Boost capability

[Chunk182]

Hello all, I recently traded my truck and 500 dollars for 98 GS with 80k miles and in great shape (I got a steal, truck was a 97 dakota with 150k miles and a boat load of problems ). Ive been trolling around for the past week readin up as much as I can about 420a motors, turbos, and all the fun associated with them. Ive come to the conclusion that I would like to turbo the car despite the extra work necessary. After reading everything I still cannot figure out what kind of boost I can run in the car after I replace the pistons and rods with the JE pistons and eagles rods I have on order. Also, while I'm replacing the pistons, is it neceassy to replace the crankshaft or is the stock one capable of supporting 15psi? My long term goal for the car is 15~20psi. Thanks, and sorry for the long post.

 

[silverbullett]

Welcome to the forum.

Hahn Racecraft - Automotive Turbosystems

I've heard that this is one of the best kits out there for the 420a.

 

[turboAWDfanatic]

(I got a steal, truck was a 97 dakota with 150k miles and a boat load of problems ).

1) It's because of people like you that I hate buying used cars.
2) Remember, this *is* a public forum. The PO might read your post.
3) Sigh...welcome to the forums I guess.

 

[Chunk182]

1) It's because of people like you that I hate buying used cars.
2) Remember, this *is* a public forum. The PO might read your post.
3) Sigh...welcome to the forums I guess.

Hey now, he knew what he was getting into, that kid has far more wrench time than me, and if he is happy, which he is, Im happy.

Silverbullet, thanks for the welcome. Ive read alot about those kits, but Im more concerned with what internals I should replace, if any, while Im already in there putting the new pistons and rods in to hit my target PSI for a dd. I figure I should take it slow and make sure I have an engine thats worthy of forced induction before It actually gets a taste of turbo.

 

[Hollywood77]

Hey now, he knew what he was getting into, that kid has far more wrench time than me, and if he is happy, which he is, Im happy.

Silverbullet, thanks for the welcome. Ive read alot about those kits, but Im more concerned with what internals I should replace, if any, while Im already in there putting the new pistons and rods in to hit my target PSI for a dd. I figure I should take it slow and make sure I have an engine thats worthy of forced induction before It actually gets a taste of turbo.

You've definitely got your head on straight. You're doin' it right. Build that engine to handle the turbo that you'll end up bolting on. A lot of peeps get the cart in front of the horse and end up spending their $$ on a big turbo, and then wondering why they're havin' engine problems.

Kudos to you!!

 

[Locke]

After you replace the bottom end, fuel and tuning are the only things holding you back. With proper fuelling, JE's and Eagle's will handle 20psi easily.

There are no known issues with the 420a's factory crankshaft. It'll handle the power fine.

 

[99RedGs]

I would upgrade/replace:

Pistons
Rods
Main Bearings
Oil Pump (Melling possibly high flow)
Rod Bearings
Head studs
Main studs

Whatever your final goals end up being will determine your fuel needs.

Im sure you know what you would want for each of those, but when I spend the money to build a motor I like to over build so I don't need to worry about more issues. The stock head has been proven to over 500 hp so A stock rebuild would be sufficient, but depending on your goals in the end you may choose a different route. By replacing the Rods/Pistons you are pretty much removing the weak link in the 420a in terms of boost. It is a strong engine and can take pretty much whatever you can throw at it (Power Wise). I guess the other weak link would be our choice of tuning OPTIONS, but we have MS and that is good.

Good luck on your build.

 

[Chunk182]

Thanks for the advice everyone, Im going 420a hunting tommorrow so I can rip it appart and have it ready for when the pistons and rods arrive. Ill do my best to keep everyone posted on how it goes. It should be interesting since Ive never done anything like this before, but Ill have some help talking me threw.

 

[cs82685]

After you replace the bottom end, fuel and tuning are the only things holding you back. With proper fuelling, JE's and Eagle's will handle 20psi easily.

There are no known issues with the 420a's factory crankshaft. It'll handle the power fine.

^What he said. If you're going out of the gate with a built bottom end, then all you need to do is have the fuel and tuning capabilities to support the boost you want. Keep in mind though when you're making big power, you're going to run into issues with other items failing also. (i.e. look into some drivetrain mods perhaps, at least put in a beefier clutch while you have the motor out)

 

[turboAWDfanatic]

Hey now, he knew what he was getting into, that kid has far more wrench time than me, and if he is happy, which he is, Im happy.

Whoops, my bad. I mis-read your original post. I thought you were coming in here to brag that you ripped off some guy w/o him knowing. Sorry bout that!

 

[BenHooker]

If not already installed, a cat back would also be a necessity for when you have your turbo put in to handle the power your puttin out, especially if your aimin for 15+ PSI

 

[98GSXtreme07]

Don't forget about the transmission as well! That thing will be taking a beating at 15 psi. Glad your going the right/smart way with building up your motor first before it see's boost.

