kyle3481

hi guys
just wondering what will be the possible MAX NA HP for GS430???
i know that 3.76 supra LSD wont add any HP, but it sure does knock off some 0-60 time as well as the 1/4 mile time. so how about exhoust?? should i take away the resonators??? will it be very loud??? or?
how about intake??? what will be the best intake+ECU???? any problems with the car after installing the ECU???

thanks a lot guys

Guru

I'm going to start running a batch of tests on my car which is a GS400. I'll post the dyno results. I have an S-AFC II to fully tune the fuel curve after each mod. I plan to use an exhaust, cat free pipes and an intake. We'll see how much power we can extract..

Richie

400 should be doable with some nice mods I think.

TerryTCL

i say you could probably squeeze about 150 additional HP out.

1) headwork
a- port and polish intake and exhaust ports
b- valve bowl rework
c- 5 angle valve cut
d- shave off a couple thousands of an inch from the head
e- combustion chamber rework
f- upgraded valve springs and retainers

d+e will raise the compression
f will let you raise the rev limit

2) intake manifold and throttle body rework
overbore the throttle body
port match and extrude hone the intake manifold

3) custom cut camshafts

4) high flow headers

5) remove catalytic converters

6) enlarge the exhaust piping from cats to Y

7) better fuel and spark mapping

8) high octane fuel

------------
extreme

9) high compression custom pistons
10) lighter forged rods
11) lighten / balance / knife-edge the crankshaft
12) individual throttle bodies
13) extreme cut camshafts

cons: harsh idle, poor driveability, high gas demand, high tuning demand
pros: lots of pure all motor power on a small displacement V8

TerryTCL

oh and by 150 hp...

i mean at the wheels

Richie

I think no one has ever gone that far on a GS.
Would be cool to see though. Imagine opening the hood and seeing 8 throttle bodies........

Mr Johnson

I dunno.... You're trying to build an M5 starting with a smaller motor. BMW needed a lot of engineering to get to where they are I just don't think some of this stuff would be anywhere near simple... heck mildly complex even.

It would be fun to try though.

squarehat

Very apt analogy, indeed The ///M crew knows what they're doing, most of the time You don't want your 3UZ turning out like some of those early E46 M3 motors

TerryTCL

i think the M5 engine still has a lot of potential in it.

"high performance engines" are de-tuned to cater to a balance of power and driveability.


get the UZFE engine to the point of harsh idle, poor driveability, high gas demand, high tuning demand... then you've got one bad mother of an engine...

Richie

Indeed, I have seen some german tuners offer 500hp NA kits.
That is 100 hp more at the flywheel.

kyle3481

thanks a lot guys for all the inputs....
i just want to start some simple NA tune here....
anyone had removed their resonators or change it to a thicker pipe??
or how about header work??? anyone custom made one???

JBrady

This type of a question MUST be qualified. With enough money and smarts applied the basic engine could probably be re-worked to produce 700+hp at 10,000rpm. Now, this engine would NOT be something usable in a street drive Lexus, BUT... it is theoretically possible.

My guess is that your question is: How much N/A power can be added to a Lexus 32v V8 using bolt on modifications only?

Well, this still leaves some undetermined areas. Bolt on could mean changing camshafts but lets NOT use that option. I could mean porting the heads, larger valves, re-worked intake... again, let's assume the stock long block assembly WITH both the intake manifold and the factory exhaust headers intact.(to remove the headers is a HUGE PITA)

So, we are left with intake mods to the throttle body. Exhaust mods from the headers. Electronics.

Both intake and exhaust mods have an effect on one another. You cannot fully extract all the potential from one without the other. SRT offers an intake that is probably as big as necessary to feed any mods considered here. They claim 22rwhp and 30rwtq. This is with stock catalysts and stock exhaust except for the rear mufflers in place. This is probably all the intake you could use. Exhaust wise is another story. I have been working with an engineer and computer modeling several Y pipe designs. There is probably 20rwhp to be had on a GS4xx with an optimal exhaust starting at the catalysts. Maybe 10rwhp more without the cats. These are estimates but reasonable ones.

The last component is electronics. The stock fuel cutoff is at 6300rpm. This is WAY too low for a short stroke 32v V8 with forged crankshaft and 6 bolt cross bolted main caps. 7000rpm would be safe for occasional bursts. It is hard to say how effective the cam profiles would be in this range but comparing this to a stock Ford 5.0 with 2 valve heads, tiny valves, tiny exhaust ports and a stock peak power at 4400rpm... This engine was rated 225hp which = about 180rwhp. My old mildly modified engine made 249rwhp at 4600rpm (apx 300bhp) another with a STOCK cam and much better heads and manifolding made 280rwhp at 5600rpm (apx 340bhp) on a camshaft supposedly optimized at 4400rpm

So, our engines have a peak output at 6000rpm with restrictive manifolding... improve the manifolding, raise the rev limit to allow 7000rpm operation and there is probably another 30-50rwhp to be had. So, until someone actually does this... we can only guess BUT using educated guessing is reasonable and the above details indicate that apx 80-100hp could be gained. This much additional may not be attainable with the stock exhaust manifolds. Check my previous threads in the LS forums for pictures of both the old and new style (through 2000 anyway) exhaust manifolds.

Richie

Andrew, keep us posted on whet you are going to do!!

kyle3481

hey jbrady
thanks a lot for the help man
so u mean IF i remove my resonator and possibly i will also do a Y-pipe (with larger diameter )
it will POSSIBLY extract 10HP??? or lesS maybe? now i am on the step of doing a Y-pipe...
thanks a lot
i will keep u guys updated

roenick7

Yes I have had the resonators removed (the first of three) I also had an H pipe put in. It is seperate exhaust now and has added 30 HP. The sound is awesome yet not to much for the wife. It is 2" all the way to the RMM 2.5" catbacks.
silverman_gary@hotmail.com