[rett2kstang]

Alright, I was talking to a friend the other day and he told me that the n/a mkiv Supra has the same engine internals as the turbo, which I have a hard time believing. If this is true it seems like it would be a very simple matter to take an n/a car and add a turbo to it.

Is this info correct? How hard is the conversion?

Thanks for any info.

 

[DaveH]

First you need to add a 3mm headgasket to lower the compression ratio. The TT header is different, so you have to buy a na-t specific header. The oil pan needs to be drilled for oil return, and you need to tee into the oil supply line for the turbo. You have to hardwire in the VPC, and you'll need to use a resistor in your injector circuit, since the n/a uses high imp injectors. Otherwise upgrading the fuel system, and intercooler are the same as on the TT. You'll need custom intercooler pipes on the intake side. The n/a auto trans is weak and will need upgrading asap. The 5-speed is pretty tough, and just needs a good clutch for it to last a while. I just made 602rwhp on the stock n/a engine.

 

[Sleepr]

Dave made some good points, the block is essentially the same except for a few small details... HP capacity is nearly the same.
I'm not convinced that the low compression gasket is required if you're only after around 400rwhp. Custom build to order kits are available from Toyomoto in Miami FL and from Sound Performance. The kits will run around $6k, with another $1k in electronics and clutch. (Apexi AVC-R and S-AFC) The kit will have a T04E or T60-1 or similar mid to small sized turbo.

My SC300 layed down 423.4 Corrected RWHP on low boost (10-13psi) and pump gas on my setup. On race gas it will put out around 500rwhp maybe a little higher. All this on stock compression without pulling the engine, or going inside it for anything. Everything was basically bolt on, but pretty involved and took 70 hrs labor. Total investment will run around $7k to $8k for the power goodies, and you'll have to do all the work yourself at this price, but you'll be able to beat virtually any BPU Supra with this setup, and SPANK a 2002 Z06 on the freeway.

 

[rett2kstang]

What about using takeoffs from a TT Supra to keep costs down?

 

[greensoup]

I don't think you can swap engine parts between the two cars. You probably could use a stock side mount intercooler. Not the turbos.

Also Power House is reviving their NA turbo kit because of the IS300.

 

[Sleepr]

My kit had the side mount TT intercooler, stock TT bypass valve (ABV), MK3 T fuel pump, and various TT intake hoses, etc. The bulk of the expense is in the custom cast iron manifold and hard pipes- all of which takes a lot of labor as they're done one at a time. Some people say the Toyomoto exhaust manifold doesn't flow as well as headers, but many people have gotten 6XX and 7XX RWHP numbers with it, and thes side benefit is that it will never crack like headers do. Overall, I'd recommend Toyomoto for a quality kit that is maintenance free, and would probably go the same exact route, (larger turbo, perhaps).

 

[DaveH]

Hey Scott, are you using a timing retard box? like a
BTM? Just curious. Yeah, I guess you can get away without using the thick headgasket if you want to run lower hp levels. It probably helps your spoolup I'd guess also. But I wouldn't run much boost on pump gas.

The Toyomoto manifold is a nice piece, Jarrett had ported mine, and I'm sure it is good for lots of HP.

 

[Sleepr]

I've got an MSD 6BTM box, but its not hooked up yet. For now, I'm just backing off about 5 degrees on the dwell angle. I've found a better solution to timing retard, though. www.splitsec.com makes a timing controller that looks a lot more flexible...

As far as spoolup, I start making positive boost at 2000rpm with some lag, get around 6psi at 2500rpm and full boost by 3200rpm.

Now, about that porting... Any impressions on porting Toyomoto's manifold???? I'm extremely interested in details on what was done to it. Were the gains significant?

 

[DaveH]

That Split-Sec box looks really nice! The $550 price seems kinda steep though.

I wish my turbo spooled like that.

The manifold was ported when I got it. I know Jarrett matched the ports where it meets the cylinder head, but I'm not sure what else he did to it. It's long gone now.... it was stolen from the guy I sold it to.