doing a hybrid.
If adding 300cc to get 5.0 is good for 40HP then I would be very intererested in doing a hybrid.
12-02-2011, 02:23 PM
#33
Rennlist Member
i suspect the headers i put on are not too much better than the 85 manifolds, just a little. but, i put them on with the exhaust and the gains were a solid 12hp for the headers and 12hp for the open exahust. dont in sucession and on the same dyno. 178 to 200rwhp for both. there are a few that got 220rwhp for the same mods, but as i said, my 4.7 was very weak after 150,000miles of hard driving, DEing, etc.
Mark
Mark
12-02-2011, 02:27 PM
#34
Rennlist Member
Hey guys
I have a bunch of dyno runs from my 79 with a euro 4.7 motor 10.4:1 compression. Really interesting to see the improvements from adding 86.5 exhaust manifolds, then adding 3" exhaust single pipe system. Highest I got was 260whp.
The 86.5 manifolds added 24rwhp above 5000rpm (peak increased by about half that but they really opened up the breathing at the top end). When we added the full 3" system peak hp increased by another 16rwhp or so.
I'll try and dig the charts out.
Joel
I have a bunch of dyno runs from my 79 with a euro 4.7 motor 10.4:1 compression. Really interesting to see the improvements from adding 86.5 exhaust manifolds, then adding 3" exhaust single pipe system. Highest I got was 260whp.
The 86.5 manifolds added 24rwhp above 5000rpm (peak increased by about half that but they really opened up the breathing at the top end). When we added the full 3" system peak hp increased by another 16rwhp or so.
I'll try and dig the charts out.
Joel
interesting you have 260rwhp. all our euros with euro mods (all the euro stuff on top, even cams, and heads made 250rwhp solid. so, you got about 10 more for the MAF i would guess which is what we all think that is worth.
adding just the 300ccs, we got 40 more hp to 290 hp. dont know why, but it was consitant with two builds.
12-02-2011, 02:34 PM
#35
Nordschleife Master
Mark,
its less about the CCs, more about the CR jump that you are achieving.
This isnt rocket science.
I managed to get 250rwhp on a mustang dyno out of a stock 84 engine.
It used 86 manifolds, 2.25" downpipes to a single 3" w/ a borla cat back, modified intake and EFI.
But Hacker, this doesnt make sense I mean we have all been told that the larger exhaust on the 16V looses torque....... You must be doing something wrong!
its less about the CCs, more about the CR jump that you are achieving.
This isnt rocket science.
I managed to get 250rwhp on a mustang dyno out of a stock 84 engine.
It used 86 manifolds, 2.25" downpipes to a single 3" w/ a borla cat back, modified intake and EFI.
But Hacker, this doesnt make sense I mean we have all been told that the larger exhaust on the 16V looses torque....... You must be doing something wrong!
12-02-2011, 08:08 PM
#36
Nordschleife Master
Gains from the y can be pretty nice, and I've wondered a lot about the 97.5 to 100mm 4.7 to 5.0L and if part of what we are seeing is shrouding of the intake valve on the smaller bore?
