My car has been a beast since day 1, and better with each mod, but lately, it feels really sluggish. I actually couldn't run down a Lexus IS350 over a 300 yard stretch.

I've got a slew of common and pretty safe mods, including:
-EVOMS CAI
-AH Pipes
-Custom ECU Flash
-LWFW
-Stage2 race clutch

Has anyone experienced a sudden change in performance? I am thinking I should have my ECU re-flashed by Softronic, GIAC, or REVO. My custom flash was very aggressive, and I've no issues with it over 20k miles with it. Gas is always 93 octane.

Help!
CATTMAN

 

Are you sure it wasn't an ISF?

 

Could it be that you are getting used to the car/power(hence GO-FAST-CRACK-PIPE addiction).....?

Find it hard to believe that the car would fall on it's face like that,especially without sending a 'code'.....but I am just guessing!

Stacy

 

What is an ISF? If that's a cranked up IS, it wasn't. And frankly, even if it were, it should be no match for a 997S as stock, let alone a modded one.

Stacy, there was definitely a change. Off the line, my head is no longer tossed to the back of my headrest. Feels like less air is going through the engine. Checked all my connections, and everything is as it should be. Only recent change was AH pipes, which can't be the cause- the issue is earlier in the system.
CATTMAN

 

bad gas?

 

Yeah, the ISF is a 5.0 L V8 with 416 HP and almost 400 TQ. Maybe it's time for a dyno

 

Nope, it was not an ISF. Owned by a colleague of mine.
Gas has been consistent. A dyno can't tell me what I feel, and I've lost something. But it can tell if something is way off, I suppose.
CATTMAN

 

Hmmm... Is it felt in the lower end like loss of torque? Maybe from your pipes?
Or maybe your spark plugs?
That happened to my old 944 and I found out it was my spark plugs~
And once in a integra that I had and found out it was the new exhaust system that I had installed making it lose alot of back pressure~
I would suggest taking it into the shop and having it checked out because the Dyno shows numbers and figures but at times the Dyno will not pick up the "feeling" that you might be getting~

 

Yes, it's primarily a loss of low end TQ. It's pathetic.
Off the line, I've got almost nothing. This has been a sudden change.

 

Like I posted above....if it is THAT bad wouldn't a code be thrown.?



I hope you figure it out,but please keep us posted when you do!!
Once you figure it out.......
If you do need more power I MAY know of a supercharger for sale......and NOT mine,LOL!!!!

Stacy

 

If you noticed this after the installation of the AH pipes, then I would suspect that you're losing quite a bit of backpressure. I suppose this explained why you felt a lackluster performance off the line. How about top end? Any difference? Did you feel a "kick" at any particular RPM?

 

20K miles /modded car-- Might be spark plugs . No need to reflash but I do feel it ought to be examined carefully again fir fitment issues too.

IS 350 is not a slow car . Maybe he got the jump off the line. If rolling momentum can be the difference too.

Perhaps you were so confident that you would win . Like Rocky 3 --your car lost the "eye of the tiger" and the Lexus was hungry like Mr T .

 

I would be seriously surprised if it's related to changing pipes, especially ones that are well designed and have proper testing behind them. Bypass pipes would give a loss in low-end TQ but that is equal to not running any mufflers at all, but that is a completely different topic. I would think (if at all anything is wrong) it might be related to engine management / electrical / fuel / intake (possible air leak?). It could be a variety of things, but it is usually one of those. Is car running smooth or are you getting some roughness on idle / rev?

Cattman, if you really feel something is not right can you get your car in for a dyno somewhere? That would really be helpful at seeing if something in the power curve is now not quite right, if car is running lean / rich, etc. I always dyno my car after making engine / intake / exhaust related changes. It's a good $60 spent for piece of mind and documenting what works and what doesn't. Wondering too if you can talk to the folks that did the orginal custom ECU tuning and ask them if any new mods might impact performance?

Thinking further.. Could also be bad gas! I had this happen about 6 months ago, filled up with 91 at an Arco and car ran like complete crap on power. I thought I had bad plugs or something, but another member here suggested it might actually be bad gas- they were right. Problem went away on next fill-up. I chalked it up to some knucklehead fuel truck driver putting 89 in the 91 tank.

 

Catt,
I know what the problem is. Stacy was havin the same thing. Sluggish, no torque............Can u say SC

 

Hey Cat, question could it be the LWFW? Just thinking out loud but wouldn't a LWFW decrease your torque off the line as the rotational mass is less therefore decrease your torque? I really don't know anything about that mod but when I was rebuilding my 1973 FJ40 landcruiser the FW looked like it came off a D90 bulldozer and that was so it would have a huge amount of torque for rock crawling I would think. Again, a bit out of my knowledge base but thought I would throw that out.