alright all, im in the process of talking to someone about a trade for a turbo kit. my question is how safe/reliable for the engine is it to boost without any internal mods. as far as i know stock internals on the 420a can only handle 8psi right? so run at 8psi 2.5inch exhaust, tuned from first start up. how safe is it? or should i just wait and do it once my spare 420 is built? i'd appreciate any input. thanks

Originally posted by rustyrotors
alright all, im in the process of talking to someone about a trade for a turbo kit. my question is how safe/reliable for the engine is it to boost without any internal mods. as far as i know stock internals on the 420a can only handle 8psi right? so run at 8psi 2.5inch exhaust, tuned from first start up. how safe is it? or should i just wait and do it once my spare 420 is built? i'd appreciate any input. thanks

You should be fine. How many miles are on the car and have you done an compression test yet? if so what are those numbers?

The internals should be fine @ 8 psi, but it might be pushing it on the injectors. They are pretty close to being maxed out around 8 to 9 psi. I would never go any higher than 8 psi though, once you go past that then you have to worry about spinning a bearing. I boosted 10-12 psi on stock internals and spun a bearing in under a week. But, of course that was back when I was young and dumb.

its a 97 rs and im in the process of putting a used engine with 86,000. its from a mitsubishi dealership so its warranteed. so i know its in good shape. what do you recommend for fmu and fuel pump?

If you didn't want to go stand alone I would recommend a Vortech SFMU. Fuel pump I have a Walbro 255hp. Some people have had problems with Walbro; I havn't so far so I am sticking with it.

Originally posted by BoostedEclipse
The internals should be fine @ 8 psi, but it might be pushing it on the injectors. They are pretty close to being maxed out around 8 to 9 psi.

This too depends on the size of the turbo and how much it flows. Big difference between a T-25 and a 50 trim.

I can say my stock injectors were definetly maxing out with the star turbo at anything over 7psi.

Originally posted by rustyrotors
its a 97 rs and im in the process of putting a used engine with 86,000. its from a mitsubishi dealership so its warranteed. so i know its in good shape. what do you recommend for fmu and fuel pump?

I would keep in mind that they may not warranty the engine from failure if you boost it.

Originally posted by rustyrotors
what do you recommend for fmu and fuel pump?

If you're keeping stock injectors, the easiest/cheapest thing to do is use a 12:1 fmu and a walbro 255lph

its a 14b. star long route piping. and ya i know the dealership probably wouldnt cover the warranty for engine failure if i boosted. i just needed some opinions on whether its a good idea. and what the best way to go about it is. also what kind of hp gains am i looking at with a good tune? thanks

Originally posted by rustyrotors
i just needed some opinions on whether its a good idea.

I don't think it's a bad idea, especially if you're going to have a spare engine anyways. Even if something happens to the new one, you'll have something to replace it with. There are quite a few people on the board who have been boosted on stock internals for 1-2+ years, myself included (1.5 years for me)

Originally posted by rustyrotors
and what the best way to go about it is.

What's the best way to go about turbocharging the car?

Originally posted by rustyrotors
also what kind of hp gains am i looking at with a good tune? thanks

This is pretty much bench racing, and there's no real answer without you getting it together and dynoing it. People have seen between 180 and 220 though from running 8-10 psi, that's based from the dyno's I've seen for S16G's or turbonetics 50 trims. I haven't seen a dyno for a 14b on our cars. I would expect you to be on the lower end of that give or take some ponys

What are you planning on tuning with? If you want to be able to adjust fuel, then you are going to want to at least go the route of an sfmu. If you are planning on rebuilding the other engine with forged internals then you may want to look into either MSnS or the Portfueler

been boosting 6-8 for over 2years now on stock block

Try to stay away from the FMU and go to the SFMU. You want to be able to adjust you fuel and with the FMU you can't unless you change the disks and the injectors. Also, I would say that you should change the injectors that way they are not being over worked and you will have less chance of messing them up. So up the injectors and get the SFMU and you should be in good shape, plus it will set you up in the future if you want more power, cause you will.