Rock-a-Lex

iTrader: (4)

I have a 2000 Lexus GS400 and have a K&N FIPK with custom CAI extension (wheelwell), Borla exhaust and TM spark plugs.

I know that MANY of you have this setup already: Intake, exhaust, 3.76 LSD and PI Torque Converter. I just want an idea of what these mods are capable of before I do something stupid like sell my car for newer technology - perhaps approx. 0-60 or 1/4 mi. times. I know these times will probably be estimates so if you would mind by giving examples of say...taking out a new mustang or WRX - this would help a lot!!!!! I understand that the 3.76 LSD and PI TC would cost around $2500 with installation; I just want to know if it is worth it or not. Thanks guys.....

Nick

Rock-a-Lex

iTrader: (4)

Sorry guys... I just searched; very extensive. However, if you could add anything if you have BOTH of these mods it would be helpfull. Maybe inidcate cons to (if there are any!) LOL.

BoostAddct

I am pretty much in the same boat as you, but I know the route I am going with things. I currently have the SRT intake and HKS exhaust. I have not installed my S&S headers yet, but I will be installing the Tq converter and Supra LSD. I will keep my stock gearing for two reasons:1) the 3.76 gearing drops your mpg by at least 2 mpg from what I have read. 2) if you plan on supercharging, turbo, or nitrous, the 3.76 gearing is too short and the tranny has trouble with shifting into 2nd and 3rd without hitting the limiter for some people. Since I will be adding nitrous I don't want to run into that issue so I will retain my stock gearing. BA GS400 I believe has stock gearing and is in the 13s all motor. Good luck with whatever route you decide to take.

Rock-a-Lex

iTrader: (4)

Thanks for the response bro. I feel like a lot of the newer cars like the G35 are able to hang with our V8 cars because they have higher gearing (3.73 I believe) where we have 3.23 gearing - stock. I guess Lexus had to keep it at 3.23 for our cars because they are only 5-speed autos whereas the G35 and such are 6-speed (so they can afford to have higher gears and still have great top-end speed). Our top end comes down if we throw in the 3.76 LSD...but not sure by how much. GS4xx tops out at 146mph electronically limited, with the 3.76 LSD _______mph? BTW, sounds like your going to have one bad GS on your hands after all those mods. Let me know how everything goes.

Nick

BoostAddct

I believe top speed will drop to around 140-ish from what some people have calculated. Don't take that as a guarantee, but that is what I have read also. There are a few variables though, mainly tire size which will also affect gearing and top speed.

Rock-a-Lex

iTrader: (4)

I have 19" Ace Trend (platinum finish - deep dish) w/245/35/19 Toyo Proxes T-1. Overall wheel and tire diameter is the same as my stock 16" wheel setup. I don't think I will be effected by the larger wheel size. Hey if the 3.76 LSD will drop the top speed down to 140 from 146mph. I can live with that! LOL. I don't drive that fast anyway. If you were me with just an intake and exhaust would you do the gears or a TC...or Both??? Thanks for all your help. Oh, BTW I'm having an S-afc contoller installed shortly so I can maximize my efficiency/performance of my custom CAI intake (do you think this will help???) Thanks again.

BA_GS400

iTrader: (1)

Welcome Rock-a-Lex.

With the torque converter and the gearing, your Lex can hang with and possibly beat a lot of those G35's, even the 350Z possibly. I've been able to give a good run to some WRX's or the Lancer's *IF* it's from a 20mph or above roll-on. I have a friend with each and their 4wd from the dead stop can easily beat you if they know how to drive it.

Your Lex can possibly run 14.0 - 14.1's without the 3.76 gearing. I only dipped into a 13.98 - 13.99 with the gears. Not as much of a gain as you would have thought by those gears but the car is a HELL of a lot more fun to drive now.

PS. those rims and tires you have may have the same diameter, but, they are heavier than the stockers probably and that will easily take a tenth or two off our your quarter-mile times.

oh yeah, there are several G-tech verified 0-60mph runs in the 5.2 - 5.7 range but I can't recall if they had the 3.76 gears, the Torque Converter or both. Sorry.

