SC400 single turbo project planning

[Mandrel]

Hey guys, I'm planning my next project and have been doing a little research for the build. I think I have the basics planned for a moderate build, so would like some feedback if I'm off base anywhere.

Here is what I am thinking so far:

'93 SC400 Auto

- Lower compression via head gaskets
- ARP head studs
- Possibly ARP rod bolts for stock/oem rods
- Upgrade valve springs to raise the rev limit
- BL or Titan built auto with ?? torque converter(Titan?)
- PTE Billet 67
- Tial BOV
- Tial wastegate
- Large FMIC
- Custom intercooler piping
- 3.5" downpipe/exhaust to twin 2.5"
- Custom T4 collector off stock manifolds
- AEM FI/C or AEM EMS(depends on if I need the EMS for the tranny)
- Bosch 044 fuel pump(would do a single Walbro 255, but I think I want more hp then one 255 can handle).
- Fuel injectors?? (haven't looked into sizing yet)

As far as power, what would you guys think this setup is capable of handling? I know what I want, but I'd like to hear what the general consensus is of what this simple motor prep/build will be able to take. Also, if you have any suggestions of other items or issues I should be considering, let me know.

 

[ruishy1]

tuned and setup properly i cant see why 500 bhp isnt achievable

 

[cribbj]

Lextreme also sells a built torque converter, and I think everyone who has bought one has been happy with it. Very good price as well.

If you're going to stay under 7000 RPM, you may not need to go into the short block at all, not even to change the rod & main bolts.

I would keep the upgraded valve springs, just to ensure the valves stay well sealed under boost.

I would have a valve job done while the heads are off, and of course, have the valve stem seals changed.

Also a new timing belt, tensioner, and idlers, and it wouldn't be a bad idea to get a new water pump, serp belt, idlers and tensioner.

A new oil pump with a new front seal would be a nice to have, but would require dropping the pans, etc. and you may not want to go this deep.

 

[Mandrel]

tuned and setup properly i cant see why 500 bhp isnt achievable

OK, that's what I expected the responses to be. I'm hoping to push the envelope a bit though.

Lextreme also sells a built torque converter, and I think everyone who has bought one has been happy with it. Very good price as well.

If you're going to stay under 7000 RPM, you may not need to go into the short block at all, not even to change the rod & main bolts.

I would keep the upgraded valve springs, just to ensure the valves stay well sealed under boost.

I would have a valve job done while the heads are off, and of course, have the valve stem seals changed.

Also a new timing belt, tensioner, and idlers, and it wouldn't be a bad idea to get a new water pump, serp belt, idlers and tensioner.

A new oil pump with a new front seal would be a nice to have, but would require dropping the pans, etc. and you may not want to go this deep.

Thanks for all the advice.

My first choice was/is the Lextreme TC. But I may be looking for more(if not right away.. down the road) then the "600hp" limit it seems they have on that TC?

I wouldn't be touching the main bolts, but from my experience with other platforms and builds like this, rod bolt just seam like a good idea. Maybe I'll skip them for the initial round of HP levels.

Was just planning on slapping the heads back on(to keep costs down), but I'll at least get them checked to see how they look to my machinist. I do like the idea of the changing the valve seals however. We'll see, gotta keep an eye on the budget a bit.

Timing belt etc. yup, planned on all that regardless, thanks for the heads up though.

Regarding the oil pump or front seal, do these cars/motors have issues with them? I didn't even have that on my radar, so if there is something I need to know, please let me know.

 

[JBrady]

I would definitely start with a stock 1st gen motor unopened. JustenGT8 made as much as (IIRC) 540rwhp which should be 600+flywheel on a bone stock engine and it lasted years running up to 25+psi at one point using an eaton SC plus twin turbos.

Start with the stock 10:1 engine, build your system, tune it, play with it, when you have it all working to your pleasure you can decide if the extra money to build more strength into the engine is needed and or worth it.

Of course the TUNE will determine if your stocker will last at these power levels but that would apply to even a built engine.

 

[Mandrel]

I would definitely start with a stock 1st gen motor unopened. JustenGT8 made as much as (IIRC) 540rwhp which should be 600+flywheel on a bone stock engine and it lasted years running up to 25+psi at one point using an eaton SC plus twin turbos.

Start with the stock 10:1 engine, build your system, tune it, play with it, when you have it all working to your pleasure you can decide if the extra money to build more strength into the engine is needed and or worth it.

Of course the TUNE will determine if your stocker will last at these power levels but that would apply to even a built engine.

That is great info. I'm happy to hear that the stock motor can/and has been proven to mid 500's. If that's the case, then I'll definitely leave it alone until I want 650whp or more.

After doing more reading, I'm thinking I'll also be looking for an LSD out of a auto Supra TT. Kinda surprised the SC's didn't come with LSD's from the factory.

I'm 50/50 right now if I'm going to go e85 on this car or leave it on pump gas/92 octane.

BTW, are there any threads about JustenGT8's car?

I have a tuner, just need to hammer down which option I'll be tuning with.

 

[stevechumo]

You can use thick MLS head gaskets to lower the compression, or you can machine off the heads' combustion area to lower the compression and use MLS standard thickness. Too thick of the head gaskets may throw off the timing a little bit. There's no need to touch the rods, but using ARP head studs is a good insurance.