 

[1996dsm]

good luck with the build. im doing the same thing, i got an extra motor ive been working on for a short while. dont want to slap a turbo on and blow a decent stock motor.

 

[Blackndropped]

Same thing for me...Got another bloc sitting in my garage for the cold winter days...gonna build this bottom end and put my completly modified head on top of it!!!

While I'm here...
I'm surely gonna put some ARP headstud, but should I go with other ARP studs or bolts somewhere in the engine building????
And for the injectors, can I just put some 450cc dsm injectors ou should I go bigger??? (oh yeah I'm gonna run a s-fmu, no MS for now)

 

[dr1665]

Do yourself a favor and stop dropping PSI like it means jack sh*t by itself. You know when you build a car for "20psi?" When your car came with a turbo and you're building things up to support 20psi on the OE turbo. Otherwise, you're lumping yourself in with all those numbskull sycophants on the web who don't really know what they're talking about.

Basing your entire project upon a random boost pressure you want to run is f*cking stupid. HOLD ON. I'M NOT SAYING YOU'RE STUPID. KEEP READING WITH AN OPEN MIND.

Consider, instead, basing your entire project on something like 400hp. Before you say, "Well 400hp isn't much," grab a piece of paper and write down the names of all the 2GNT DSMers you know of who are making 400whp. If you know of SIX such people, then they put something special in the water over there. Besides, 400whp is nothing to sneeze at. I'm going to use 400 as the basis of this post.

The point is, if you set yourself a goal of making 400whp, this allows you to select the best turbo to get there. Why would you spend all that money for a GT42 that's capable of 800hp or something crazy like that, when you're aiming for 400? Sure, we all want to drive 800hp Konigsegg fighters, but keep your goals realistic. If this car will spend more time in traffic than at the track, wouldn't you happily trade ultimate redline power for awesome response down low?

When you have an intelligent goal set for the car like 400hp, not only can you select the best turbo for the project - one which flows the CFM needed to achieve 400, maybe slightly more horsepower - you can select the requisite fuel system components to meet that goal. Then you have a car which, on paper, will get you where you want to be. Technically, since you've done your homework, you know you have a 400hp 2GNT right out of the box. All you have to do is tune the old girl and you're there!

So you start out on the smaller end of the spectrum. You put a minimum of boost through the mill and you make sure the car has a good, solid tune. It is imperative that you are able to recognize the car running AS IT SHOULD. Do not settle for sloppy tuning. You will lose your f*cking ass on this investment. This is all money you will never, 100% get back. Your $2000 GS is not worth $6000 just because you put $4000 into it. It's a fact of life.

Why mention that nonsense? Because it goes to show that you want to take the best possible care of your investment now. Get the car running like a champenis right out of the box on low boost where it is easier to tune. Become one with your engine. Methodically bring up the boost pressure while increasing injector pulsewidth. Keep a close eye on your (wideband) AFR and maybe EGTs too. With each step you take, keep that car running like a goddamned top. If you've been true to your goal, you will have *almost* maxed out your turbo, *almost* maxed out your fuel system, and have a PERFECTLY RELIABLE 400HP STREET CAR at your disposal. (Not to mention the brains and balls to swap out that turbo and injectors to go even farther if you ever get bored with it.)

If you take the time to evaluate where you will have the most fun with this car and come up with a solid goal for PEAK OUTPUT, that goal will make it easier, MUCH EASIER for you to properly select your bits and do it up right the first time. If you're building for some random PSI figure like some random, internet knucklehead, who knows what you'll get?

Turbos are tools which get you to your horsepower goals. Don't aim for PSI. Aim for POWER.

PS - Your NV-T350 transmission is solid. Don't worry about it beyond changing the fluid, perhaps installing an LSD, and safing brackets on the diff. Axles may break, but careful launching can prevent that, and there's no point in spending money on things you don't really need. The most important transmission-related consideration you have on a highly boosted, mostly street-driven 2GNT is the clutch. Of course, if you know you've got a 400hp target, you can call up SBC and tell them about how you're getting there and let them build the perfect clutch for you.

Don't you just love how a proper goal makes decisions easier?

 

[Chunk182]

My whole goal has been 350-400hp, I guess Ive failed to bring that up, but that wasnt so much of the point of my post. I guess I was curious as to what stock parts would be reliable through my build and which wouldnt. Im sure you think Im just another tard with lofty boost goals, and I suppose thats fine if youd like to see it that way, but In my defense, Im learning the ropes quite abit ahead of the curve. But Im also doing my build on a budget, I have 2 Gs to purchase a blown but solid engine and all the fun stuff after. Maybe 2 Gs is enough, maybe its not, but I know what I have, where Im at, and where Id like to be. Im setting some goals and trying to get as close as possible, you cant fault a guy for that right?

