Power lost from fast intake swap??
Power lost from fast intake swap?? 
I took my car to a dyno day the other day and they did two pulls and the car put down 313 and 323 on the cut out , the last time it was tuned it put down 380. All I changed was I put a fast 92 intake and 92 throttle body on the car , it previously had a stock ls1 intake and tb.
It was a different dyno but both were dyno jets how does my car lose 60 hp and almost 100 tq from putting a much better intake set up on it .
Last edited by bguns10; May 1, 2017 at 10:04 PM.
something is really weird there. your torque peak rpm dropped from 4800 to 3500, but you never actually hit your peak HP RPM even out to 7000. your torque curve went completely flat and was still flat out to 7000 rpm. Especially the "lower" curve that looks like it was going to peak at 7500 rpm.
If I was looking at these dyno charts outside of this thread, I'd have thought they were two completely different engines.
If I was looking at these dyno charts outside of this thread, I'd have thought they were two completely different engines.
What kind of car, what kind of trans, what other mods?
Either the dyno runs are flukes or there could be a mechanical problem related to the install. Could be huge vacuum leaks, problems with knock sensors, big time MAF calibration issues, etc.
Has the car been tuned for the intake switch?
Needless to say I would hope you could feel a loss of 60hp and 100 ft/lbs so my money is on improper dyno runs either due to equipment issues or operator error. Kind of appears your new graph peaks at 7000 rpm after a weird curve...I'd consider the runs to be pure bad data honestly. Almost looks like they did the pulls in 2nd gear instead of 4th.
Either the dyno runs are flukes or there could be a mechanical problem related to the install. Could be huge vacuum leaks, problems with knock sensors, big time MAF calibration issues, etc.
Has the car been tuned for the intake switch?
Needless to say I would hope you could feel a loss of 60hp and 100 ft/lbs so my money is on improper dyno runs either due to equipment issues or operator error. Kind of appears your new graph peaks at 7000 rpm after a weird curve...I'd consider the runs to be pure bad data honestly. Almost looks like they did the pulls in 2nd gear instead of 4th.
Ls1 honed to 3.905 blueprinted , diamond forged pistons , 7cc valve relieved, eagle h beams, ported and blueprinted ls6 oil pump, adjustable timing chain, slp under drive pulley, 98 heads that are ported 2.02&1.60 valves, o-ringed , dual springs, rocker trunion upgrade, custom length hardened pushrods, Thunder racing tr 230 reverse split cam 598 lift speed inc headers and hooker exhaust , fast 92 intake and throttle body , Delphi 85 mm mass air flow sensor and fast toys lid 98mm . Car has a t-56 and a moser 12 bolt with 4.10 gears , also has a walbaro 340 in tank fuel pump , heads and block are studded and it has stock injectors . I haven't got it tuned since putting the fast 92/92 on it
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any chance your throwing a code? fyi after my engine work my car drove in basically limp mode due to a tiny wire off the back of the intake manifold to the computer was broken. i'd get a new tune asap.
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I would take it to another dyno since that one is pretty f'd up.
Or even the same one as the first graph if you want to do an A to B comparison. But I have a feeling the previous owner provided that dyno sheet and you may be pretty far away from that dyno? If so, it may not be feasible to do that.
So without access to the previous dyno or a baseline run on a new dyno before the intake swap, you won't know how much you picked up or lost. Too many variables. Instead, you can get a new baseline for any future mods and dynotune the car for the changes the FAST provided to your fueling.
Or even the same one as the first graph if you want to do an A to B comparison. But I have a feeling the previous owner provided that dyno sheet and you may be pretty far away from that dyno? If so, it may not be feasible to do that.
So without access to the previous dyno or a baseline run on a new dyno before the intake swap, you won't know how much you picked up or lost. Too many variables. Instead, you can get a new baseline for any future mods and dynotune the car for the changes the FAST provided to your fueling.
Was the 85mm MAF in place before the intake swap?
The tune will need adjustments over a ls1 intake setup in general but if the MAF was changed you probably aren't even in the same ballpark anymore.
Still doesn't explain the graphs though. Something there was almost certainly wrong. Could have been the RPM feed, wrong gear, or something else but that dyno graph has little to no chance of being remotely accurate.
The tune will need adjustments over a ls1 intake setup in general but if the MAF was changed you probably aren't even in the same ballpark anymore.
Still doesn't explain the graphs though. Something there was almost certainly wrong. Could have been the RPM feed, wrong gear, or something else but that dyno graph has little to no chance of being remotely accurate.
No.
I'm gonna step out on a limb and say that you did NOT lose nearly 60hp & 100tq at the wheels.....without noticing it.....due to an intake swap or for any other reason.
Looking at your second dyno (the one with the low numbers), it looks like a 'bad read' by the dyno. Both the hp and the tq curve are just looks too linear.
If you can't take the car back to the first dyno, then compare track time.....if you race the car.
Of course......this is just my humble opinion.
KW
I'm gonna step out on a limb and say that you did NOT lose nearly 60hp & 100tq at the wheels.....without noticing it.....due to an intake swap or for any other reason.
Looking at your second dyno (the one with the low numbers), it looks like a 'bad read' by the dyno. Both the hp and the tq curve are just looks too linear.
If you can't take the car back to the first dyno, then compare track time.....if you race the car.
Of course......this is just my humble opinion.
KW