What Turbo Kit is Best for 420A 99' NT

[Drift_Kit_Laser]

I currently have a 99 NT with the 420A motor... Im in the process of having a rebuild kit put into the motor.. Once that is installed and the car is up and running nice and strong I plan to turbo the car. But Im wandering which kits are the best overall for HP/TRQ and for overall quality. So if you know off hand which kits are better than others either from experience or from the grape vine let me know. Thanks

Cpl Thompson JT
USMC

 

[Boost92awd]

Hahn Racecraft, is probally the best out there for N/T DSM's. But alittle on the expensive side. If money is alittle tight I would look into peiceing a kit together, its cheaper to do it that way.

 

[Drift_Kit_Laser]

If I were to piece together my own set-up. should i go with factory size turbo or could i go a little larger even though im throwin it onto a previously NA motor?

 

[Boost92awd]

If I were to piece together my own set-up. should i go with factory size turbo or could i go a little larger even though im throwin it onto a previously NA motor?

I would just run a 14b (stock 1G turbo). There cheap and there alot of them out there. It would make much since to go any bigger with a stock N/A motor. Plus the 14B is capable of over 300 WHP.

 

[silver bullit]

USMC, treating you good?

I would advise you piece together a turbo kit, cheaper, if done correctly will result in the same outcome with less money. While you piece this together you can break the 420a in NA then run turbo.

 

[JusMX141]

Message - DSM Classifieds

 

[Noogabox]

hahn racecraft is the way

I already have a Hahn racecraft system and I am about to upgrade to a Stage 2 system from them, However I am concerned about fine tune ability, any ideas? I already have a APEXI SAFC2 should I use it?

 

[99RedGs]

I currently have a 99 NT with the 420A motor... Im in the process of having a rebuild kit put into the motor.. Once that is installed and the car is up and running nice and strong I plan to turbo the car. But Im wandering which kits are the best overall for HP/TRQ and for overall quality. So if you know off hand which kits are better than others either from experience or from the grape vine let me know. Thanks

Cpl Thompson JT
USMC

Are you just rebuilding the motor, or are you upgrading internals? If you aren't upgrading internals you will be able to push somewhere around 8 psi or so, so I would just get a factory size turbo like the 14b or something. There is no need for a bigger turbo if you can't boost past 8psi.

Im in the process of upgrading a motor, and although it would be much easier to buy a kit, I am just going to piece on together because it seems more cost effective. You should be able to find everything you will need in a thread on here or by looking at what a kit comes with. Then just keep an eye on the classifieds and LOCAL craigslist.

 

[Drift_Kit_Laser]

I planned on just rebuilding the engine with the factory components, but.. Does anyone know of a rebuild kit that has upgraded internals? Or will i just have to piece together a complete upgraded kit myself?

 

[95TalonOwner]

I already have a Hahn racecraft system and I am about to upgrade to a Stage 2 system from them, However I am concerned about fine tune ability, any ideas? I already have a APEXI SAFC2 should I use it?

Don't use the SAFC. It won't do you and good since our cars weren't meant to be turbo so you'd only be able to control the fuel curve in vacuum up to 0 psi.

 

[99RedGs]

Here is the deal (atleast how I look at it)

You are going to be rebuilding this motor OEM and adding a turbo kit. You can only boost easily around 8, and with good fuel tuning from 10-12. I don't know if you have ever experienced boost before or not, but when you do I can almost guarantee you will keep wanting more. When that times comes you will have to rebuild the motor forged. So why not skip the OEM build and go straight to forged. You are already spending the money on the turbo why not get the most of it? There are upgraded bottom end kits at howell ( 2.0 Performance Bottom end Kit - bottomendkit ). The stock top end on the 420A has been up to 500hp I believe so I would just inspect it and replace anything worn, and just avoid a top end kit. You can probably piece together a kit easily and it may be cheaper but it also may just be worth the price for the convenience.

Check out the supporting vendors for the site as a few of them will also have kits like the one I posted.

**On a side note- If you order from Howell you may have to wait a while as I hear they take a while to ship things. No experience with them so it is just hearsay from reading, but just a heads up.**

 

[Maurice_RS-T]

The howell kits are good, but I did have to wait for mine for about 4 months.

 

[Locke]

I'm not aware of the 420a factory bottom end ever holding to 500hp, rather around 300hp with good tuning. Post a link if I am wrong.

The 420a's factory Mahle pistons are excellent at what they were intended for, ~150 NA bhp, but they were never intended to see boost. The ring lands will lift with excessive power or inadequate tuning. JE and Wiseco pistons have much heavier ring lands, and are more robust than the factory Mahle's. Coupled with Eagle rods, this makes for a very tough and relatively inexpensive bottom end. I wouldn't trust a Top-Line reciprocating assembly (if you considered these for your rebuild) to handle as much crap as the OE pieces.


To conclude, do it right the first time. You'll thank yourself later.

