Back In Action

[spf_lexus]

Hey fellas, its been quite a while since I last contributed to the forum. The last year+ I spent finishing up my last 2 semesters in college, started my job hunt and its been extremely stressful and busy. I ended up selling my supercharged SC400 and my project LS470 a while back so I could focus.. and to stop the hemorraging of project funds lol. Anyway I graduated Colorado State University of Pueblo last August for with my bachelors in Automotive Industry Management, minor in Business Management. It ended up taking me a solid 7 months to finally get a decent job. I was offered a job working for Ford as a technical service engineer at the Ford technical hotline in Allen Park Michigan. The work is stressful and not for me but I needed to try it out. I am in the process of actully moving back and putting together a business plan to start my own online business.

Anyway I have been out here 4 months and now I am getting the itch to go fast again! I bought Davids white GS400 4 months ago and after seeing nothing bus domestic pony cars on a daily basis.. I want my blower back on!

I learned my lessons the hard way when it comes to being boost greedy and popping engines so I am planning a very conservative 3-4psi setup since this is the weaker VVTi engine. I love the power already but its not enough to have any real fun against these new 5.0L mustangs, commonly modded WS6's, vettes, you get the picture.

Anyway I am about to get a complete exhaust fabbed up as a start, just need to locate a skilled shop that I can trust (people are not too fond of imports out here). I already have an HKS axle-back 2.3" mufflers and plan or run the following from the rear mufflers to the headers (already have all parts waiting install):

-Burns stainless 2.25" 304 stainless steel X-pipe splayed inlet, parallel outlet.
-2.25" stainless straight pipes deleting front resonator and 2 post resonators.
-Two 2.25" 45 degree mandrel bends
-Two 2.25" 90 degree mandrel bends.
-OEM CAT flanges and OEM post o2 sensor bungs

After speaking with Vince @ Burns stainless, this system should really open up the flow without affecting low end tq as so many custom systems do on these vehicles.




My big Problem: Getting "The Fish" bracket to fit the GS. Bracket install is usually a very straightforward affair but due to Lexus locating the ECU exactly where the blower would sit, it would require relocation. I have searched, and searched and searched for examples of relocation and no luck. All the known supercharged setups used the RMM or SRT designs which locates the bracket on the pass. side. (different bracket as well). These companies only produced a limited run of setups so buying a bracket from them is out of the question. If anyine has seen, or performed an ECU relocation, I would love to hear how it was done!

I am glad to be back, its been a long time my friends.

 

[4U2QUIK]

any chance of throwing the ecu in the fenderwell like they do with a lot of the 240z swaps.
btw, Should be starting up your old 4.7 engine soon.

 

[spf_lexus]

I think its possible but I am hesitent to start cutting until I have proof that it will fit. I would pay cash money for a picture of this installed and routed but it seems as though I am on my own with this one . The loom has some slack in it, but I really need to man up and take the ECU box apart to see what kind of slack I am really dealing with.


I am guessing David sold you the engine? Thats great news man, congrats on the purchase. It was built by a very skilled engine builder. I sold it to David a while back. I gave him a call last week and he totally forgot that he bought it off of me! haha. Are you planning to put a manual trans behind it?

 

[spf_lexus]

Its been a while but I have made some progress. Intercooler is installed, fish bracket installed, ECU relocated to the fender side frame rail, suspension fully build (minus LSD), exhaust completed, supra TT brakes swapped, steering stiffened.



Intercooler installed, very hard to notice.. great for a DD.



B&M polished transmission cooler. Rated for pulling 20,000 pounds!



Had to fab new hood latch braces. They look weak but its very ridgid.



My sidekick Elvis.

 

[spf_lexus]

Fish bracket installed. This is the 3rd Lexus that has seen this setup (GS, LS and SC). Notice the huge ECU loom? Yeah the ECU is exactly where the charger sits so relocation was a PITA.



Solid steering rack mounts (modified battle version SC mounts).



