RB25DET's ran 9:1 comp and were built back in the 90's, hell my dads one ran 24PSI before he sold it. People regularly boost S2000's that run 11:1+ static compression on stock blocks and they seem to run fine, why wouldn't a zed? Too many people adding a bit too much "theory" when it doesn't quite work the way they think in real life. Add some water/meth, run 1 bar of boost and have fun is all i can say!
I run a SR20DE+T as a daily, ran it on 12 psi for 6 months but got sick of having to keep an eye on the boost gauge( 12psi under full load in 3rd, but past 16 full load 5th) Since then I just run gate pressure and its a solid 9 so my gauge says but i know its more like 7.. Sure it has more go off the line than any sr20det but after about 3500 rpm they have you hands down, you just cant compete with more boost. Add higher intake/engine temps (90C+ all day) and the fact that i have a crapload of fuel in the mix to cool the pistons. And my tiny IC and lack of water injection. I got 12 months out of an unopened sr20de on 12 psi, second engine with almost another 12 on it and with constant abuse running gate pressure it hasnt really skipped a beat. Compression tests are all within spec. If i had to do it again id just go low comp for the simplicity. One thing thats always made me raise an eyebrow towards the VG30DETT vs VG30DE is the fact that they both have the same plenum???
static comp doesnt mean shit when you have cams that size. thats why they are running 11to1, on the big lobes, that would be way less Im a fan of low comp simple turbo builds for less complexity , cost, ease of tuning. I build my stuff to drive on the street, run pump fuel and have it perform the same day in and day out. I think turbo lag is overstated, on my rb20 i get adecent amount of lag, but only once, then every gear after that its on song. and if i launch it dont even get lag once. My opinion is people are obsessed with e85 , high comp, water meth blah blah , all for big dyno figures and internet points. Technology and tuning has come along way but basic reliable pump fuel turbo motors still have a place .
Off the top of my head I think boost solenoids are the only thing a TT engine has that NA doesn't in terms of connectors so unless you want to use those you'll be fine. Just make sure its in good condition. Expect your car to be off the road for a while, took me about three months with all the other things I ended up having to sort out. Design your oil cooler system with the engine in, I'll try to get details on mine up in my build thread in the next couple of days.
Yes dynamic and static compression are different, however i've driven a fair amount of turbo RB25DE's(10.5:1) that have been going for years. Also the obsession with E85 is not "just for dyno numbers", the cars not only run a lot better, they are faster and tuned properly with reduce emissions. I had the chance to drive a flex fueled RB, on 98 it went fairly well, on E85 on the same boost it was like a completely different car with more torque and more power EVERYWHERE. Try it before you knock it, However i do agree that pump fuel turbo engines still have a place, not everyone needs the maximum amount of power an engine can produce.
I build mine to drive on the street. My little turbo e85 build was insane. I sometimes think I should have stopped there but got turbos so why not. My car on the street with drag radials was a hell of alot of fun. Converter stalls up and it just keeps you in the seat. It was average on 98 tbo Can highly recommend just a e85 upgrade hallman boost controller and a good tune you will have a mid 11 zed. LOTS of fun especially with normal tyres :br:
