We’ve been receiving a lot of questions about advice lately, and personally, we only like to give advice based on our own personal experience, not things we’ve heard or read ( especially on the internet ). So, we’ve decided to start the “Parts that Work” posts. This is where we post up parts we’ve used on our own cars, or installed on other people’s cars and genuinely tested. Doesn’t mean they aren’t the only things that work, but ones we can genuinely vouch for. So here goes.

NISMO POWERBRACE

First up, the Nismo Powerbrace for Silvias. Let me get straight to the point. This is one of, if not the most, effective suspension modification you can do to a Silvia and should be near the top of your list. The box section that joins the castor rods to the chassis is quote flimsy so the Nismo Powerbrace tightens up the front end. In a super low, super stiff car you might not notice as much as the stiffness hides most problems, but in our S14 with Tein Super Streets the difference in steering response and feel was fantastic. If you don’t have one. Buy one. Now! We got ours from Link International.

FULCRUM SUSPENSION TEIN SUPER STREET COILOVERS

Next, Fulcrum Suspension spec Tein Super Street Coilovers with EDFC. I’ve lost count of the amount of times I’ve heard someone say their super stiff Japanese spec coilvoers or Chinese knock-off coilovers are “pretty good on the street man!”  Bullshit. Clearly they have never driven on a decent set of coilovers. Spring rates of over 5kg in the front in a Silvia is simply too stiff for Australian roads, and quite frankly in my opinion, too stiff for tarmac rally, time attack and any type of mountain driving. Why? Not just because of ride comfort but because stiff coilovers don’t allow enough weight transfer. This has two problems:

1 – The front brakes lock up too easily or don’t work as well. Stiff coilovers stop the weight transferring onto the front wheels during breaking, causing them to lock up easily (as was the case in our S13 drift car) or cause them to not work as well (more the case with ABS equipped cars). Stiff suspension also causes the car to “pogo” over bumps, so on a mountain pass if there are bumps in the breaking area the car will unload and lock up easily. Think the end of the front straight at Queensland Raceway too.

2 – Silvia’s are relatively light and rear wheel drive so they need weight transfer over the rear wheels for grip. Not so much in a drift car, but in time attack, the extra body roll created by softer springs (which can be off-set by swawybars) is more than offset by the extra grip.

The Fulcrum Suspension “Aussie-spec” Tein Super Streets have 5kg/mm front springs and 4kg/mm rear springs. In the S14 they were perfect. Combined with the right wheel alignment the car could put down 330rwkW with ease through street tyres in a straight line and had excellent grip at the track on semis. And even better, they really did have a good ride on the road.

NISMO 1.5-way PRO-LSD TT-Model

An LSD is a very important part of the drivetrain. It helps put power down and contributes heavily to the handling behaviour. Factory viscous LSDs are terrible things, with drive only going to both wheels when wheel spin starts on one side, by which time it’s too late. They also wear out very quickly and often can’t decide weather they want to go single or double. Factory plated or mechanical LSDs are often too soft as well and usually worn out when enthusiasts grab hold of them. Locked diffs might be cheap and easy, and certainly guarantee equal drive to both wheels, they are rubbish to drive on the street, put strain on driveshafts and are illegal. I also personally dont like the way they drive in time attack or drift cars either with the transition from understeer to oversteer being too aggressive and un-predictable at times, but hey, some people love them and they have their place. 2-way differentials are great for drift cars, but can be too aggressive on back off (which helps a drift car) and un-settle a time attack car that might be trying to turn-in and brake at the same time. Many mechanical differentials are also quite aggressive on acceleration and can cause problems on tight corners. The Nismo 1.50-wy Pro-LSD TT-model solves all these problems, making it the perfect for time attack and/or the street.

 

A 1.5-way is less aggressive on back off than a 2-way and the TT-model of Nismo diffs has a less aggressive tooth profile so it engages smoother under load. When we put it in JET200 we were shocked how good it was. On the road driving normally, you didn’t even know there was a mechanical LSD in the car. Even tight u-turns on concrete would barely register a noise. Back off mid corner or turn-in under brakes were no problem and the car didn’t become un-settled, but give it full noise and the diff gave drive to both wheels every time. It was great in JET200 as a street car and now it’s great in JET200 as a time attack car. I wouldn’t use any other diff in a street or time attack car, and what do you know, a Nismo 2-way was in our drift car too!

