Assuming under ideal conditions the IS350 does 0-60 in 5.3 seconds. After adding a Tanabe exhuast and a JoeZ intake would it be reasonable to assume that under those same ideal conditions that the IS350 could drop that to 5.0 seconds or better or is there not enough of a HP gain?

 

I would say there is not a gain of enough hp to drop that far. As you rcar is faster and faster it takes exponentially that much more power to drop times.

Ie. a 350 could drop .2 second to 60 with a gain in ~30 hp. To get another .2 second drop in time would take ~65hp.

Hope that makes sense. BTW these are in no way accurate.

 

I would assume it would take 30 or 40 hp gain to get that increase in performance.

 

So if the intake and exhaust don't really add much in terms of power converted to speed are they essentially cosmetic upgrades in line with redouts, aero kits, tint... etc.? The reason I ask is because I'm contemplating my next upgrade and I was going to go with the intake then exhaust, but if they don't really add much in terms of performance then I might go with an HID upgrade and new front lip. Anyone have any comments?

 

Intakes add near zero... the Joe Z pipe is a lot cheaper than any of the others offered and might gain you 3-5 hp on a good day, which is as much or more as the more expensive ones.

Axle-back exhausts (ie the legal ones) will give another 5-7 hp for something in the 550 buck and up range... illegal (deletes secondary cats) exhausts will be double that or more in price but add double that or so in hp (12-15)

The Mazzuri headers haven't been tested on an IS350 yet, and aren't even remotely street legal (delete primary cats) but they gains nearly 25 hp and 30+ torque on an IS250 so gains ought be as good or better on a 350, and they run around $750ish I think.

And that's pretty much it for mods to add hp. Weight reduction is your other (sometimes free) option.

Note at least one car mag got 4.9 0-60 out of an IS350 bone stock.

 

Ok, first of all you bought a lexus, if you want a 'sports car' you for sure dont walk into a lexus dealership right? AND you have a 350 already, stock were fast enough for street use, if you wanted something faster for the street... again, see the first sentance... now having said that...

JoeZ pipe, according to the dyno graphs you'll gain minimal top end power BUT it will improve on the midrange *as your getting to redline*, everyone seems to look at the redline number only and i dont know why , course the biggest improvement in the midrange (which is great for dailydriving) seemed to be on the 250 cars. Do i have one on my 350? no. Do i want one? i dunno i feel the 350 is fast enough for the street already...

Exhaust, its a axleback *its still behind the cats so i call it catback but whatever* and you'll still have the bottlenecks in the rest of the exhaust system anyways so... mostly for sound/looks only, tanabe is the most popular choice. Do i have one? no. Do i want one? I'm wating for my economics package check to buy it so yes.

imo? go the 'show' route first because the 'go' route is pretty much a placebo...

 

Get a Joe Z, and lighter rims and save up later for headers maybe. If you want noise without much if any gains get a Tanabe too. If you feel like scraping your bumper on driveways and wearing out the inner parts of your tires in 2 months then you can lower your car. That's about it thus far.

 

roadandtrack.com gets 5.1 for the is350 stock... it all depends...

 

^^ actually 4.9 if u look in any recent magazine from them

 

Here is the article with the R&T test numbers.....

http://www.roadandtrack.com/assets/d...car_dp.pdf.pdf

 

Thanks guys for all the responses. Since the intake and exhaust are more psychological performance upgrades I might get the HID and front lip upgrade first then go ahead and get the intake and exhaust later on. I actually like the quiteness (is that a word?) of the stock intake and exhaust. With the windows rolled up it sounds stealthy almost like an electric car I'm sure that'll eventually grow old and I'll want it to sound a lil meaner.

BTW llama, do you have any squeking or bushing type rubbing sounds coming from the rear becuase of your Prokit?

 

You have the right idea... reduction in weight would serve better to increase speed on ISX50s... AND you would need major HP upgrades (and $$$) to see significant 0-60 time reduction

 

Weight reduction (especially wheels) and grippy tires will do the most for improving 0-60 times.

 

You know...I wish these magazines would give us their launch techniques when they post these numbers.

The only exception is that Road & Track mentioned that used the "floor it and go" technique. I would assume that they had the car set to PWR, and perhaps turned off traction control.

 

no.. PWR slows you down!