Forced Induction mods before turbo

mods before turbo

i just inherited a completely stock 98 corolla (non-vtt-i). i've been looking into turbo setups for my old car (00 mitsu mirage), but it died on me. i need to know what is needed to run a safe turbo setup on stock internals. good engine management is a must i assume, especially with the high CR. i've read that the no-return type fuel system is a problem. i dont have any experience with those. could someone explain why it wont work well with turbo? i would also like to know what the max safe boost level is, what usually goes 1st under boost, what kind of injectors everyone is using, whether the stock pump is good for the max boost level on stock internals, and where i can get a turbo manifold made. if there are any mods (such as maybe a radiator swap or a thicker head gasket) that can be done to insure long engine life with turbo, short of forged internals, please let me know.

-Igor

talk to vortex about turbo setups on those hes the master...

Yea Vortex, Vamp, Losx and other in the board have some experience when it comes to this stuff, I could eventually learn about it cause I need info on boost too

So, you want to turbo the Mirage, right? If I were you, I would just swap in a 4G63T, they fit in without too much trouble end are a good engine.

With that out of the way, there are a few ways to go. Using an FMU is a fine and acceptable way to turbo a car, *if* the fuel system is a return type and *if* you're only boosting to around 6 to 7 psi. Otherwise you must have at minimum a piggyback to control fuel. You'll also need something to retard timing under boost, the MSD BTM (boost timing master) works well.

With a fairly high compression engine, you really don't want to boost much over 6 or 7 psi. The first thing to go? Can be a number of things, pistons and rings take a real beating if you're not careful, along with head gaskets.

Upgrading your fuel pump is a very good idea, and if you are going to use a piggyback then injectors are needed as well. Probably injectors from a DSM would work great for you. As for the turbo manifold, you can probably use parts right from the 4G63T...

If you mean that you want to turbo the '98 Corolla, then forget most of what I just said.

*edit* Hmmm... after reading your post a couple more times it seems like you mean that your Mirage died on you and you want to turbo the Corolla. Personally I would still recommend swapping a 4G63T into the Mirage and keeping the Corolla as a daily driver. However, if you're sure you want to turbo the Corolla:

The '98 does in fact use a deadhead (returnless) fuel system, so forget about using an FMU. You're going to want a higher capacity fuel pump, bigger injectors, and a good piggyback. I recommend Greddy eManage since you can control both fuel and timing with it. With the piggyback you can go a little higher on the boost, but you still have to be careful.

Oh, and don't *ever* use a thicker head gasket to reduce the compression ratio. Low compression pistons are the correct method of doing that.

Igor? damn dood are u from like Serbia or something?

actually the eclipse motor doesnt swap into the mirage, only the evo 4-6 motors do. and only a few parts swap over at all cuz a mirage is a 4g93, so unless you can get a 4g93T manifold from the JDM lancer turbo. The reason why i'm switching to the corolla is because my parents are complaining that the car's been in the driveway for a month, and they cant even move it cuz the tranny's dead.

but anyway, thanks for this info. i was already planning to use e-manage, mostly because of the timing adjustment feature. so how does this setup (returnless) adjust the fuel pressure throughout the RPM range? just by changing the voltage to the pump? or is pressure constant and the whole fuel setup controlled simply by varying the injector pulse width? what impedance are the corolla injectors btw?

The 4G63T will in fact swap into the Mirage with some work, it's not half bad actually. Reason I know is I had a Mirage and was thinking of doing that very swap.

But anyway, yes you're right on. The ECU varies the voltage to the pump and also compensates for the lack of (or excess of) pressure at certain points by changing the pulsewidth, for example when you stomp the throttle and the pump doesn't have time to take up the slack in pressure.

Not sure on the injectors in the '98...

you must have had a 4g mirage. the eclipse motors swap into that. the 5g's the engine is oriented the other way, so you need a evo engine to get a 4g63T

hahaha all DSM talk here lol

Actually he's talking about the Rolla. He said the Mitsi died.

we already figured that one out

so whats so bad about the returnless system? too much pressure drop across the injectors? or just hard to adjust fuel pressure? btw i read on turbosaturns.net that in their cars have a returnless and the pump always supplies the same pressure to the rail regardless of rpm. is this true in the corolla or is it like it was mentioned above with the varying of voltage based on rpm/etc thru the ECU? i wanted to call toyota and ask about it, but i thought i'd
give it a try here.

-Igor

The fuel rail for '98-'99 does have a regulator built into the rail (the shiny thingy in the middle of the rail between injectors), but not sure if it's regulated by a vacume line.

The fuel pump maintains constant pressure if the car is in ignition or running (based on Haynes).

hey well i have the emanage....and well DO I HAVE TO HAVE A RETURN FUEL LINE OR NOT?....HEY DOC WHICH DO YOU RECOMMEND?....AND WHY.

bump*

Nope, if you have the emanage then you should be okay. You do need larger injectors and keep an eye on things (fuel pressure) to see if you need a larger fuel pump (good idea either way).

-Doc

Just to let you know.. the item you are reffering to is a pulsation dampner not a regulator. It's there to reduce any resonance built up in the system.

I have only noticed a need when running super duty injectors on a returnless system. If you are planning on going balls out with your car you would want to convert to a return system with a larger volume fuel pump and rising rate fuel pressure regulator.

They have had supra's use the emanage and get past 20's I dont know if I would advise it... While the emanage is still good for boost over 20 psi you will most definatly want a J&S Unit to monitor knock at the high boost... you would also need to convert your system to a return system and a camcon would hurt to change your vvt timing!

Secondly at 20 psi you will max out the emanage capacity for larger injectors and will most likely have to use additional injectors...

You would need rods and pistons (dont need sleeves as our stock sleeves will hold up fine) Howeve ryou may want to balance and blueprint the block... The head doesnt need much done to it unless you plan to rev higher... however a P&P would open her up for all that extra airflow...

Then when you have done all this your car wont move since whenever you touch the gas itll just spin all over the place....

Honestly only a few cars get boosted to 20 psi and thats cuz without 20 psi they are dog slow!