SCV8

Those bigger pipes will definately help the torque figures a little, a great mod indeed I suppose, and it sounds like you pulled it off for a decent bargain, but without actually passing a probe thru the old stockers, you can't tell me that you have determined what something is by your trained ear alone.

rdm20fan

C.M. Racing builds a 3' dual for the SC

livesc400

I ran a metal clothes hanger through oe of the stock mufflers. My stock mufflers are definately not straight-thru. This may be different for 1992-97 SC's though.

CyberSC4

Well, after reading all this info about dual exhausts and such...and seeing/hearing LiveSC400's great vid. I woke up early this morning and took my car in for a little operation :-)

All piping was replaced from center resonator back with 2.25 mendrel pipes leading to stock mufflers....funny though; I'm in Cali and I don't have a 3rd cat. My stock pipes looked just like LiveSC400's.

Anyways...my impression is first, great sound. At idle and cruising speed it's quiet as stock. Punch it though, and the exhaust lets out a very unique tone. To me it sounds like a G35 on steroids. The extra 2 cylinders and the trademark burble make all the difference. Out on the road, G35's, Z's and Mustang owners all took notice.

Power-wise, there is definitely a change for the better. I'm running a cold-air pipe from the lower grill straight into the airbox...so those two together should amount to some decent power gains.

For a meatier sound...you can unclip the top of the airbox. Sounds great, but at the cost of sucking in hot air (if using a stock intake and snorkel). If you're running a cold air pipe from outside the car, unclipping the airbox lid actually help overall performance at WOT (according to Planet Soarer).

livesc400

WOW...now that's some good stuff. Good to hear everything turned out well Cyber. Let's hear that Toyota V8 Rumble . I actually replaced my rear mufflers with Dynomax Turbos and 3.5" oval tips. I will have pics and a vid soon. Good to see others trying some exhaust mods on our very restrictive stock exhausts.

BTW how did you run your cold air setup? Have any pics/instructions? I only have a Supra panel filter in the stock airbox. My snorkel is still there but I was planning to do the unclipping the cover mod.

CyberSC4

In order to route the cold air, I ran a dryer hose from the lower passenger duct up into the airbox.

1. open up the passenger side wheelwell and unscrew 2 bolts holding the headlight in place
2. from the engine bay, unscrew 1 bolt holding the headlight
3. (be sure all lightbulb connectors are undone)
4. slide the headlight out from the body
5. you'll now see the stock intake snorkel sitting under the headlight
6. remove one screw and the snorkel slides out
7. run 4" dryer hose from front duct and into the opening for the airbox
8. hose can be secured at the duct opening by using the factory screw for the passenger-side fog light (looking into the duct, you'll see a single screw. undo it, place the hose up against the side of the duct and reinstall the screw and washer from inside the hose.

It's easy as pie. I'll try to get pics

BiZ

Hi guys,

Sorry to bring this back from dead and I know this doesn't have a whole lot to do with the SC400, but here is some of my personal experiences with "air flow mods".

Exhaust is a great mod for a DOHC V-8. My previous car (1991 ZR-1 Corvette) and my current car (2004 Cobra) are both DOHC 32v V-8s. The ZR-1s LT5 engine is a 5.7L V-8. The Cobra has a 4.6 L V-8 and is very easy extract power from, thanks to a Eaton M112 supercharger on top from the factory.

The ZR-1 stock exhaust is a 2.5" non mandrel system. But it would neck down to about 2" where it connected to the resonator and the mufflers. I did dyno tests after each mod on the ZR-1 to see where and how much power was gained. I did a stock dyno pull and got 328rwhp and 333rwtq with 94k miles on the clock. The first mod I did was adding a set of 2" primary Stainless Steel long tube headers. The peak gains were pretty good but not for the cost incurred ($1100). The peak numbers were 345rwhp and 337rwtq. Under 4500RPM the gains were minimal if any gain at all. After that though the motor really made some power. The headers extended the powerband another 1000RPM. Above 6000 RPM the power increased from 300rwhp to over 330rwhp. The next mod was the installation of a cat back system. This made nice gains From 3000RPM to redline. The cat back "flattened" the powerband in the upper RPM band as shown in the graph below. With a full exhaust system the car picked up 30rwhp and 12rwtq peak. But after peak power the car picked up over 50rwhp. The next mod was to have the intake ported out. This consisted of porting the injector housings and the intake plenum. The gains were all after 5000RPM and near the 25rwhp. The car was a real animal up top. The last thing I did was have the car dyno tuned. The was by far the best bang for the buck. The car picked up over 20rwhp and 25rwtq. The final numbers for the car were 405rwhp and 378rwtq. All of this acheived with just exhaust, ported intake, and a dyno tune. Below Is a graph of each mod and the results.The only file I couldnt put in the comparison is the dyno tuned file:

blue---headers
red--- the above + flowmaster cat-back
green---the above + ported plenum/inj housings



Sorry for the long post. I just wanted to share a little of info that I have collected over the past couiple of years modding cars. I don't know how well the Lexus V-8 will respond to similar mods. But I would think, after seeing the stock exhaust, that a decent exhaust would really help the powerband.

livesc400

WOW! Tha'ts some good info. I did notice a significant increase in the power band from 2000rpm all the way to just before redline. Our stock exhaust is sooooo restrictive. All stock SC's must learn to breathe easier . I may try to get the car dynoed one day to see how much power I am putting out with my $15 BFI and exhaust mods. I did consistently beat a SRT-4 Neon with intake, BOV, and exhaust (friend of mine) but not by too much. He's quite a good driver and runs high 13's to low 14's in the 1/4 mile at the track. If I end up keeping my car, I am going to get a local shop to fab me up some headers and see what the ol' SC400 w/ 250k miles can do.

Thanks for the info!
LiveSC400

JTJerryls400

1 question :
2.25" it is INSIDE or OUTSIDE pipe diameter?

thanks
Jerry

BiZ

Exhaust pipe diameter is measured using the Outside Diameter.

SCV8

I always thought that OD thing was odd with the tubing sizing, since the business is all on the ID.
I have wondered what a ZR1 would do with a little help for some ten years now, not too many around.

BiZ

It is definitely one car I regret selling. And too think I would be receiving the title around this time if I wouldn't have sold it last year. It was a hoot to drive. The motor was a work of art. But boy was it expensive to modify past the level I had mine at. There is a company in Georgia making a twin turbo kit for the ZR-1. Here are a couple of pics of my ZR-1.





I really miss that car.

SWSC400

Just got mine done today and am lovin it Thanks livesc400 for this thread, I was just going to put on my magnaflow 14829's and leave everything else stock, but after seeing how you did things I decided to go ahead and install the magnaflow x-pipe as well! All 2.25" piping and had the hangers added to where the resonators used to be. I was worried it might be too loud, but it sounds great