The pride of my exhaust: The Burns Stainless 2.25" X pipe. Talked with Jack Burns in person about my system and he told me that I should be able to squeeze 500BHP out of it w/o compromising top end.



Rest of the system: 2.25" 304 stainless mandrel, HKS Hi power mufflers, OEM cats, PPE headers, dual wideband bungs installed. Factory exhaust hangers retained.



PPE headers, thermal coated.

 

[spf_lexus]

Procharger P1 mocked up.



Very tight fit. Will need to ditch the OEM fans for some low profile SPAL's and the rad will need to slide over 1-2". Intake for the blower is VERY VERY tight. Either I run a filter or screen directly at the blower inlet, or a use some neoprene flexible ducting down into the fender.



Tein Flex coilovers (16k/12k).



Ikeya Formula rear upper arms:



TRD sways.

 

[spf_lexus]

FIGS Engineering spherical caster arms.



Tom's rear six link kit:



So far I have all the supporting mods that I was shooting for (except LSD which is coming).

The rest of the to do list:

1. Fab some cleaner blower spacers out of aluminum.
2. Install the rest of the intercooler piping.
3. Send the procharger off for new seals and bearings. (bearing noise and oil leaks)
4. Install my Tial BOV and Tial wastegate.
5. Wire up the windebands (both banks for accuracy)
6. Install low profile fans.
7. Fab a low profile box for the ECU.

One thing Im planning to do differently on this build is the addition of a waste gate. I know most people freak out when they see a centri blower with a gate but let me explain. I only want 5-6psi max on this setup but I would like as much mid range and low end as possible (already sounds like the centri is the wrong answer right?) Well the plan is to pulley down to say, 10-12psi (just below max blower RPM rating) and then set a waste gate to 5 or 6psi. This will give me quicker spool due to the greater step up ratio (smaller pulley), and MUCH more torque. Most people assume that this will "kill" the blower faster but this is false. If the smaller pulley size is still within the bearing RPM range, then no damage will occur, albeit "slightly" increased wear. Also, there is no real heat soak issues to worry about with this setup and the parasitic loss with a 10-12psi pulley isnt much higher than a 5psi pulley. In other words, a gated centrifugal blower with an aggressive pulley can mimic a properly sized turbocharger's hp and tq curve.

 

[4U2QUIK]

I am guessing David sold you the engine? Thats great news man, congrats on the purchase. It was built by a very skilled engine builder. I sold it to David a while back. I gave him a call last week and he totally forgot that he bought it off of me! haha. Are you planning to put a manual trans behind it?

Yup I picked it up off of him almost a year ago, It's already in the supra with a r154 behind it. I ran into a few little issues (someone forgot paper towels in the coolant runners, and nuts in the intake!) But it's all taken care of now.

also good to see you are running some figs engineering parts! Both they and I sponsor Joe McGuigan in the proam drift circut.

 

[JustenGT8]

Some nice suspension bits, should tighten up the ride.

 

[spf_lexus]

I have a question:

I am planning to adapt a return line for my returnless fuel system with a rising rate regulator and a walbro pump to solve my fuelling issue. Would I have to re-wire the pump for 100% operation with ignition present? Or could I leave pump circuitry alone? Also, I have read that some people were ok with the stock fuel system at 4-5psi of boost. Anyone know if this is accurate?

 

[gloverman]

Do the GS have the fuel tank over the driveshaft like the IS200 (altezza to us) and use the internal fuel return system to draw the fuel from the other side of the tank? I see they have the filter in the tank with the same fuel pump and filter assembly as the altezza but have a different regulator but I suspect it still has the fuel draw from the other side. The setup looks just like the altezza but info and pictures can sometimes be a bit deceptive. We have modified several altezzas from returnless to return style when running lots of boost. After several different setups we found one which worked really well.
Im not really sure that you need to move away from the returnless system with the boost you want to run. The pressure differental across the injector will still be well within working conditions. Im sure there will be some other ideas on this one. And how much more than standard where you hoping to run?
Im not even sure if rewiring the pump is necessary. I was going to say for the power supply to just bypass the Resistor like the Celsior but that might not work for you. Does your car run a fuel pump ECU? If you remove the pump ECU then the engine ECU will throw a fuel pump circuit code and cause issues.
What ecu are you thinking of using? This will determine the fuel system more than anything else. And what injectors?

