Re: Nissan SR20 tech Info, Know Hows, FAQs

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Re: Nissan SR20 tech Info, Know Hows, FAQs

Post by kiwiturbo7 » Fri Nov 05, 2010 12:02 am

I now have my 7 replica running with an S13 SR20DET and Link ecu in it. Not pretty yet and still needs to be tuned and certified for the conversion. Chassis is a faithful 7 replica so its a very tight fit. Had to widen the tunnel for the 5sp. I am running a R200 Nissan Viscous LSD with Jap R31 Skyline half shafts (unmodified they just make it). I had to mix and match the cv joints with the newer R32/ Sylvia/ Cefiro ones to get the 3 x 2 bolt pattern of my diff. I rebuilt the rear as a de-dion using Cefiro/Skyline uprights. Rear calipers are from R30 Aussie skyline (live axle model). They are not well loved by many but were the only ones I found with a suitable piston size to give a theoretically balanced braking set up. They are nice and light and mostly alli. R200 LSD Diffs are a bargain at under $60 from Pick a Part but they excessively heavy at 37kg. If doing again I would look at getting a complete Nissan GTIR rear and adapting that. Much lighter and LSD. You will need a deep 19mm socket and a big bar for the 2 rear bolts if you get a newer R200. Look for the diffs in the Serena vans as many of them are LSD but have ratios up to 4.6 and even seen a 4.9. Most are 4.4. I am looking to change mine for a 3.6 or 3.9 to try and dumb down the ridiculous wheel spin I'm getting.
I used the DE inlet (same pipe sizes) to place the intake and intercooler at the rear of the engine bay. I have shielded this area from the engine bay and feed it air with an old Toyota Levin Supercharger scoop. This means the radiator is free to do its job without heat and or restriction from an IC being up front. I also ducted the radiator air out the top of the nose cone to hopefully reduce engine bay temp issues (working so far but no track use yet). I had to use an after market Redline but watch for distorted flanges) exhaust manifold that had the right shaped no.1 pipe to give room for the turbo compressor outlet to head up and over the top of the turbo and back to the intercooler - very tight. The alternator is replaced and moved to the other side to make room for the steering column and remote oil filter/ cooler pipe work. I used a Starlet alternator - much smaller.
The turbo is the "Disco Potato" Garrett GT28RS. A this early stage I can not get the boost below 15psi and would like to do so while I get used to wheel spin coming on at 1/2 throttle 3rd gear straight line in the dry. Even did an unrelenting wheelie down our long drive with a 3rd gear take off! Tyres at the moment are 225/50/16 Eagle F1s but have semi slicks waiting to fit.
If you find an old R30 Skyline then grab the front hubs as they fit Ford uprights and give you the 114mm stud pattern. RWD Bluebirds will also work. Use Honda Legend 4 stud 280mm top hat style rotors and make mounts to suit your choice of caliper.
Sorry, I have digressed from SR20s.
I had to split my Lotus copy nose cone and insert 50mm into it. I made the split in the most vertical part of the sides and ran it down under the front opening so as to keep the opening looking standard. The 50mm is hidden behind the number plate. The bonnet still sits on the standard scuttle. I tidied the lower bonnet edge with a parallel vented piece of alli. Clearance to the rocker cover is almost zero in an attempt to get sump to ground clearance. Ended up with about 75mm. I now have a dry sump set up to install that will give heaps of clearance but I'm mainly installing it to stop oil surge. I've seen too many mysteriously run bearings on 7 style cars.
If you trip over a Pulsar GTIR motor/head like I tried to use originally then beware of some of these non compatible bits with all other SRs. Inlet manifold is no go on SR heads so cant use those quad throttle bodies. They also stick up higher than the rocker cover and would require a big hole in the bonnet if you end up fitting the hole head. The flywheel bolt pattern is different and also the bell-housing pattern.
Hmmm - what else SR related... Oh yea, "rocker stoppers" are recommended. A friend stuffed his head with a missed gear change, peaked revs and rockers falling out or what ever they do.
There is a trick with the injectors where you remove (file off) the fine 4 holed screen that covers the pintal. This can increase flow by 50% on Bluebird ones (making them flow more than DET ones) and spray pattern is still OK.
I stuffed my SRDET igniter pack with a wrong setting on the Link. They are expensive so I used 4 x Bluebird/Primera ones sandwiched between alloy plates (for cooling). It means I have one igniter for each spark-plug coil pack and if one packs up it will run on 3 cylinders and can be easily found.
Cams - SRDE inlet cams are a slightly hotter profile than SRDET ones. Lift is 248 instead of 240 and duration 10 instead of 9.2 could be worth messing with?
Years ago I spoke with Reg Cooke (Nissan guru) He said that the heat problem we typically have in turbo sevens would be better if the boost was kept low and get the power gains using hotter cams. I need to get that boost down first using a standard actuator instead of the one that came with the turbo.
Enough for now - Cheers John

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