 

[Drift_Kit_Laser]

so what im gathering from what everyone is sayin..is the main thing i would need to get more than 8psi would be to install forged pistons... if i was to get a basic oem rebuild kit, could i replace those pistons with forged pistons? or is there a difference?

 

[99RedGs]

I'm not aware of the 420a factory bottom end ever holding to 500hp, rather around 300hp with good tuning. Post a link if I am wrong.

If the first question was for my post I said, "The stock top end on the 420A has been up to 500hp." Hahns car.

First you should have your block cleaned up and honed and checked out. If it needs to be bored out so it has fresh walls then go with .020 over. Once that is taken care of then order your pistons and rings that are the correct size for your bore. Basically if you order standard bore pistons, but you need to overbore the cylinder for whatever reason you will have to re-order the proper piston size.

Second, If you get the OEM rebuild kit and replace the pistons and rods with forged ones you should be fine. What you need to check though is that the bearing and everything will fit with the new rods.

Also if you are going to spend the money on the forged pistons, then buy forged rods with them. The motor is as strong as its weakest link. So if you have 500hp rated pistons and 200hp rated rods there is no reason to have the 500hp rated pistons because the rods will break anyways. Eagle rods and Wiseco pistons seem to be the popular combo, but there are plenty of other brands out there.

 

[95TalonOwner]

Also, if you are planning on going turbo. Remember to order lower compression pistons. Normal lower ones are 8.6:1.

 

[Noogabox]

Don't use the SAFC. It won't do you and good since our cars weren't meant to be turbo so you'd only be able to control the fuel curve in vacuum up to 0 psi.

I have a Boost sensor from Motorola that I can use that reads up to 5 volts. So I will use that instead of my stock Map Signal. This way the Apexi can use the Boost Curve to tune as well. Yay I cheated the system, Im stickin it to the man Yo! What I am trying to say is I want to tune like 4g63 owners can . I already found the schematic wiring diagram and I will do a Write up on the install when its done this weekend I think!

Codename: Upgrade, Xbox 360 Talon Write up for the Boost sensor mod will be posted here ( note that the Stock ECU will still only see vacuum and the SAFC sees boost)

 

[Locke]

If the first question was for my post I said, "The stock top end on the 420A has been up to 500hp." Hahns car.

Right you are. My bad.

I have a Boost sensor from Motorola that I can use that reads up to 5 volts. So I will use that instead of my stock Map Signal. This way the Apexi can use the Boost Curve to tune as well. Yay I cheated the system, Im stickin it to the man Yo! What I am trying to say is I want to tune like 4g63 owners can . I already found the schematic wiring diagram and I will do a Write up on the install when its done this weekend I think!

Your plan is flawed.

The OE MAP sensor will read boost, that is not the problem. The problem is that when the ECU sees a signal indicative of boost it will cut fuel. The only solution to this, while maintaining the factory ECU for fuel control, is to prevent the ECU from seeing the signal while in boost. The ML prevents the MAP sensor from seeing boost, and the FCD prevents the boost signal from the MAP (sans ML) from reaching the ECU. This is where the problem with SAFC tuning a boosted 2gnt comes in. Because the ECU is only seeing a signal up to 0psi, a SAFC will only work under 0psi. You can adjust the signal all you want for positive pressures, but the ECU will never see the signal so the ECU will not supply more fuel that would be at 0psi.

An SAFC will function as designed for tuning fuel while in vacuum, but it won't do anything while in boost on a 420a with a FCD/ML in place, regardless of what sensors you use.



There is some trickery Corbin did using the TPS with an SAFC to enable him to sort-of tune in boost, but this method is not recommended and barely worth it. Information on this is stored at 2gnt.com.

 

[ashram]

If you can still find it I would go with the star turbo kit, I had it on my 96 rs before i sold her. The kit comes with a turbonetics t3't4. I had the stage one kit which came non intercooled. I was only pushing five pounds of boost but it really woke my car up. i bought it from importparts.com

 

[johnsonroda27]

easiest nice way .. hahns kit is very nice

 

[sadc]

all i say is good luck

 

[Noogabox]

An SAFC will function as designed for tuning fuel while in vacuum, but it won't do anything while in boost on a 420a with a FCD/ML in place, regardless of what sensors you use.

I think you missed the point, Of course the OEM Map cant see boost due to the Electronic Fuel cut defender. The idea is to use a seperate Pressure sensor wired to the TPS input on the APEXI. The pressure sensor does not interfere with the Map sensor voltage. only the Apexi adjusts it. The you then adjust the APexi based off signal from the boost sensor instead of the TPS. However even though this makes the APEXI work I have found that it only react once the boost is there. So reaction is slugish and wants to bogg if you stomp the gas. So I removed it but it was an interesting thing to do. I went off Corbins instructions. I am staying with the FMU and slightly larger injectors since it works great as it is.