 

[gloverman]

The GS has the same ECU position as the JDM 170 series crown. Ive just swapped a crown loom for a celsoir (LS400) loom which has the ECU inside the cabin and exits the engine at the rear instead of the front. Swapping around to suit different conversions.

 

[spf_lexus]

Gloverman, I havent decided through and through to take the return line route. I know some people have been somewhat successful with 315cc's on the stock ECU and I have heard that some were ok with very low boost with no fuel mods at all (3-4psi).

I think the easiest would be to get some 7MGE injectors (295cc versus 250cc stock). And this is my DD so preferrably I would like to be CEL free. I guess since I will be running a wastegate I could always set the spring to like 3psi and then slowly increase to 5 or 6 psi. The car will have dual bank widebands so I guess I could monitor trims under WOT while I step up boost 1psi at a time.

In addition, I wonder how much real fuel enrichment is taking place when my 50/50 water/meth kicks in? With the meth, I could be just fine at 5 or 6psi. I guess i'll just have to take it slow.

 

[gloverman]

You do know the VVti engine takes a completely different fuel injector to the early engines. 7m injectors wont fit without machining the intake manifold.

What guys have done with the early engines almost doesnt apply to the VVti engine as they are a very different beast.

One advantage of the VVti ecu is they have 25% fuel adjustment each way on the oxygen sensors. If you have a fault with the system this drops to 20% and when it gets to 20% resets to zero for a little bit before trying again. And proper monitoring with the scan tool.

 

[spf_lexus]

Thanks Gloverman, great info. Never really considered the vvti vs early interchangeability. A lot of guys on club lexus were dropping in injectors but I guess I need to know exactly which ones they referred to. I find it interesting that the stock injectors have been known to support 400bhp and 400btq and im pretty close to this (450bhp is the end goal). I believe that 3 or 4 psi would be just fine on the stock fuel system. I want 5 or 6psi which makes it a little harder. I could prob eek out the rest of the required fuel with methanol but I really dont want to fall on the meth as the fix. When the meth runs out, im running lean... no good.

What about opening up the stock injectors slightly? Take a stock 250cc and bore it out to a 300cc? I have heard some people had success going this route.

If I can sort out a way to jump the fuel pump at 100% w/o a CEL then I will most likely go that route: walbro + stock injectors + 12:1 FPR + custom return line. I know most people dislike this "bandaid fix" however I ran this setup for 2 years w/o any issues and it yielded better than stock MPG.

 

[gloverman]

If you wire after the fuel pump ECU using the Fuel pump ECU output as your trigger and then feed your constand 12 volts switched by that. These ECUs are clever but not that clever.

 

[spf_lexus]

Great suggestion! Basically use the fuel pump module output circuit (feeding the pump) as a trigger for a relay which commands 100% operation.


Do you know if running the fuel pump at 100% output will shorten pump life? Arnt the early pumps set in 2 stage? 50% output and then 100% output? If so than that answers my question. I would also venture to guess that a walbro @ 100% output may be a bit noisy.. maybe a Denso pump instead?

 

[gloverman]

Considering walbros have a maximum usable pressure of 60psi and the VVti has a base pressure pretty close to take I wouldnt be using a walbro. I always use the highflow denso pumps. Next question is will it fit into the tank assembly? Have you seem the unit inside the tank on the GS?

 

[spf_lexus]

Just replaced the main fuel filter last week and there is lots of extra room. The oem pump looks identical. Anyway I mocked up the walbro and it fits perfectly. Thanks for mentioning the 60psi limit of the pump as I doubt it will work well with my 12:1 fuel reg. I need well over 60psi for it to do its job. BTW thanks for all the help Gloverman
.
Would a stock denso supra 93-98 pump pull its weight?