Question About Forced Induction

[adeel]

Hi

I am new to this forum, dont own a SC yet, but I am planning on picking up one this spring.

I was wondering what the reliability of the car is like after you introduce forced induction of any kind. I know that the 2JZGE is a very strong engine, but what kind of boost can one run without compromising the logetivity of the engine and transmission.

Also, is the automatic able to handle the higher power? Are there other upgrades that the car would require after the turbo?

Is there a particular model year SC 300 that is better for tubo application? Is there a harm in adding a turbo to a higher milage car? say....over 90000 miles. What is the upper threshold of the mileage that I should be looking for if I am going to add a turbo?

Any input would be appreciated

Regards

Adeel

[AWJ]

Reliability is good if the install is good and quality parts are used and the tuning is correct and no mistakes were made.

The auto tranny is weaker unless you get a 98 or newer, but then the rods are weaker. What's worse? I have my own opinion on that.

We've discussed all of these things a great amount in the past. There are many threads - hit search and you will be pleased.

I have hit 20 psi before all stock internals. Is it safe to do that? NO. 10 pounds daily is no problem. Above that, and you need to be wary of the tuning, not that lower than that won't require more fuel.

I always say 1995 is the model year to choose to turbo. 98+ is vvti and obdII (I think the 96+ are obII). These things make it harder but not impossible. There is nothing wrong with a 92-94 model either though.

As far as mileage is concerned. Check compression. Make sure all systems are operating correctly. If you plan to pull the head anyways, make sure the valves and all that are nice. They probably will be, but might not be depending on who used the car before. There are turbo ge's approaching 200,000. Then again, there are turbo ge's that didn't make it too far out of the shop.

My advice, whatever you end up with, keep your wallet fat or be prepared to get creative.

[adeel]

Thanks for the input.

Ill look around for a good 95 then.

Will do search on the topic too, and then when I am close to the turbo project, I'll more than likely bug you again too. :)

Regards

Adeel

[SPORTcoupe300]

Hey AJ,

What problems does the OBD-II in 96+ SCs present?

I gave it some thought and see no problems as far as the OBD-II is concerned.

I've got 125K on the car right now, and I know that putting on a turbo at this point would be pointless.

So I'm saving money for a rebuild and DaveH's beginner kit.

I'm planning to start off with very mild boost (6psi) and use my SAFC-II with stock injectors to deliver the gas it needs.

In the future, I'll be replacing injectors, installing a pump, etc.

What do you think of this?

~Alan

[AWJ]

I wouldn't rebuild a motor that didn't need it. A 125k motor probably is just fine. Test it though. It probably won't hurt to have the head done though with new valve stem seals, valve checked, angle job and maybe light porting - deck. At 6 pounds, I'd just keep 10:1.

ObdII is just more wires, sensors, systems to trick. Not impossible. Just more expensive possibly. Ditch Safc and get something that will read boost. Or keep it and get another unit that will read boost - like avc-r with safc, or injector controller, etc.

[SPORTcoupe300]

I was thinking that at 6 psi I don't really need any fuel-management that reads boost.

I can just use the SAFC and get it properly tuned.

Only problem with that would show up if the wastegate didn't do it's job, and I got more or less than my expected 6 psi at some point in time.

This is quite a bit in the future, so I'm not too worried about it yet.

When I gather enough funds, I'll be looking more closely at the details.

[AWJ]

I understand your logic and I used to think the same way. Frankly, I feel the safc is nothing more than a pretty gauge set with quazi-real time feedback. There is no feature of the safc to see boost. So beyond any percentage adjustment over certain points of the rpm range - the fuel will be the same as set. Therefore the transition from vacuum to positive pressure is never seen. It would be better to use a boost dependant fuel enrichment device. People say mechanical fmu's are crap, but I would think this would be not a bad solution. I have never used one though. Better yet is a pressure transducer unit - take the haltech f5 for example - that will notice the transition into positive pressure, actually meter it, and then dump fuel depending on cut in and rate settings via potentiometer adjustment (ideally on a dyno with wideband). There are many injector controllers and other units that will do this.

Simple digital systems touts a unit that is "user friendly" as has cought my eye in the past. Basically, you are looking for units that boast 3D features. Where it will use three references as input. RPM, throttle position, and boost for example.

The fuel controller is only going to pull or add fuel where it is set. It will always be the same given rpm. Where boost might not be the same every time at any given rpm - causing a lean or rich condition. You go too lean under boost and... well - you've heard the stories.

[bean_8044]

Just had a few cents to add in if noone minds. First, i realize that the S-AFC isnt the best fuel management system, but it does have a few good points. It can read pressure from the AFM but the accuracy is dependant on the AFM. There is a slight delay, but you can do a 60 second record for a single sensor and you can see the boost changes through that also. As for running too lean, i figure that if youre on the razor's edge to where you might blow an engine youre probably not a street driver. What kind of situation would that have to be in for it to run lean like that? I mean, my boost comes on around 3k and it will continue to climb slowly after that, but if you downshift, you get into the fuel curve cause youll be at higher RPMs and the boost will rise. If you upshift, it would have to be something like 8k in second going into fifth gear and the turbos wont sustain that boost with the low RPMs anyways. Maybe im missing something, but im not too worried about the fixed fuel curve. You make a good point about the Haltech, but for me, a regular street person and sometime drag, the $200 Apexi is good enough for me

[AWJ]

Bean, it's a little different for you because you are running the 1jz with the turbo ecu from the factory. In that application, the safc does what you want. Pulls or adds a little here and there. The oem computer already accounts for boost.

Our situation is a normally aspirated motor with a computer and hardware that was not put together with boost in mind. There is no map for boost. We can add a 1uz flow meter that will meter a bit more air. But fuel dump should be accurately accounted for. You got a deal on that apexi. I've seen injector controllers for just a little more. I'd feel a whole lot better about running something that will boost dependant for the na-t application.

[bean_8044]

Yeah, good point about the ECU. I forget that the US is the only country without the Soarer. You can get the S-AFC Gen I pretty cheap since the Gen IIs are out now. The only difference is you can see the knock reading from the factory sensor and four extra fuel points at 200 RPM increments

[RollnNLuxury]

Hey i have noticed that alot of you guys "awj" ect have side mount intercoolers. Why dont yall have front mount ? Isnt it alot more effecient? Just wanted to know cause i was always under the impression that frount mount was the only way to go. Please feeel for to post what you think and let me know otherwise if i am wrong. thanks

[AWJ]

The sidemount works just fine for the amount of air I'm flowing. I haven't measure air temperatures - so I'm not sure if my set-up would benefit from a front mount. It was put together by toyomoto though. I suppose they chose that intercooler and it does the job. I like the hidden ic look as well. Then again, an aggressive fmic looks cool as well.

[bean_8044]

Its in the upgrade path for me, but my turbos cant handle the added boost right now. They should explode somewhere around 14psi and i havent quite gotten the AVC-R tuned just right yet. Side mount should be fine for 15 and below in my opinoin, although my friend with an RB20DET said his boost came on alot harder and spiked more when he got his monster hybrid FMIC installed

[SPORTcoupe300]

Thanks for the input guys.

I actually bought my SAFC-II for $250(used) so if I do decide to go the Haltech or e-Manage route, I can re-sell it and probably not lose anything.

Found out today that I might be out of a job soon though so I guess that doesn't help my boost dreams.

On a good note: Got my MagnaFlows installed a few days ago.

I promise I'll take pictures and write a few words.

To summarise: :D :D :D :D :D x10