daihap133

I recently brought a 99 GS400, 139000 miles on it, to my suprise, the power or acceleration is still VERY good!!! My first thought, since this is a high mileage vechicle and went through 10 years of service already, the power would have deterioated at least 30-40%, I am really suprise when I test drive it, the power is just as good as new!

Now, I want to put in one or perhaps a dual vortech sc setup, here are my questions:

1/. Since it already has 139000 miles on it, will it be able to take 7-10 pounds of boost without messing around with the engine like putting in a low compression piston? I don't want to brow up the engine.

2/. No one sells a SC kit for this car, I have search on the web, none.. SRT and rod millen has made a kit for it in the past, but I cannot find anyone sells them. So I will have to get a SC compressor and custom make all the other parts such as mounting bracket, idler pulley myself. To drive the SC, I have two choices:

A. I either get a crank pulley that has the same rib(#of ribs, pitch, angle) in the sc pulley, figure out a way and stack it on top of the crank pulley, and drive it with a serpetine belt.

B. or , get a longer belt and reroute the entire belt drive, a longer belt drives everything ,the ac compressor, steering pump, alteranator,idler pulley, the SC unit, but then I have find a pulley that match the rib(#of ribs, pitch, angle) in the origninal GS400 belt drive system.

Either way will be difficult because the pulley in the Vortech SC may be different than the pulley that the GS is using(in terms of the serpentine pitch, angle, and #of ribs in the pulley).

HOW would you solve this problem?



3/. Fuel managment wise, I would need a larger flow fuel pump and larger size injectors, what CFM rate fuel pump would I use? Is there is a fuel direct drop in replacement performance fuel pump for the GS400? I know the pump is inside the tank, is it difficult to change the pump? what size of injectors will I need?



4/. Vortech makes 7-8 different size SC, which one you think I should use?



5/. Anything else I should be concern other than the common things like putting in a header, high flow exhaust system to allow more flow, put in a intercooler to avoid detonation...etc?



thanks in advance
Joe

jcat_350

i didnt look through your entire post because of the length but i will tell you these main points:

Dual supercharger setup is useless. One big one is better than 2 small ones.

www.lextreme.com, he's a member here and he makes a fish bracket to hold a centri s/c for your engine.


I would suggest using a vortech S-trim. Don't forget to add a tranny cooler and even VB upgrade as the stock tranny doesn't hold much power/torque.

daihap133

I would think two 15CFM SC would reach the max boost earlier than a 30CFM SC in the RPM range, so the boost would kick-in earlier, that's why I am thinking of a dual SC setup, may be I am wrong...

speedaddic

iTrader: (10)

there's not much lag on a vortech...you just want to stomp on it and get squirley or what? How much boost do you plan on running? How much access/experience do you have to make the right pulleys and such?

Walbro makes a replacement high flow intank pump that's pretty much drop in but you have to solder 2 wires. Injector size depends on how much boost. Stock gs400 injectors are only 240cc..

daihap133

I am thinking a mild boost from 8-12 pounds since the engine has 140K in it already.

About the pulley, it turns out(I think) they are all the same, so all I need to do is to find a longer belt and a tensioner pulley and redo the routing.

About the fuel pump, I can do the soldering, no problem, but I don't know how hard or easy is to access the fuel pump in the 400, some post here said there is an access panel behind the backseat, all I need to do is remove the backseat and unbolt that panel. Another guy in that same post claim he DID NOT see that panel, he have to drop the fuel tank. I guess I have to remove the backseat and find out what's the real deal is.

daihap133

about the boost to kick in earlier, I am hoping two sc can built up the boost much faster than a single higher flow SC could, may be 1000RPM earlier? possibly?(Just a thought)

add something like a wastegate to bypass the boost when it reach the dangerous level.

I also want to mount a second alternator(>150Amps) to juice two batterires, they are for powering 20-30 peltier panels(those little 1.5" x 1.5" things to cool down the cpu in your pc on top of the cpu), these panels can suck heat on one side of the panel and transfer it to the other side , upon max current draw(6-7Amps) by these panels, they can turn the cold side to -10 to -40C , this way, I can cool the intake air to near or almost 0C( I am hoping), much cooler than a intercooler can do.

Assuming one panels draw 7amps, 20 panels will draw 140amps, 12.6V * 140 amps = 1764watts, 1 hp = 764watts, so 1764watts = 2.30HP draw from the engine to drive this alternator(neglecting efficency - heat.friction lost), not bad for a 2-3 hp lost, I can cool the intake charge to near freezing temperature.

speedaddic

iTrader: (10)

fuel pump is easy.. remove the bottom back seat, you'll see a cover on the driver's side. Its held on with 3 10mm nuts. remove that and you'll see the top of the fuel tank assembly. You'll see a yellow clip on where the hose goes into the assembly. Remove that with a flat head screw driver, pushing it towards the passenger rear door direction. Pull the hose straight up, then remove the multiple 8mm nuts holding the fuel pump assembly. Then you have to pull that assembly up CAREFULLY and unclip the float (you don't have to but its easier). Remove the hose connected inside the tank that goes to the Fuel tank assembly. Now you'll have to pull the assembly apart and install the new pump.

evil00017

Has anyone actually used the lextreme bracket for a GS400. It says it should work with little or no mods but has anyone actually done it?

Rippaflow

iTrader: (4)

That's what she said.

StealthGS

iTrader: (2)

lol !! Ha ha

daihap133

First of all, the thing is only the bracket is supplied, you still need to find or make the plumbing parts(intake tubes) to work with the SC that you are usiing. Second, that bracket from the pic shown is cut from a flat piece of metal with no reinforcement, I am afraid it might warp or start to curve after a while, and therefore I would rather make my own SC mounting bracket.