My car sucks lol
08-10-2016, 09:37 AM
#1
My car sucks lol So i recently swapped my top end from factory 243 with GM MLS gasket (0.051) and an LS6 intake with stock TB/MAF and injectors (28#) over to PRC 225s w/ 0.040 Cometics, FAST 102, 102TB, 85mm MAF, and 36# injectors along with some Morel 5315s...I picked up a measly 36hp/24lb-ft and only changed my track time minuscule amount (12.33@110 vs 12.20@112) , pretty sad considering i put a BMR relocation trans cross memeber and torque arm on too...Cam is a Comp XR273 224/230 0.581/0.588 114
Not sure if maybe I put too much top end on a stock bottom end...also worth mentioning is that tuner had problems getting much timing (22-23) in it as he said knock sensors were tripping out...I still need to do a compression test just to make sure I have 8 good cylinders, but for the money invested I think I got boned big time $100/hp...should have just turboed the setup i had
Not sure if maybe I put too much top end on a stock bottom end...also worth mentioning is that tuner had problems getting much timing (22-23) in it as he said knock sensors were tripping out...I still need to do a compression test just to make sure I have 8 good cylinders, but for the money invested I think I got boned big time $100/hp...should have just turboed the setup i had
08-10-2016, 10:02 AM
#2
Those tracks times suck horribly both before and after.
If I had to guess: 1 5/8" longtubes, catted Y, and single 3". That is probably costing a good bit over a bigger set of headers and duals or at least a large ORY.
Car could also have a mechanical issue. Did you inspect the cam while the heads were off? Could have some damaged lobes, especially if you replaced the lifters due to damage (your post doesn't say why you changed lifters). Did you recheck pushrod length?
If I had to guess: 1 5/8" longtubes, catted Y, and single 3". That is probably costing a good bit over a bigger set of headers and duals or at least a large ORY.
Car could also have a mechanical issue. Did you inspect the cam while the heads were off? Could have some damaged lobes, especially if you replaced the lifters due to damage (your post doesn't say why you changed lifters). Did you recheck pushrod length?
08-10-2016, 10:33 AM
#4
Agree completely thunder...
could be headers, they are Hedman 1 5/8" so def not top shelf, y-pipe is theirs as well with high flow bullet cats welded in
Cam was good, just replaced lifters because they were the original 80K mile ones
Pushrod length was checked and set to preload spec suggested for the Morels (0.050")...
Just trying to track down why there is such a lack of power... tuner said fuel wasn't the problem which was my first guess
could be headers, they are Hedman 1 5/8" so def not top shelf, y-pipe is theirs as well with high flow bullet cats welded in
Cam was good, just replaced lifters because they were the original 80K mile ones
Pushrod length was checked and set to preload spec suggested for the Morels (0.050")...
Just trying to track down why there is such a lack of power... tuner said fuel wasn't the problem which was my first guess
08-10-2016, 10:34 AM
#5
I am gonna pull the car in the garage and check plug and compression for sure...i only used blue lactate on rocker threads so I want to make sure oil isn't getting past them which could cause knock... any other suggestions for diagnostics?
08-10-2016, 10:54 AM
#6
Basics:
check for WOT at the blade, have someone look while you push the pedal to what you think is WOT...often carpet or floormats or stretched cables prevent true WOT, especially with a new intake setup
check plugs for cracks, inspect all the plug wires (a friend was diagnosing a misfire and asked me for help, sure enough he found a messed up wire after I suggested he check there first)
try to thoroughly look for vacuum leaks
compression test and leakdown, could be leaking past the rings
for the price it might not hurt to try some new knock sensors and a new harness on them...that could easily lead to poor performance with both setups....but also more importantly if you are buying **** gas from: Casey's, Kum N Go, Wal-Mart, Murphy's, EZ Mart or any other similar bargain chain stop and try to find a top tier fueling station with 91-93 octane, preferably non-ethanol.
Making sure you have quality fuel is the very first thing to do when you have or suspect KR.
check for WOT at the blade, have someone look while you push the pedal to what you think is WOT...often carpet or floormats or stretched cables prevent true WOT, especially with a new intake setup
check plugs for cracks, inspect all the plug wires (a friend was diagnosing a misfire and asked me for help, sure enough he found a messed up wire after I suggested he check there first)
try to thoroughly look for vacuum leaks
compression test and leakdown, could be leaking past the rings
for the price it might not hurt to try some new knock sensors and a new harness on them...that could easily lead to poor performance with both setups....but also more importantly if you are buying **** gas from: Casey's, Kum N Go, Wal-Mart, Murphy's, EZ Mart or any other similar bargain chain stop and try to find a top tier fueling station with 91-93 octane, preferably non-ethanol.
Making sure you have quality fuel is the very first thing to do when you have or suspect KR.
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08-10-2016, 12:13 PM
#8
....but also more importantly if you are buying **** gas from:
Casey's,
Kum N Go,
Wal-Mart,
Murphy's,
EZ Mart
......or any other similar bargain chain stop and try to find a top tier fueling station with 91-93 octane, preferably non-ethanol.
Making sure you have quality fuel is the very first thing to do when you have or suspect KR.
Casey's,
Kum N Go,
Wal-Mart,
Murphy's,
EZ Mart
......or any other similar bargain chain stop and try to find a top tier fueling station with 91-93 octane, preferably non-ethanol.
Making sure you have quality fuel is the very first thing to do when you have or suspect KR.
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08-10-2016, 12:56 PM
#9
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What size chamber PRC heads did you get? Have you checked pushrod length now that it has been ran? What AFR are you running above 3500 RPM? What plugs? Stock ECU?
The lack of timing has something to do with it. If you went with the 62cc heads and thinner head gaskets, your CR is a little high for that small of a cam.
The lack of timing has something to do with it. If you went with the 62cc heads and thinner head gaskets, your CR is a little high for that small of a cam.
08-10-2016, 01:17 PM
#10
Yea we used BP 93 to rule out the fuel related knock
correct 62cc chambers, ac iridum plugs...i don't have log files for AFR of dyno runs...may check pushrods again if everything else checks out
I have been looking at trying a different cam, i should have changed that while i was doing everything else but figured i would run what i had to see what i had first...not much haha
correct 62cc chambers, ac iridum plugs...i don't have log files for AFR of dyno runs...may check pushrods again if everything else checks out
I have been looking at trying a different cam, i should have changed that while i was doing everything else but figured i would run what i had to see what i had first...not much haha
08-10-2016, 11:04 PM
#12
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Agree with Thunderstruck on the 1 5/8" and small y choking the out put.
You have FAST 102 / 102 which could be argued Is larger then needed
With the rest of your set up, 1 7/8" with true duals probably 25 maybe
30 RWHP over what you have now.
You have FAST 102 / 102 which could be argued Is larger then needed
With the rest of your set up, 1 7/8" with true duals probably 25 maybe
30 RWHP over what you have now.
08-11-2016, 08:23 AM
#14
Y-pipe is 3" on both sides, but i remember the cats were an off brand that i got for cheap so who knows what they flow...they don't get super hot and smell so they are at least not clogged...i see people making some nice power with factory y pipe with flat section, but it is possible this is my restriction.
NAVY...i agree on the 102, but i got such a smoking deal on it that I couldn't pass it up...im was lookin into the texas speed headers/true dual setup so maybe ill try that out...not sure if i want to address that or the cam first, at minimum i should check and make sure the cam was installed straight up because i didn't degree it in when i installed in like 4 years ago
NAVY...i agree on the 102, but i got such a smoking deal on it that I couldn't pass it up...im was lookin into the texas speed headers/true dual setup so maybe ill try that out...not sure if i want to address that or the cam first, at minimum i should check and make sure the cam was installed straight up because i didn't degree it in when i installed in like 4 years ago
08-11-2016, 10:59 AM
#15
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bigger headers,better y and free flowing exhaust will help quite a bit but the low timing is a big problem imo. knock sensors could possiblt be picking up false knock. on the dyno it isn't under much load (just load of the drum ) so it prolly isn't actually spark knocking like it possibly would under heavy load on the street in a heavy vehicle. i would think with that setup you should be able to clear 430 rwhp,390- 400 rwtq so first thing i would do is try to figure out why it won't handle 26-28* timing like it should be able to.
maybe have the tuner desensitize the knock sensors or something.
maybe have the tuner desensitize the knock sensors or something.
08-11-2016, 12:51 PM
#17
My plan is to replace the knock sensors and either run open headers like Bud mentioned or just take Y-pipe off and take a look at cats and make sure they aren't clogged causing a restriction and then do some more dyno runs...all this in addition to the checks that i have mentioned before...appreciate the comments as this car got me pissed to say the least...