As for an auto tranny, AEM EMS isn't very friendly to control it for daily driver. I think stock ECU controls the auto tranny best. You can stay with stock ECU and AEM F/IC to tune for the fuel/timing.

If you can pay BL or Titan for a rebuilt tranny, then it's the way to go. I'm very happy with Lextreme's torque converter, so I wouldn't pay $900 for other converter.

Supra TT Denso fuel pump is the best bet. I believe it flows 300 lph and it handles +500 rwhp easily. The nice thing is it can be installed in tank just like OEM pump with some minor modifications.

The RX-7 turbo (year of 88-89) fuel injectors will plug right into stock SC fuel rails and harness. They flow 460 cc/min and are good for more than 400 rwhp. I'm reaching 389 rwhp now and they seem working well. So if you want to upgrade the injectors, the easiest way is to go with either these OEM RX-7 injectors or upgraded RX-7 injectors.

Supra TT LSD will help big time with launching. More than 400 rwhp on this SC is getting hard to control on street tires. The brutal torque will steer the car off the line.

 

[Mandrel]

You can use thick MLS head gaskets to lower the compression, or you can machine off the heads' combustion area to lower the compression and use MLS standard thickness. Too thick of the head gaskets may throw off the timing a little bit. There's no need to touch the rods, but using ARP head studs is a good insurance.

As for an auto tranny, AEM EMS isn't very friendly to control it for daily driver. I think stock ECU controls the auto tranny best. You can stay with stock ECU and AEM F/IC to tune for the fuel/timing.

If you can pay BL or Titan for a rebuilt tranny, then it's the way to go. I'm very happy with Lextreme's torque converter, so I wouldn't pay $900 for other converter.

Supra TT Denso fuel pump is the best bet. I believe it flows 300 lph and it handles +500 rwhp easily. The nice thing is it can be installed in tank just like OEM pump with some minor modifications.

The RX-7 turbo (year of 88-89) fuel injectors will plug right into stock SC fuel rails and harness. They flow 460 cc/min and are good for more than 400 rwhp. I'm reaching 389 rwhp now and they seem working well. So if you want to upgrade the injectors, the easiest way is to go with either these OEM RX-7 injectors or upgraded RX-7 injectors.

Supra TT LSD will help big time with launching. More than 400 rwhp on this SC is getting hard to control on street tires. The brutal torque will steer the car off the line.

Thanks for the info. I'll probably stick with a MLS headgasket with the arp's when I am ready to touch the engine(including the rod bolts at that time).

Regarding the Lextreme TC, I don't think it will suit my HP needs/wants. I am looking for 500+ whp or bust, and 650whp or bust relatively soon after.

This will not be a daily driver, but I'm still up in the air if it will be EMS or FI/C. This likely will be a game time decision.

Tranny will be either a BL or Titan, no way around that.

Fuel system will be built and designed around supporting 650-700whp, so a Bosch 044 seems likely part of the mix.

The injector info is good stuff, didn't know they were drop-ins on these cars, that will help if/when I decide to run e85 and need very large injectors.

Yeah, from the looks of it, the LSD is a must, no way around it if I want to make use of the power I'm shooting for.

Thanks again for all your input.

 

[stevechumo]

That sounds like a nice major project. Keep us updated!

 

[SC400TT]

Thanks for the info. I'll probably stick with a MLS headgasket with the arp's when I am ready to touch the engine(including the rod bolts at that time).

Regarding the Lextreme TC, I don't think it will suit my HP needs/wants. I am looking for 500+ whp or bust, and 650whp or bust relatively soon after.

This will not be a daily driver, but I'm still up in the air if it will be EMS or FI/C. This likely will be a game time decision.

Tranny will be either a BL or Titan, no way around that.

Fuel system will be built and designed around supporting 650-700whp, so a Bosch 044 seems likely part of the mix.

The injector info is good stuff, didn't know they were drop-ins on these cars, that will help if/when I decide to run e85 and need very large injectors.

Yeah, from the looks of it, the LSD is a must, no way around it if I want to make use of the power I'm shooting for.

Thanks again for all your input.

There's a guy on CL selling a BL tranny for a hell of a deal. I believe it includes the Dragon TQ. I believe I saw around $1600 for the whole deal. The tranny is certifed in excellent shape from BL. You may want to jump on that deal...

GL on your project.

Ryan

 

[Lextreme II]

Stevechumo has a pretty successful setup. I have driven it and it screams.

 

[Mandrel]

That sounds like a nice major project. Keep us updated!

Once I have everything accumulated, I'll start a thread and post pics as I go.

There's a guy on CL selling a BL tranny for a hell of a deal. I believe it includes the Dragon TQ. I believe I saw around $1600 for the whole deal. The tranny is certifed in excellent shape from BL. You may want to jump on that deal...

GL on your project.

Ryan

I did a quick search(not the greatest at CL to be honest), but couldn't find that listing.

Regardless, I shouldn't spend that money right now. I'm likely going to sell the NSX, and take a little chunk of the proceeds to mod the car. So until that happens, I'll stick to the engine bay go fast parts, and leave the drivetrain alone until the other car sells(guessing sept - oct to be realistic).