BoostAddct

The SAFC will definitely help as long as you have it professionally dyno tuned. That way it will be tuned for your specific setup and will maximize all of the parts you already have. The top speed with the 3.23 gears is above 150mph though so you will lose more than just 6mph up top. In my opinion the 3.73 gears are best for cars without any type of forced induction that don't mind the small drop in fuel mileage. For any forced induction setups I would stay with the stock gearing due to some people having problems with the tranny shifting even after vb upgrades. Again that is just my opinion, hopefully it helps you figure out which route you want to go.

Rock-a-Lex

iTrader: (4)

BAGS400,

Thanks a lot for your response... I really appreciate it. I also have (2) 12" subs in a box to slow me down. I'm just trying to achieve a little more power (or lost power from the weight of my wheels & stereo ) on my GS. That's great to know that the GS is capable of squeezing into the 13s in the quarter with N/A bolt-on mods. I am NOT just talking here... I need to do something soon to my car. I understand that speed and power isn't eveything but the GS4xx should still remain competitive; especially against the newer cars/technology (I don't want to sell her). I either want to buy the PI TC AND Torsen style 3.76 LSD OR a supercharger (turbocharger is just way too expensive for me). Which would you do... and where can I find a supercharger???

After pricing the PI TC ($750), Tranny cooler ($100) and the 3.76 LSD ($1,599) there would be a total of approx. $2700 w/shipping and add another $800 for istall of both?? and you arrive at a grand total price of $3,500. A supercharger would probably cost around $5500 and $700 +/- for the install. Now, I know where talking about almost $3000 more but will the car be THAT much more fast as opposed to the PI TC and the LSD setup. Which option would you suggest better bang for the buck overall?? (Or most happy with results)

Boost,

Thanks for the advise as well. I am having an import tuning shop (the ONLY one within 50 miles from me) purchase, install and dyno tune (3 pulls; Baseline + 2 tuning runs ???) the SAFC for around $600. I understand the broblem running the 3.76 gears with the FI in which you explained below...that's why I NEED to know which direction I should go in without having to uninstall a new mod later on (i.e the 3.76 lsd if I go FI).

Thanks for all the advise guys. I'm coming from LOC forums (they are great as well but seems like there are more maint. and light modding discussions). Probably hang here for a while. Thanks again!

BoostAddct

Supercharging is a great option, but definitely a little costly. Use the search feature and read about some of the members that have supercharged theirs. You will be looking at 320-400whp with a supercharger as long as it is installed correctly and tuned correctly. The thing that has scared me away from suparcharging is that you hit a cieling and when you try to run smaller pulleys in order to get higher boost, members have run into slipping belts and reliability and tuning issues. If you plan to just pick up an RM supercharger and leave it how they designed it you should be fine and not have reliability issues. I was definitely having the same dilemna as you when I first got my GS, I didn't need for it to be a race car by any means, but I did want to be able to hold my own. Since the FI options seemed to sacrifice reliability and driveability I have decided to go the all motor route. I feel that with the intake, S&S headers, full exhaust, tq converter, lsd(stock gearing for me), minor port/polish work on tb,intake mani, and heads, and a set of performance cams(keep your eyes open on the forum for these, production by a very reputable manufacturer is in the works), and an engine management system may be able to get a GS up to about 350whp and then a little nitrous on top of that and 400whp should be attainable. Obviously the cams will be a big part of the equation though so hopefully production goes as planned. Again good luck with whatever route you go and definitely do a search for more info on the FI route. To my knowledge no one has ever really gone the all motor route using port/polish work and cams due to no cam options being available.

DaveGS4

iTrader: (2)

Rock,

If you take a short drive there is one for sale for $1,200 in Baltimore in our classifieds forum right now.

https://www.clublexus.com/forums/sho...d.php?t=256875

Rock-a-Lex

iTrader: (4)

Thanks for looking out! I just sent him further inquiries via PM.

Brennan401

BoostAddct,
I would be interested in the all engine Mods( Cams, Heads, Valves, Mani). If they need interest to move forward, please put my name on the list. That is where I want my GS to be. So, any and all info; I would like to kept in the loop. Thanks you made my day.

BoostAddct

Sounds good Brennan401! Not to hi-jack, but here is what my all-motor plans are; Performance cams, extrude hone intake mani and port match tb, port/polish heads, bore out the tb, and possibly the Greddy V-Manage if that works out. I'm hoping for about 360+hp at the wheels without spray and then a 50-100 shot on top of that. I'll start a thread once it starts going together.