Project Thread Supercharged GS430

[Lextreme II]

So here is the jist of the install:
3" polished aluminum pipe
12x24x3 intercooler
ATI P1SC With Lextreme Bracket
autowerks bypass valve
walbro 255 hp in tank
3.9" pulley
ngk v power bkr 7e plugs
stock everything else

custom made front hood support bracket because I had to remove the original for the front mount, as seen in pictures.
had to do a bit of grinding on the front, near the head lights where the intercooler pipe comes up and down near the end tanks where the pipes come in to meet the intercooler.
The biggest issues I found was trying to figure out the idle issue like we spoke about and the intake pipe to the procharger. I had to do A LOT of fine trimming and grinding to make something work. You don't see it in the picture yet because I haven't got the filter. Also the horns need to be relocated, as seen in picture. I will update you with the pic. I only want to run somewhere around 4-6psi that way not having to worry about detonation. I'm not planning on driving it until i have a wideband and boost gauge. You say that with the 3.9" I should be somewhere around 6psi?

Erik P.

 

[spf_lexus]

Nice GS, good to see the FISH is getting some love. I have the exact same setup but on the 1uz. I was seeing 1psi for every 1/10th of an inch pulley increment. So, a 3.60" pulley on my P1SC gave me 7psi on the exact same sized intercooler you have (12x24x3). Given that the boost pressure (resistance) changes with larger/smaller displacements your 4.3L may be more like .9psi/1/10th inch pulley increment. I would say 6psi max for your setup could be done using the same 3.6'' pulley, maybe a 3.7''.

As for the idle issues I can help you. I ran mine with a crappy idle for around 6 months before I got fed up. the problem is that a BOV and a bypass valve can both be used but the real trick here is to have one with super fast actuation. A simple bosche BPV from a VW beetle turbo worked excellent and instaltly brought back a clean 650rpm idle. I really wanted a BOV so when i bought a TIAL I had to order a special "supercharger" spring and this 3psi spring replaced the 7psi that came standard. This spring was not even advertised on their website so it was a real can-o-worms. The minute the soft spring was inside the actuation was insanely fast and brutal sounding, but mostly a personal preference as both work just fine. The whole purpose is to open immediatly after a throttle decel and completely open at idle. With a closed BPV at idle the unit is blowing air against a closed throttle plate, causing the blower to want to spin backwards and stall out. Recirculation is really optional, good for noise suppression more than anything.


Hope this helps, keep the pics flowing.

 

[erikbang]

Thank you David for posting the info!

Thank you SPF! I played around with the idle issue for a bit last night and found that with the bypass disconnected from vacuum it idles fine. David had a good idea by trying to regulate the vacuum to the valve because the valve was opening up to much and was too slow to respond. I really would like to get out there and drive the car but I need to get the gauges.

Was the boost you are seeing on your 4.7 or 4.0? It was a 3.6" right?

 

[Lextreme II]

Nice work... keep it up and keep us posted.... I think SPF was referring to 4.0

 

[spf_lexus]

Yes all these numbers were found using the 4.0L. I have not tried out my 4.7L yet so boost will no doubt differ.

I remember buying a 5psi spring thinking that would help sort the issue but like you said the actuation was still too slow. The idle would be stable since the unit would crack open a couple mm to bleed pressure but when i jammed on my brakes at a red light my car would die because the vlave was not opening up fast enough! You'll absolutelt love the brutal power, made any runs yet?

 

[erikbang]

Yes all these numbers were found using the 4.0L. I have not tried out my 4.7L yet so boost will no doubt differ.

I remember buying a 5psi spring thinking that would help sort the issue but like you said the actuation was still too slow. The idle would be stable since the unit would crack open a couple mm to bleed pressure but when i jammed on my brakes at a red light my car would die because the vlave was not opening up fast enough! You'll absolutelt love the brutal power, made any runs yet?

I'm a little scared to do anything without a wideband! I would rather error on the side of caution but from how crisp the throttle is, I can tell there is a ton more power there! Guess I'll need a limited slip next...you're running a wideband, right? which one do you like? I've been looking at the innovate lc-1 and the lm-2

 

[stilltippin]

Hey Erik, its 3uzfte from CL. I just wanna say again that this thing is pretty sweet. Yeah, you will definitely need a LSD, you can do some part sourcing and do it for pretty cheap. Look forward to the results.

 

[Lextreme II]

Welcome CL members.... We love the GS

 

[erikbang]

Hey Erik, its 3uzfte from CL. I just wanna say again that this thing is pretty sweet. Yeah, you will definitely need a LSD, you can do some part sourcing and do it for pretty cheap. Look forward to the results.

Hey...nice to see you over here too! Thanks man. You'll have to give me a line on where to locate the lsd from. I know before there was zero fun factor with the 1 wheel peel.

 

[erikbang]

update

No news is good news right...been a bit pre occupied

So update:

Took the car out for a drive a few times and this is what I've got, about 1-2lbs with 3.9" pulley. Car pulls good for such low boost, I do have my eyes on some 315cc injectors and no I still haven't got my wide band. The power delivery feels very good...like the torque is flat as a table, honestly I was surprised at how much difference such little boost did. Again I was not expecting it to net any results with that low of boost pressure...I need an lsd! I haven't made it to a dyno yet but when I do get all the details sorted I will post with results.

As for belt slippage...I can't feel anything with regard to power falling off under boost. There is a lot of belt coverage on the pulley so I wouldn't think it would be an issue. I think a 3.75" would be a perfect size and I don't expect it to slip but who knows.

I am having one problem...under cold start up I'm getting a knock code of p0325, bank 1, pulling a ton of timing. First thought was lean condition but under closed loop, but while it's under idle? I know wide band...I also was thinking that because the ati p1sc is gear driven, loud and rattles, it could be causing translational knock. Nothing under driving. Far fetched I know but after the car warms up to operating temp, you turn it off, then restart 1 min later it runs phenomenal! I'm very happy and its not done yet. I can't wait to get the wideband and fuel to see how it runs and then go for the 4-6lbs. Any feed back would be greatly appreciated.

I will post a few new pics of the intake I came up with for the charger. It was kind of space constrained but it turned out good.

 

[Thermactor]

Hi erik, can you post those pics up? I wanna see! Thanks