Thinking Low Boost Turbo
Thread Starter
Lexus Champion
Joined: Feb 2001
Posts: 3,124
Likes: 32
From: Texas
Thinking Low Boost Turbo
I am thinking about building a low boost turbosystem for my engine.
Since the stock block has weak rods and cast pistons AND since the stock 5 speed is not rated for the torque a higher boost system would make this is IMO the best solution to more performance.
5 psi of boost if properly designed should make around 400hp (320-340rwhp). If the power was kept at that point and not raised further the engine and transmission stand a good chance of providing reasonable reliability. Since I have the skills to build this myself I can minimize costs.
It does not make economic sense to target higher than the above power levels as a complete engine rebuild with upgraded parts AND a DIFFERENT transmision solution, not to mention the ability to properly tune the application, would be needed for reliabililty. Our cars are fun and reasonably fast BUT compared to more and more new cars we are getting slower by the minute. 400hp is enough to run with MOST cars respectably not to mention the fun potential.
Since the stock block has weak rods and cast pistons AND since the stock 5 speed is not rated for the torque a higher boost system would make this is IMO the best solution to more performance.
5 psi of boost if properly designed should make around 400hp (320-340rwhp). If the power was kept at that point and not raised further the engine and transmission stand a good chance of providing reasonable reliability. Since I have the skills to build this myself I can minimize costs.
It does not make economic sense to target higher than the above power levels as a complete engine rebuild with upgraded parts AND a DIFFERENT transmision solution, not to mention the ability to properly tune the application, would be needed for reliabililty. Our cars are fun and reasonably fast BUT compared to more and more new cars we are getting slower by the minute. 400hp is enough to run with MOST cars respectably not to mention the fun potential.
I would agree! I bought an M90 supercharger (OEM on the Gran Prix GTP) to do the same thing, but was eyeing the 6psi mark -- it seems 7 psi is where more issues can start to pop up (fuel injector/pump upgrades, stress on the rods, need for an intercooler, etc) and I wanted to steer far clear of that for dependability and cost reasons. Going my route, I expected to spend about $5-600 on parts and installing myself, then selling my K&N FIPK to pay for the dyno tune of the Apexi SAFC. I don't know as much about the turbo option, so I'll let the others (JeffTsai?) chime in about that.
I wonder if you could pull a turbo off a Volvo in a junkyard for $50... Would you need an intercooler? Hit e-bay for the boost controller, wastegate, blow-off valve, etc.?
I wonder if you could pull a turbo off a Volvo in a junkyard for $50... Would you need an intercooler? Hit e-bay for the boost controller, wastegate, blow-off valve, etc.?
Thread Starter
Lexus Champion
Joined: Feb 2001
Posts: 3,124
Likes: 32
From: Texas
I would agree! I bought an M90 supercharger (OEM on the Gran Prix GTP) to do the same thing, but was eyeing the 6psi mark -- it seems 7 psi is where more issues can start to pop up (fuel injector/pump upgrades, stress on the rods, need for an intercooler, etc) and I wanted to steer far clear of that for dependability and cost reasons. Going my route, I expected to spend about $5-600 on parts and installing myself, then selling my K&N FIPK to pay for the dyno tune of the Apexi SAFC. I don't know as much about the turbo option, so I'll let the others (JeffTsai?) chime in about that.
I wonder if you could pull a turbo off a Volvo in a junkyard for $50... Would you need an intercooler? Hit e-bay for the boost controller, wastegate, blow-off valve, etc.?
I wonder if you could pull a turbo off a Volvo in a junkyard for $50... Would you need an intercooler? Hit e-bay for the boost controller, wastegate, blow-off valve, etc.?
Unfortunately there are no junkyard turbos are available for my plan.
Very cool.
Could you share your parts list.. even if its a wip..
Details like turbo manufacture and model.
Will an intercoler be needed at 5psi?
Lastly o.t...any progress on your Y pipe, as PPE is nearing completion on the shorties.
Could you share your parts list.. even if its a wip..
Details like turbo manufacture and model.
Will an intercoler be needed at 5psi?
Lastly o.t...any progress on your Y pipe, as PPE is nearing completion on the shorties.
I guess you could get away without running an IC but why? IC are so inexpensive, it should be mandatory. No need to risk your motor for a few bucks. Fabricating IC piping can get expensive when you are paying a shop but doesn't have to be, especially if you are doing it yourself. As far as ebay turbo parts, I wouldn't go cheap on vital parts. It is not worth it. At the end of my 2JZ NA-T build, I decided to go with a replica HKS gate because I was excited for it to be done. In the end, it leaked and in the end after a few months it stay stuck open. For what reason I do not know and I really didn't care, I tossed it for a brand new Tial 44mm gate 
I would invest in the best engine management I can get. AEM FIC 8 or Greddy EMU?
On the VVTI 2JZGE (weakest rods of all 2JZs) I've seen blocks with 100,000+ miles boosted but I think the key is engine management. I notice the ones that hold up the best and make the most power, obviously, are the standalone ECU tuned motors.
I would invest in the best engine management I can get. AEM FIC 8 or Greddy EMU?
On the VVTI 2JZGE (weakest rods of all 2JZs) I've seen blocks with 100,000+ miles boosted but I think the key is engine management. I notice the ones that hold up the best and make the most power, obviously, are the standalone ECU tuned motors.
There are many members running close to 400whp on stock internals and transmissions, why are you targeting such a low gain? I don't really see the point in 320whp, maybe more on the 340-360whp. Either way I'll give you props, but 320whp is just not enough to even consider all the fabrication you'll have to go through. Unless you go remote mount, quick, simple, easy, and on top of all, cheap.
jbrady, you're right...after a certain amount of boost, its just not economical for us...I've got way too much money in my stock engine right now...I can't imagine when I rebuild it how high the bill is going to get.
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Thread Starter
Lexus Champion
Joined: Feb 2001
Posts: 3,124
Likes: 32
From: Texas
Intercooling is not required at 5psi but always a good idea. I have yet to decide if my first design will incorporate one or not.
The Y pipe is completed... in my head
... just need to build it. If someone has a stock GS4xx Y pipe they can lend/ship to Houston that could speed up the process. My end goal here is to extract as much power from the STOCK design and assemblies and limitations as possible to keep our rides power competitive AND do it as the lowest total cost. Currently nitrous fills that space but with bottle refills that changes over time. Power target is 330-350rwhp which is 100+ over stock.
Question. Is there anyway to reduce the amount of PSI that the supercharger produces other than changing the size of the pulley? Perhaps through the tuning? Reason being is if someone had a newly acquired SC kit and it only came with say...a custom pulley that yielded 8psi and that individual only wanted a 6psi power level without having to incur additional costs to get a (larger) custom pulley fabricated.
