New motor fallinf on face
Thread Starter
Teching In
Joined: Aug 2012
Posts: 8
Likes: 0
New motor fallinf on face stock block forged bottom end cam etc ls7 stock heads with springs twin turbo
car made 1027 rhp 942 tq , turbo were 65mm , motor strong to 6500 rpm.
My new RHS block mast heads and twin 67mm turbos again forged internals
car falls on face after 5300 rpm makes 996 at 5200 at 5300 starts to fall off all the way to 7000rpm , the differences between the 2 motors bigger turbos , better flowing heads {mast } comp cam to pull to 7000, high rpm hyd lifters (lunati) , have been told to many changes , all the changes were to make more power ! any direction on what to tackel first , or has any one seen this happen
car made 1027 rhp 942 tq , turbo were 65mm , motor strong to 6500 rpm.
My new RHS block mast heads and twin 67mm turbos again forged internals
car falls on face after 5300 rpm makes 996 at 5200 at 5300 starts to fall off all the way to 7000rpm , the differences between the 2 motors bigger turbos , better flowing heads {mast } comp cam to pull to 7000, high rpm hyd lifters (lunati) , have been told to many changes , all the changes were to make more power ! any direction on what to tackel first , or has any one seen this happen
9 Second Club
Joined: Nov 2003
Posts: 13,616
Likes: 185
From: Norn Iron
Surely whoever is tuning it has some input as to what's wrong ? After all, they have the car there in front of them ?
it could be many things, but they should have the feedback to diagnose the problem.
Could be as simple as spark, valve springs, boost issue, blocked exhaust, turbo problem, electrical problem, bad tuning, fuel supply problem....really, the list could go on for a long time.
it could be many things, but they should have the feedback to diagnose the problem.
Could be as simple as spark, valve springs, boost issue, blocked exhaust, turbo problem, electrical problem, bad tuning, fuel supply problem....really, the list could go on for a long time.
Does it go lean up top?
Did you change the fuel system?
What was compression on the previous motor?
What is the compression on this motor?
How much boost on the other motor vs this motor?
What size exhaust housing on the other motor vs this motor?
The list can go on an on as there are many variables. So start with those and maybe someone else will chime in as well
Did you change the fuel system?
What was compression on the previous motor?
What is the compression on this motor?
How much boost on the other motor vs this motor?
What size exhaust housing on the other motor vs this motor?
The list can go on an on as there are many variables. So start with those and maybe someone else will chime in as well
9 Second Club
Joined: Nov 2003
Posts: 13,616
Likes: 185
From: Norn Iron
Who's tuning it ? They will have more info on how it was running than anyone, so will be in the best position to diagnose.
Static numbers like 11.73 mean little though.
That could mean the AFR is that, it could mean you're mega rich but with missfires etc etc.
A good graph or datalog with lots of information would be helpful.
Static numbers like 11.73 mean little though.
That could mean the AFR is that, it could mean you're mega rich but with missfires etc etc.
A good graph or datalog with lots of information would be helpful.
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Thread Starter
Teching In
Joined: Aug 2012
Posts: 8
Likes: 0
dyno & spks rhs block 427 ,4.125 bore mast heads 305 cc 12 degree 6 bolt nitrited ls valve spring (dual), titanium race 2.25 / 1.600 Inconel race vv
dragon sla crank , callei rods, diamond pistons comp cam .50, 247-247
stock ls7 rockers with tronions ,
com turbos cremic bearings 67mm .
motor dyno N/A 640 @ 6800 rpm
Car was at dyno 3 pull 2@ 14psi, 3rd @ 18 on controller log shows 17 psi ,with only 50 hp gain ... sounded great no indication of falling off in car , dyno graft
showed a huge steady drop in power after 5300 , could have slipped on drum ?I do not know , shop was turbos choking,to floating vv, wrong cam ,
fuel , etc .
have not attached file ,-
What do I need to do to attach file
dragon sla crank , callei rods, diamond pistons comp cam .50, 247-247
stock ls7 rockers with tronions ,
com turbos cremic bearings 67mm .
motor dyno N/A 640 @ 6800 rpm
Car was at dyno 3 pull 2@ 14psi, 3rd @ 18 on controller log shows 17 psi ,with only 50 hp gain ... sounded great no indication of falling off in car , dyno graft
showed a huge steady drop in power after 5300 , could have slipped on drum ?I do not know , shop was turbos choking,to floating vv, wrong cam ,
fuel , etc .
have not attached file ,-
What do I need to do to attach file
Could be intercooler Macedonia out. We had a tt viper lose 300 wheel up top. Tried everything only to realize the intercooler couldn't keep up. Built a new intercooler and eclipsed 4 digit numbers by a mile lol. Just food for thought
