Headers and SRT on 99 SC400
11-09-05, 06:35 AM
#1
Lexus Champion
Thread Starter
Headers and SRT on 99 SC400
Posting for member SRQ400. Greg just installed the S&S Headers along with dual 2.25" pipes back to his stock mufflers. There was an unexpected problem in that the 1999-2000 SC400 exhaust manifolds are completely different than the GS400 manifolds that the headers were designed on. This means that these cars must have at least a Y pipe custom made.
The good news is that they were much easier to install than the GS400 and due to the single log manifold design and the more restrictive exhaust the power increase seems to be substantially better than the impressive gains that the GS400s are getting.
No dyno numbers on this car nor are they planned. Greg is a conservative guy about performance gains. With his SRT intake install he told me it was a bit softer in the low RPMs and stronger in the high RPMs. With the header installed his response was MUCH MORE enthusiastic and he reports significant improvement from low to high RPMs. He doesn't want to guess at the power increase but did say the car is MUCH faster and much more responsive.
He doesn't have good pictures of the header install or exhaust as both were done at shops in his absence. He did send me the following pictures showing his very nicely done customer SRT intake and ECU mod and you can see the headers in a couple shots if you look closely.
The good news is that they were much easier to install than the GS400 and due to the single log manifold design and the more restrictive exhaust the power increase seems to be substantially better than the impressive gains that the GS400s are getting.
No dyno numbers on this car nor are they planned. Greg is a conservative guy about performance gains. With his SRT intake install he told me it was a bit softer in the low RPMs and stronger in the high RPMs. With the header installed his response was MUCH MORE enthusiastic and he reports significant improvement from low to high RPMs. He doesn't want to guess at the power increase but did say the car is MUCH faster and much more responsive.
He doesn't have good pictures of the header install or exhaust as both were done at shops in his absence. He did send me the following pictures showing his very nicely done customer SRT intake and ECU mod and you can see the headers in a couple shots if you look closely.
11-10-05, 03:57 PM
#2
Lead Lap
Ok... I'm raising my eyebrow,... cuz I got the mod bug,.. how much $$$???
JBrady,.. who around here do you think can correctly install an SAFC II ???? and properly dyno tune?
JBrady,.. who around here do you think can correctly install an SAFC II ???? and properly dyno tune?
11-10-05, 04:02 PM
#3
Forum Administrator
iTrader: (2)
JBrady,
SRQ400 made a post about it himself and has some pics in the link in this thread
https://www.clublexus.com/forums/sho...d.php?t=186633
Nazty, check the FAQ sticky in the GS forum here
https://www.clublexus.com/forums/sho...d.php?t=180708
SRQ400 made a post about it himself and has some pics in the link in this thread
https://www.clublexus.com/forums/sho...d.php?t=186633
Nazty, check the FAQ sticky in the GS forum here
https://www.clublexus.com/forums/sho...d.php?t=180708
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