1G GS to GST Upgrade

[royal_flush]

Hey guys, I'm relatively new to DSM and Eclipses, I recently bought a 94 Mitsubishi Eclipse GS as a project car to really get started into building a bit of a sleeper. My current prospect is looking into getting some boost added to the stock motor without having to get too deep into the internals. I'm not looking to get crazy with a 93mm turbo or whatever, but I'm trying to give it a some more kick than the stock 4cyl has got. I've read some similar builds that say with necessary upgrades, a 94 GS can safely make 10psi without having to touch the pistons. I'm not sure if that's accurate or not, but I'm still looking into what all I need to look at for installing a turbo. My current list of things to add/upgrade are:
- ECU upgraded to the turbo trim
- Install knock sensor
- Upgrade MAF (some guidance here would be much appreciated)
- Fuel injector/pump upgrades (injectors minimum 500cc)
- Intercooler addition
- Head gasket upgrade
- Oil pan upgraded to turbo trim
- Head bolts? (I'm told not necessary but highly recommended)
- Fuel pressure regulator
- Finally, the turbo itself (looking at a TR TD05 16g), BOV, necessary piping, and gauges, of course

So far that's the list I've compiled of things that I need to do to make sure nothing detonates . I'll also look into getting rid of the aftermarket exhaust the previous owner put on: I think it generates a little bit too much back pressure, but that's with stock internals, I have no idea how much I should look for on a boosted exhaust.

Any and all tips, recommendations, and advice would be much appreciated, thanks!

 

[Spleen8urLSX]

I did it, made over 400 at the wheels on the stock non turbo bottom end for 3 seasons and 20k street miles. Last time it was on the dyno it made 454 on pump gas on a 63mm Borg Warner, never got to go back and turn it up on e85 but had every intention of throwing 600ish at the stock non turbo bottom end. Unfortunately the seal on the oil filter let loose mid pull with my buddy’s wife’s Mustang. Even after all that pistons looked great, new engine going in is yet another stock non turbo bottom end 6 bolt. Best advice I can give is it’s all in the tune and the current health of the engine. I will say splurge for real engine management now if you can, on my first turbo set up running an Evo 3 16g, 560cc injectors, hacked 1g turbo maf, and an SAFC to tune with I had the car running real well and making 284 at 22psi on a heartbreaker Mustang dyno, the problem was the factory timing map was too aggressive on pump gas for the 9:1 compression non turbo pistons so I’d see knock on straight pump gas, had to mix a gallon of 110 octane race gas to every 4 gallons of 93 octane pump gas the rest of the season and it wouldn’t knock any. That was on a completely stock non turbo 6 bolt, stock cams, original head gasket and all.

Lastly, don’t believe the myths of “anything over 10psi will blow the engine!” or “anything over wastegate pressure from a stock 14b will crack the ring lands!”. Technology has come a long way since those threads originated 20 years ago. I’ve been through 4 different turbo set ups with mine now and will be running yet another non turbo block with a whole new turbo set up (I know I said I wasn’t gonna do it again for those following, but I lied!). Feel free to ask anything you want! I’m glad to see you’ve already done quite a bit of research on the topic so I’m always more than willing to help out.

 

[royal_flush]

I did it, made over 400 at the wheels on the stock non turbo bottom end for 3 seasons and 20k street miles. Last time it was on the dyno it made 454 on pump gas on a 63mm Borg Warner, never got to go back and turn it up on e85 but had every intention of throwing 600ish at the stock non turbo bottom end. Unfortunately the seal on the oil filter let loose mid pull with my buddy’s wife’s Mustang. Even after all that pistons looked great, new engine going in is yet another stock non turbo bottom end 6 bolt. Best advice I can give is it’s all in the tune and the current health of the engine. I will say splurge for real engine management now if you can, on my first turbo set up running an Evo 3 16g, 560cc injectors, hacked 1g turbo maf, and an SAFC to tune with I had the car running real well and making 284 at 22psi on a heartbreaker Mustang dyno, the problem was the factory timing map was too aggressive on pump gas for the 9:1 compression non turbo pistons so I’d see knock on straight pump gas, had to mix a gallon of 110 octane race gas to every 4 gallons of 93 octane pump gas the rest of the season and it wouldn’t knock any. That was on a completely stock non turbo 6 bolt, stock cams, original head gasket and all.