TRUST SUMP

SR20 engines have terrible sumps from factory. One dent can block the pack-up and BANG! engine gone. I’d put a Trust enlarged and baffled sump on a Silvia before I’d do anything else. The extra liter of oil capacity helps with temperatures and the design stops oil surge. For some dumb reason I tried a different sump on JET200 and now it gets oil surge. Go figure. Forget big turbos and forged engines, a Trust sump should be on the top of the list, up there with exhaust and intercooler.

X-FORCE STAINLESS EXHAUST MANIFOLD SR20

For many years I’ve heard the argument between cast manifold vs stainless low mount manifold. Some say they make no power and just look good, others live by them. So, on our S13 drift car we put one to the test. Our Sr20 had 3-inch exhaust, intercooler, Nismo injectors, Haltech, boost controller and a GT2871R 0.64. It made 195rwkW on 18psi. We fitted a X-Force stainless manifold and power went to 225rwkW on 18psi. Enough said really. But every gain has a pain. The car lost some bottom end response, came on a bit later but it also revved harder and made more power everywhere above 5000rpm. It drove better and sounded better too!

NISMO SR20 740cc injectors

Straight drop in, factory driveability and flow enough for nearly 300rwKW. Super high quality as expected from Nismo. Enough said really

CONVERSION FROM HYDRAULIC TO SOLID LIFTER – HKS LASH KILLER KIT, FERREA DOUBLE VALVE SPRINGS and TOMEI PROCAMS

When I first built the engine in JEt200 i wanted to stay Hydraulic lifter for some odd reason, but after valve float, valve bind, struggling to rev over 8000rpm and a dropped valve, I decided stuff it, and went for solid lifters. Now, converting to solids seems simple, but it isn’t. It requires to be set up correctly to ensure a trouble free high-rpm life. I did some research before deciding which brands to go with and this is what I came up with. I noticed a couple of cars with the HKS head system were breaking rocker arms a lot so i looked deeper. You really have to use double valve springs as single valve springs bind at high lift. Some singles we tested binded  as early as 11.5mm lift (which caused the valve float and dropped valve we presume) while double valve springs can handle upwards of 13mm lift. Turns out each brand of double valve springs is a bit different. Some have high seat pressures, some low, some have high compressed pressure and some low. What you want is a high seat pressure to help ensure a good seal and quick closing, but, the least amount of compressed pressure to reduce the stress on the rocker arm. Turns out that Ferrea double valve springs were the best option  on paper ( don’t want o show and compare exact figures as others still work, and havn’t physically installed all types).

I also looked at lash killer kits and HKS were by far the best, why? Because you can adjust the clearance on the lifter side, meaning the shims on the fingers of the rocker arms stay factory  and you dont have to use test shims and get shims made. One shim per rocker arm instead of two makes them cheaper and easier to set-up and I also found that HKS lash killers out the rocker arms on a better angle.  Another benefit of solid lifers is that they dont compress under high power and the lift of the cam stays constant. WIth hydrualic lifters, oil pressue keeps them at the right clearance so when cylinder pressure pushes against them and RPMs get high, they can compress, reducing lift of the valve and reducing power with it.

When it came to choosing a solid type camshaft I went for Tomei 270 degree 12.5mm lift camshafts. We didn’t back to back them with another brand, but the car drove brilliantly and still does, so why change them. The minute we swapped from hydrualic to solid ( no other changes) the car went from having a 7800rpm powrband limit to a 8800rpm powerband limit and 9000rpm limiter!!! The first time I heard it on the dyno I cringed slightly! Jim from CRD simply laughed. Power went from 275rwkW on 19psi and 292rwkW on 23psi to 309rwkW on 19psi, 330rwkW on 22psi. Driveability improved due to the larger powerband and power was up everywhere.  Does this mean that an SR20 wont make power or work on hydraulics? Not necessarily, as I’ve seen other people’s set-ups work well, but no doubt, solid lifters would make their car perform even better.

 

I hope you enjoyed the read. Stay tuned for part 2

 

 

 

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