I just did the trans and motor mounts on my 99 SC400.
My car has 62,000 miles and the difference was also huge!
My headers should ship later this week. Paul at PPE assured me they have solved the QC problems and the headers will be closely inspected.
I had my car dynoed on Monday so I have a baseline and I will post the dyno results after the headers and new y pipe ( John Brady design)
are installed.
https://www.clublexus.com/forums/per...vvti-dyno.html

 

Just noticed that your dyno (your link above) showing 255hp and ~295tq states at the flywheel. This would make sense. You are probably at around 210whp and 245wtq currently as a baseline dyno. This is suggesting a 17% loss from the drivetrain. New, the car came with 290hp and 300tq. So, you could be down a little bit on power due to the car being almost 12 years old (i.e. loss of compression). With addition of these headers you should see a nice increase. Make sure you clean that throttle body, change air filter and change spark plugs; this will help ensure you are running efficiently.

 

The dyno actually shows about 290hp. The left side scale is for bhp while the right side is for torque.

 

The dyno used was a Dyno Dynamics.
Known as the heartbreaker dyno because it typically reads 17% lower then
a Dyno Jet. The Dyno Dynamics used was recently calibrated and is using the latest software. This new software calculates Dyno Jet ratings because most tests are done on the more readily available Dyno Jet. For legal reasons they can't put rated Dyno Jet power, they call it flywheel. The 255.8 hp and 290lbs torque is at the rear wheels. The compression on my motor is bang on spec and
runs strong. The car has 62,000 miles on it. Here is a link to the shop that did my car. It shows some of the other cars that have been dynoed and with talking to the other cars owners the numbers appear to be accurate.
http://5252motorsports.com/

 

^ not to turn this thread into something other than the PPE Header talk but if your car was rated (when new) at 300tq how are you at 290WTQ without any MAJOR mods. From your previous post you don't even have your headers installed yet!? and...I know about the Dyno Dynamics dyno's as my car was dyno'd on an AWD one at No Limit Motorsports here on L.I. (NY). However, MY dyno sheets do not mention flywheel power anywhere. FYI...my baseline runs were IIRC around 245whp and I think around 267wtq and that's when I just had an intake and exhaust. Very much in-line with the stock rated 300hp / 315tq that the GS400's put out when new. If you just have an intake and exhaust your numbers definitely seem high especially for an SC400 which makes a little less power than a GS400...stock vs stock.

Who knows, if your dyno is at the wheels and is accurate you may be the very first SC400 to break 300whp with the addition of headers, A/F controller and some other bolt-ons. I have yet to see an SC400, SC430, GS400 or GS430 achieve this. The ones that do (without being FI) have nitrous or Meth setups. In any event congrats on a great running Lex!

 

I agree, the numbers seem high. I called them today to confirm the information I mentioned above. The main thing for me is to have a baseline. It will be interesting to see what the numbers are after the headers are installed.

 

$300 for the tranny/engine mounts labor. Did it with timing belt/water pump for $800 total. Parts from Sewell of course.

 

not to bad a price....actually way cheaper than i would have thought. wonder if it was so cheap since they already were in their?

 

Hey guys I had a question. I am in the process of putting my engine back in my car and was wondering if you guys were able to use the same stock gasket from header to cats? I know headers don't have recessed seat for old gasket to sit into. Or if you did reuse how did you get the gaskets to stay in place? Thanks in advance.

 

While you MAY get away with re-using it is better to replace both O-ring type gaskets on both the cat inlet and cat outlet. Cost around $10/ea. If yours leak it can cause an O2 fault code.

 

My fault , I definetly plan on installing new gaskets. I've spent a lot already on engine overhaul i'm definetly not going to skimp on some $10 exhaust gaskets now. My question is on the new PPE header, they do not come with the original exhaust manifold recessed cut out for gasket to sit into. So I was wondering if the original gaskets "new" would still work? Or did anyone come accross any replacement gaskets?

 

I used new oem with a little silicone to tac it and hold em in place the key is to tighten bolts with a even pattern dnt crank one down and then the other find a pattern and gradually crank em down

 

Yes, this was also the situation on the S&S flanges that did not have the recess and worked with good reliability.

 

Thanks for your help guys.

 

I used new gaskets without silicone though. I'm now getting a code for a leak on the other side (before was passenger). The leak is not that bad though because it takes a long time before the CEL comes on. 95% of the time, the O2 sensor (bank 1 sensor 2) is reading like it should. I really wished they made a recessed seat. Would have made things a lot easier, and it's not even that hard to mill out.