 

[Slippi84]

Do yourself a favor and stop dropping PSI like it means jack sh*t by itself. You know when you build a car for "20psi?" When your car came with a turbo and you're building things up to support 20psi on the OE turbo. Otherwise, you're lumping yourself in with all those numbskull sycophants on the web who don't really know what they're talking about.

Basing your entire project upon a random boost pressure you want to run is f*cking stupid. HOLD ON. I'M NOT SAYING YOU'RE STUPID. KEEP READING WITH AN OPEN MIND.

Consider, instead, basing your entire project on something like 400hp. Before you say, "Well 400hp isn't much," grab a piece of paper and write down the names of all the 2GNT DSMers you know of who are making 400whp. If you know of SIX such people, then they put something special in the water over there. Besides, 400whp is nothing to sneeze at. I'm going to use 400 as the basis of this post.

The point is, if you set yourself a goal of making 400whp, this allows you to select the best turbo to get there. Why would you spend all that money for a GT42 that's capable of 800hp or something crazy like that, when you're aiming for 400? Sure, we all want to drive 800hp Konigsegg fighters, but keep your goals realistic. If this car will spend more time in traffic than at the track, wouldn't you happily trade ultimate redline power for awesome response down low?

When you have an intelligent goal set for the car like 400hp, not only can you select the best turbo for the project - one which flows the CFM needed to achieve 400, maybe slightly more horsepower - you can select the requisite fuel system components to meet that goal. Then you have a car which, on paper, will get you where you want to be. Technically, since you've done your homework, you know you have a 400hp 2GNT right out of the box. All you have to do is tune the old girl and you're there!

So you start out on the smaller end of the spectrum. You put a minimum of boost through the mill and you make sure the car has a good, solid tune. It is imperative that you are able to recognize the car running AS IT SHOULD. Do not settle for sloppy tuning. You will lose your f*cking ass on this investment. This is all money you will never, 100% get back. Your $2000 GS is not worth $6000 just because you put $4000 into it. It's a fact of life.

Why mention that nonsense? Because it goes to show that you want to take the best possible care of your investment now. Get the car running like a champenis right out of the box on low boost where it is easier to tune. Become one with your engine. Methodically bring up the boost pressure while increasing injector pulsewidth. Keep a close eye on your (wideband) AFR and maybe EGTs too. With each step you take, keep that car running like a goddamned top. If you've been true to your goal, you will have *almost* maxed out your turbo, *almost* maxed out your fuel system, and have a PERFECTLY RELIABLE 400HP STREET CAR at your disposal. (Not to mention the brains and balls to swap out that turbo and injectors to go even farther if you ever get bored with it.)

If you take the time to evaluate where you will have the most fun with this car and come up with a solid goal for PEAK OUTPUT, that goal will make it easier, MUCH EASIER for you to properly select your bits and do it up right the first time. If you're building for some random PSI figure like some random, internet knucklehead, who knows what you'll get?

Turbos are tools which get you to your horsepower goals. Don't aim for PSI. Aim for POWER.

PS - Your NV-T350 transmission is solid. Don't worry about it beyond changing the fluid, perhaps installing an LSD, and safing brackets on the diff. Axles may break, but careful launching can prevent that, and there's no point in spending money on things you don't really need. The most important transmission-related consideration you have on a highly boosted, mostly street-driven 2GNT is the clutch. Of course, if you know you've got a 400hp target, you can call up SBC and tell them about how you're getting there and let them build the perfect clutch for you.

Don't you just love how a proper goal makes decisions easier?

Someone started pregaming for the 4th a little early . Everything he said is right though. May have come across like mel Gibson in conspiracy theory but still right. Forget the hahn kits. If you just put a little more research in you will get more for your money and have a better car if you piece a kit together. You just have to know what to look for. As far as internals at most you might want to get the crank treated but hahn made 600hp on the stock crank so I think you'll be fine. Not to mention I have never heard of one going because of power yet.

 

[bagged420a]

Someone started pregaming for the 4th a little early . Everything he said is right though. May have come across like mel Gibson in conspiracy theory but still right. Forget the hahn kits. If you just put a little more research in you will get more for your money and have a better car if you piece a kit together. You just have to know what to look for. As far as internals at most you might want to get the crank treated but hahn made 600hp on the stock crank so I think you'll be fine. Not to mention I have never heard of one going because of power yet.

I agree with him I went with the hahn stage II kit. and 2 years later and wanting more hp I'm finding out what i should have bought in the first place, and probably could have saved a few hundred bucks and a lot of wrench time.