If you're talking about genuine uncorrected sea-level HP then it depends on the true mix of that 93 octane fuel. US octane calculations are the average of two measurements, one of which is relative to boost-knock-resistance and the other not. So having a lot of the wrong one is bad because it means that you're getting less of the one you want. Dyno HP altitude correction gives a good clue as to what the hardware is capable of pumping into the motor at sea level but it says absolutely nothing about whether or not the fuel is going to knock the motor to death when you try it. ----- Original Message ----- From: Jerry Malsam To: [email protected] Sent: Monday, March 17, 2008 9:42 AM Subject: 300whp street '97 1.8L build
Spring is upon us, and the time has come to "upgrade" my old '97 1.8L FM II turbo system (230wftlb/230whp) and get the car back on the road. I've been out of the loop for a while (my excuse = Spec Miata!), so I'm looking for some current build/planning advice to reach my power goal of a *streetable* 300whp on 93 octane -- can I get there from here or am I being unrealistic? First things first, I need to cut my engine builder loose on ordering engine parts. The old engine will be mostly replaced, keeping only the stock block and crank. The old block has some taper and will need to be bored to at least 0.020" over, IIRC. (I'm probably going 0.040"/1mm over, as that leaves some room for future rebuild while allowing the use of off-the-shelf pistons.) I have a used '99 head for the project. - These coated, 9:1 FM Wiseco pistons look perfect: http://www.flyinmiata.com/index.php...10%20%201990-93 - Carrillo A-beam rods should be fine: http://www.flyinmiata.com/index.php...number=04-66005 - What prep work should I spec for the '99 head? (The FM-prepped head looks nice, but wow pricey!) Thinking ahead to the turbo system: - I had the old FM2 turbo rebuilt -- a Garrett T25/28 hybrid (IIRC), sleeve bearing, water/oil cooled -- but I'm thinking I need to just sell it and get a bigger turbo (for the hp goal) with ball-bearing (for decent spool). What is an appropriate unit that will fit the Garrett flange? Can I stick with an integral wastegate (for simplicity/cost)? My plan is to run about 230whp every day, with another 70hp on tap for "special occasions" via electronic boost control (nifty Apex'i AVC-R). - I'd like to keep the old cast log-type exhaust manifold for reliability. Will this thing flow well-enough to keep up or should I look at a tubular model? - Upgrade old FM2 downpipe? I don't know what new/improved models are out there. - I currently have RC Engineering 550cc injectors. Are they adequate to the task? I probably should upgrade the fuel pump, as I think I'm still on the stock unit. - I'm hoping to retain my old FM Link to save cost, but will upgrade to an AEM EMS if need be. (I have a good bit of experience with this ECU from tuning my friend's F Production race car.) - DDMWorks has an amazingly efficient intercooler and they can help with some cleaner, custom piping. Other bits: - I have an upgraded FM aluminum radiator, and I plan to add a real oil cooler as well. Unfortunately, I need to keep the air-conditioning for the hot/humid South Carolina summers. - I'm having the stock 5-speed tranny rebuilt. Will this thing hold up for, say, at least 20k miles in stock form or is it completely hopeless? Is it true that the later 6-speed is more reliable? - The clutch/flywheel need replacing. Looks like the FM "super-size happy meal" is the way to go, probably the lighter 10.3lb flywheel: http://www.flyinmiata.com/index.php...6000%20%2013.45 Well, that's my thinking so far; please jump in if you see something amiss or just want to confirm my thinking. I should note that while I'm a big fan of FM, I'm by no means married to them -- if somebody else is doing Great Things these days, I'm all ears! (FYI, also posted to miata.net Turbo forum) Thanks! --Jerry ------------------------------------------------------------------------------ _______________________________________________ Miatapower mailing list [email protected] http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower
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