Lastly, don’t believe the myths of “anything over 10psi will blow the engine!” or “anything over wastegate pressure from a stock 14b will crack the ring lands!”. Technology has come a long way since those threads originated 20 years ago. I’ve been through 4 different turbo set ups with mine now and will be running yet another non turbo block with a whole new turbo set up (I know I said I wasn’t gonna do it again for those following, but I lied!). Feel free to ask anything you want! I’m glad to see you’ve already done quite a bit of research on the topic so I’m always more than willing to help out.

That's awesome, man!
The GS I bought has 115k on the odometer, so it's definitely a little older than yours when you started modifying. That's why I'm worried about some of the internals that can go giving boost. I'll be refreshing a lot of components to try to revive the engine health back to a much lower mileage (in spirit), but I'm worried about the head going on it, since it's an older block, gasket, and bolts. If I don't have to, I'd like to avoid redoing pistons, but if it's necessary, I'll definitely look into upping to forged pistons. I haven't gotten into it yet, but I know for sure I'm burning oil, so I'll definitely look into that, and I might have to get some new rings (which isn't a terrible idea for boosting it anyways...).

Sounds like the first turbo setup you ran is very similar to what I'm looking at putting in, so I'm hoping that means I'm on the right path here .

 

[Spleen8urLSX]

Mine had 110k on it when I put the first turbo set up on it and 130k on it when the great oil filter incident occured. After the first season I had no critical problems, however I still pulled the head over the winter and deep cleaned it and did a fresh Felpro composite head gasket and new valve seals and ARP head studs. After that is when I put it on ecmlink and 1450cc injectors and e85 and cranked it to the moon. It’s definitely not a bad move to pull the head and clean everything and re seal it, however none of the head internals will be susceptible to fail at what you’re looking to do. As far as the bottom end goes keep in mind the turbo pistons aren’t forged either, and internally the only difference is the pistons and lack of oil squirters, the block casting itself along with the crank and rods are that in the same as it’s factory turbo counterpart. My replacement has 156k on it, and as it runs strong I have no hesitation throwing power at it. Comes down to how far you plan to go with it really.

What I did is got my car running on a stock ecu and stock 450cc injectors with the stock matching components like the maf from a turbo car. Had a ported 2g exhaust manifold, no name tubular o2 housing (garbage, switched to a ported stock o2 housing the following season), 3” exhaust, Punishment racing (same kit that “cx racing” and “rev9” sell) front mount intercooler, just basic bolt ons pretty much that don’t require any tuning. That way I could assure it was running well in that form before I switched to the 560cc injectors and hacked maf with the safc installed and started turning up the boost. I did fine at 15psi, despite the age old rumors, the injectors were hitting 100% duty cycle at 5k rpm during wide open throttle and that’s the point I upgraded injectors. In short it’s good to have all the kinks worked out that way.

 

[19Eclipse90]

The moral of the story of the threads from 20 years ago is echoed in @Spleen8urLSX ’s post: without a method of tuning, beware!

Yes, both technology and general knowledge has improved. Back then, people were throwing turbos on N/T engines without a method of tuning or compensating somehow and upping the boost levels until something let go. Often, it was the piston ring lands. That is not a myth.

The purpose of the warnings and hesitations of “just sending it” are there for a reason. Just like in this case, the OP did not list any tuning solution in their list of parts. Had they not bothered to ask, the likelihood that they moved forward and it ultimately didn’t last long is pretty high.

With a proper tune, the possibilities are wide open (pun intended).

 

[Vegas Smith]

I'd skip the MAF and get a speed density setup for like $30. Car will run better and be less effected by air leaks.

 

[Spleen8urLSX]

The moral of the story of the threads from 20 years ago is echoed in @Spleen8urLSX ’s post: without a method of tuning, beware!

Yes, both technology and general knowledge has improved. Back then, people were throwing turbos on N/T engines without a method of tuning or compensating somehow and upping the boost levels until something let go. Often, it was the piston ring lands. That is not a myth.

The purpose of the warnings and hesitations of “just sending it” are there for a reason. Just like in this case, the OP did not list any tuning solution in their list of parts. Had they not bothered to ask, the likelihood that they moved forward and it ultimately didn’t last long is pretty high.

With a proper tune, the possibilities are wide open (pun intended).

Do keep in mind I mentioned using the stock turbo ecu in my comment and the limitations I found, however I should’ve been clear that I was monitoring with a data logger and of course a wideband gauge. I should have reiterated if not a method to tune at the least you SHOULD monitor with a logger to make sure it’s not seeing knock and things are working the way they should. You are right that is most definitely key there.