Why are the GS owners with RMM Supercharger are Changing to Turbo

[Lextreme II]

I would like to know why are some of the GS400 owners are changing their FI system from supercharging to turbocharging?

 

[morris]

Well I can tell you for me, it was a case of not being satisfied with what the RMM kit could deliver. It really is limited to about 5-7 pounds of boost and then the belt starts slipping this was occurnign even with cogged pulleys. I got up to 389hp with the RMM kit, that was great for a while but then when I wanted to increase HP I couldnt, RMM was zero help in trying to surpass there advertised boost levels. So the only thing I could do was ditch the Supercharger and go to the turbo setup. Believe me if I could of stayed with RMM I would have.

 

[Lextreme II]

Morris,

I am digging this old thread up because I know u are making killer power now and with build motor too. Can u update us with your new ride and peformance? Was swithing from RMM to turbo a good move or its not?

 

[morris]

I would say going to the Turbo was definitely a good move. The car is very fast, and can be down right scary to drive. It will get sideways very easily even with the LSD and 285 rubber in the rear, if you punch it the worng way.


I dynoed at 428hp at somewhwere around 12PSI, I am now running 17PSI so I figure I am somewhere in the neighborhood of 500hp.

Next mod is going to be a bbk I found that now that I accelerate so hard I am braking quite a bit more. This causes the brakes to heat up badly and I have experineced brake fade at the wrong time. (cars in the bodyshop now)

But all in all I am happy, I got the hp I wanted no issues with belt slippage. I will say that I do misss the instant on power of the supercharger but I have learned to live with it.

 

[Lextreme II]

Nice work Morris. I must be fun driving a 500 hp GS400 isnt it? Style, Luxury and performance. I envy you....

 

[stevechumo]

Morris,

When you have your car back and ready, could you post some pics of your turbo system? It's because I want to get jealous with you like David...:veryhappy

My goal is only about 350 rwhp or around 400 bhp.

 

[jibbby]

Morris is that the stock GS400 transmission you are pushing an approx. 500hp with? I would assume you did something with your drivetrain, no? Just curious?.... 500hp on a 400 motor is good stuff.......congrats.

 

[morris]

I am out of town right now but wiill post some photos when I return home. There are photos on Clublexus. I think the post was turbocharged gs400, you could use that as keywords to do a search.

I destroyed the original tranny when I was around 389hp, so I am running a built tranny now that is supposed to be good for up to 800hp. It doesnt shift as hard as I would like ti to but so far it has held up.

 

[jibbby]

Morris try Upping the line pressure that should help with harder shifts....What built tranny did you use? Built stock like I am now doing?....

 

[morris]

Yea it is the stock tranny that was rebuilt for me with upgraded clutches and whatnot.
I think the company that did it was called transworld, it wasnt what I would call a positive experience. To up the line pressure it requries a VB modification right? or is there another way to acomplish the goal? The VB was supposedly upgraded I just expected harder shifts than it currently gives.

 

[stevechumo]

Morris,

How much did you pay for that rebuilt auto tranny? Did the price include the torque converter as well? Perhaps Mr. Lextreme might be interested so he wouldn't burn 2 trannies in 1 month. :veryhappy

 

[Lextreme II]

I am not sure the hp i am making. I need to drop my car off to Split Second and have them tune it. However, its running better everyday. I burned up two trannies already. As you guys know its very costly. My car ran few times at 18 psi, but daily 14.7 psi. Tell us more about your system.

 

[jibbby]

I thought LEX was dropping in the Th400 on that baby..no? I am too going for the stock tranny buildup and hoping for better results, performance, and hp holding capacity....Crossing my fingers.....

Morris I can't be certain about upping the line pressure on an already built tranny, maybe you should call those guys that built up your tranny, they should be able to give you the answers you are looking for.... That should help with your shifting

 

[stevechumo]

On Honda auto trannies, there's a shift cable connected to the tranny. It can be adjusted for harder shift or smoother shift. It jerks for harder shift but it's more responsive and easier for the ring gear to be broken. In Morris's GS, it shouldn't be a problem because it's strengthened already.

 

[Lextreme II]

John,

The TH400 is for my future SC project. Daily driver.... never 3 speed.

 

[jibbby]

Ohhhh, I understand now...I guess I can't keep up with all your projects..I thought you were tired of going through these stock ls400 tranny's and was going to put that TH400 in, and I was wondering what you were thinking? I am clear now, thanks...... So what are you doing with to your LS400TT Tranny situation if you don't mind me asking? Are turning down the boost...hehe:veryhappy

Hi Steve, I very much dought Morris got the torque converter with the tranny build... Those two are usually seperate animals........See ya

 

[bango]

Stock tranny that can beefed up to handle 800 hp is very interesting to say the least..This surely is an upgrade thats worth it...

 

[morris]

The tranny rebuild was 3k.

I already had a dragon torque converter with stator pump so that was a separate issue all together.

I'm pretty sure that the line pressure can only be upped by the VB adjustment, thats the whole point of doing it as I understand things

 

[morris]

turbo photos

here are some pictures

 

[morris]

more photos