Rrecently I nstalled a new clutch in my car when the stock unit gave up. I replaced it with the McLeod RXT and it feels great. Ever since the car has been back up and running it is down on power for sure.... it is still fast but lacks much of the performance down low and up top as well. the car has a ported trinity tvs with a 2.4 pulley and 10% lower and will no longer spin the tires in second gear on my street tires like it used to. I have checked the usual stuff like fuel filter, changed the plugs, checked the bypass valve, put a new air filter on it and checked for vaccum leakes. It still seems to be making boost and I don't really think the belt it slipping at all. At this point I don't know what to do next..... I don't have any CEL'S to steer me in the right direction. I'm sure the next thing to do would be to log it or put it on the Dyno to see if they can see something I can not. Anybody had a similar problem? Im at a loss.... thanks for the help
Down on power
- Thread starter devilish64
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When you hit the gas and accelerate, do you notice any engine rpm flares/slipping clutch? A clutch change shouldnt hurt your power at all.
No check engine lights? No exhaust leaks? All sensors plugged back in?
No check engine lights? No exhaust leaks? All sensors plugged back in?
One guy melted his O2 sensor harness on a H pipe install. Did you scan the car for codes vs. just relying on the CHECK ENGINE light?
I am guessing you got an upgraded heat exchanger? It's still pretty hot out so it could be heat soak?
Yea I have an afco dual fan heat exchanger and a aeroforce gauge to monitor IAT'S.... I have no codes at all. The car has really good driveability.... makes all the same noises it did before the clutch except for more popping in the exhaust than I remember. It just feels like I've lost 100+rwhp ..... I have been over 700rwhp for a long time now and I know when it should spin the tires and when it should hook. Right now the car won't spin barely at all with 20" all season tires in second gear where before it would have blown them off in third. I really don't think there is any problem with the clutch install although it is odd that it happend directly after it. I was researching if bad O2 sensors would cause something similar but I'm almost sure I would get some kind of code for that. Thanks for helping gentleman!!
Have you taken the car to the track ? You could run it and see for sure.
You mention that you could spin the tires before but not now. Could it be that before the clutch was slipping and you thought the tires were spinning and now that it does not slip it feels different?
Sounds like heat soak to me. Put water in the ic reservoir.
What degree are your iats at?
What degree are your iats at?
IAT'S are Never over 130 unless it's 90 degrees out..... it is definitely not heat soak..... and unless the clutch has been slipping the entire 5 years I've had the car.... I don't think that as is the problem. The car used to spin at will in the first two gears and would spin in third as well depending on tire. It would hook OK on dedicated drag tires but it is making over 750rwhp on E85..... that is to be expected in my opinion. Maybe I will have to put it on a Dyno and see for sure if my suspicions are correct. I have had a vaccum leak on the inlet of the supercharger once before and it did feel to be down on power and have a lag in acceleration like it does now..... but I have been unable to find anything leaking. If feel like on the hit of the throttle it sort of falls on its face.... and then picks back up and starts moving..... but it lacks the PUNCH theese cars have at the hit of the throttle
do some data logs and check the timing to see if it's being pulled. could be something simple like vibrations making the knock sensors pull timing.
my buddy put LT's on and a stud came loose. that small thing tripped the knock sensors to pull timing up top. it just fell off at 4,800 rpm.
I'd get underneath and go through everything you touched to ensure nothing was forgotten or left loose.
Mike
my buddy put LT's on and a stud came loose. that small thing tripped the knock sensors to pull timing up top. it just fell off at 4,800 rpm.
I'd get underneath and go through everything you touched to ensure nothing was forgotten or left loose.
Mike
could be your intercooler pump going out too. I would datalog the iat2 temps just to see what that is doing first. Actually go ride for a lil while and see if they climb up high. quick and easy to do.
If its not doing that then it sounds like it is pulling timing for some reason. I recently went through a similar situation. Changed my PCV and O2 sensors, and my tuner had to build a new tune ( almost like the original tune was corrupted ) from scratch for some reason cause it was still pulling timing like crazy. After that it was all good.
I'd check to be sure you didn't pinch an 02 harness between the block and bellhousing when you did the install. I've heard of that happening a few times.
OP, sorry to bother you again, but "Did you SCAN the car for codes, or are you just relying on the check engine light?"
I have a 2007 so no knock sensors.... the O2 sensor harness being pinched hadn't even acrossed my mind. I did a little research into the subject and most people that had that happen got CEL's for the O2 sensors wich I do not have. I'm still gonna jack it up and check to make sure I didn't **** up. Has anybody ever heard of possibly plugging the O2 sensors in on the wrong side? Either way I will jack it up and check for things that don't look right.
No it was one of my first mods..... why do you say that? I use that and my sct tuner to check and reset CEL'S
OP, I know you can monitor timing, but did you also install a wideband sensor with your AeroForce so you can monitor AFR? If you can record both of those during a WOT pull, they may tell you something.
This is starting to frustrate me.... even my girlfriend tells me my car feels slow at the hit of the throttle. Put a mechanical boost gauge on it today and it makes 21 psi and it doesn't drop off. I jacked the car up and went under with a flashlight to check for pinched wires and found nothing..... the way I see it I only have two things left to do.... put it on a Dyno and check everything and do a compression test on it. I still can't find anything wrong with it.... Input?
I'd pull the plugs. They will tell you a lot. On a previous '04 Cobra, I had very similar power loss and I had a crack in one of my plugs and somehow it was not firing consistently. The plugs will also show you if you are rich/lean and possibly detonating.
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My 12 did the same thing after the rxt and magnum xl install. lund tune cleared 99 percent of my problems, I think its your clutch protection that cant be turned off all the way. A tuner can take it down quite a few notches though.
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