S14 Silvia, SR20DE to DET Conversion

[Feast Japan]

S14 Silvia, SR20DE to DET Conversion X2

Hey everyone, haven't been on the forum for some time now and best to share what ive been up to lately.

So the car originally was NA, had it making nearly 200PS with Toda 264 cams, intake, e-manage and other stuff. Went very well and took a lot of abuse at the track. Even went as brave as fitting 4.6 final drive. Best upgrade to date on a car that didnt have a lot of power.

I like to believe the car was pretty quick. Did a best of 1:12 at Ebisu circuits east course and a best of 2:19 on Fuji Speedways main course.

How it looked in NA config.

This past spring, I was up at Fuji running again and had some top end troubles pop up. Seems I either blew up the VCT sprocket and or over revved the motor and hurt one of the valves. Could have been repaired but at the same time a friend living at one of the air force bases had a complete kouki S14 K's he was trying to sell and even willing to sell the motor package.

I took his word on the condition and spec. Had Nismo 555's, Tomei 256 poncams, RAS's, Trust IC, Greddy oil cooler, Nismo coppermix clutch and HKS V-Pro for CPU.

We got the motor in over a weekend. Had a bit of wiring to re-pin to make the kouki harness work in my zenki, overall a breeze to do.

So in she sat, manual DIY boost con and all lol

Upon start up the motor had a terrible top end tick and hardly any oil pressure. We did have the motor tilted a little to much while cleaning up so we figured maybe a bit of air in the lifters. I also wanted to pull the bottom end apart to swap in an S15 oil pump I had sitting .

So the work began...

Did the oil pump from the bottom as didnt feel like pulling the head off. It apparently had a metal gasket but upon closer inspection it was just the stock unit.

As soon as the pan was removed I noticed all this debris. Ball bearings, other pieces of metal. This motor had a turbo failure at one point im thinking.

 

[Feast Japan]

With the bottom end apart I tackled the top end. Pulled out the old cams, rocker arm stopper and lifters and inspected all the parts.

Cams were in rough shape. Front bearing journals really warn out, obviously installed by an idiot. Two of the caps mid way back weren't even tightened down. Shaking my head at this point in anger!

Rather than fuss, I went ahead and bled out the lifters and re-installed. There was a bit of air in them, nothing out of the ordinary. But what really had me was the oil feed lines running on each cam bank. Sludged up, full of silicone and other ****. Both cleaned up so hopefully this will improve oiling to the top end.

With the motor all back together we fired it up. Alot of work and still no change. Top end rattled the same, oil presure still very low. Time to crack out the comp tester as we are close to write off stage.

Not looking good. This test was done with the motor warmed up correctly and WOT applied to all cylinders.

Now before you all think the friend I bought this from is a crook, think again. He manned up and promised to find a good working motor. Though I was in a rush and simply could not afford much more down time with the car so I went ahead and used one my regular parts suppliers here in Japan to source another one. This time from S15 Spec R, one with under 70K kM of use.

Collected and ready to go. All stock save for Nismo fuel reg adapter, HKS mani and outlet pipe.

 

[Feast Japan]

Had the old motor out pretty quick and prepped the S15 a little. Ended up swapping over the HKS turbo actuator and kept the factory 480CC injectors fitted.

Old junk coming out.

Friend is keeping it and maybe tear into it down the road. It rattled pretty bad, low comp and oil pressure but it went pretty fast on the factory T28. Some SR's I guess have strange ways before they really go out lol.

With the S15 motor fitted and running like a champ. Really good this motor and pleased to say it has great comp and oil pressure.

Bit of housing keeping on the mani, replacing injector insulator seals.

And routing Nismo FPR. Have it set at 3K as of now.

We managed to set up the V-Pro on 09/28 and still needs some more adjustments before I hit Fuji again.

Same night the car turned 78,000 KM....hahaahha

 

[Feast Japan]

On 09/29 I did a bit of shake down to feel out the new ECU map, take notes etc. I was just cruising out near the port when all of a sudden I lost all gears. It all happened so quick, I believed one of the main bearings in the gearbox let go. I was afterall still on the NA gearbox. And couldnt have been the clutch, it was an almost new Nismo Super Coppermix that came with that original junk DET engine.

So car collected and really low KM replacment box sorted out. And updated to SSR Type C in 17". 16" before were just too small for high power and trying to find a good tire was next to impossible.

We tackled the clutch this past Monday. With the oil drain plug removed the oil still showed clean. Not a good sign when you think the box is cooked. Rather than second guess we just pulled out the box and there it was, the clutch disc was in two pieces. Obviously a rivet failure and never seen this before. On backwards? Not a chance, it was set up correctly by myself.

So in a jam without a replacement Nismo disc. Luckily my good friend Dai that was helping with the swap had a line on an almost new ORC Carbon Pro clutch. No choice but to buy it.

Fitted and ready to put the replacement box in. No use keeping the NA box, im led to believe its still in good shape.

Driving back from Saitama to Yokohama was iffy, clutch needs to be bed in further as it wants to slip. I know carbon need to be heated up so ill take my time on this one. And the replacement DET gearbox is in fantastic shape.

TBC

 

[Murt]

Very nice write up! Hope the car holds with the new clutch.

 

[gaz_moose]

de and det boxes are the same

 

[Feast Japan]

de and det boxes are the same

Not entirely true. The NA has closer ratio and 3rd & 4th syncro's are under sizes compared to turbo box.

The NA box treated me pretty well and was only a little notchy going into third. Had to be really gentle on the circuit otherwise Id crunch going into 3rd.

 

[Feast Japan]

Map job went pretty well on 10/06. Only glitch was the standard 480CC injectors became maxed out while at 1.0~1.1kg/cm of boost. And this lead to a lean condition in the 6700-7000rpm range. The Nismo FPR was set at 3.0k already so I went ahead and turned up to 3.5k. Bit of more tweaking on the V-Pro and should be just fine this way.


Been using this Innovate A/F meter and a simple electric 52mm boost gauge.