Nismo S30 Posted December 6, 2006 Share Posted December 6, 2006 I want to autocross. I need something small and light. and N/A. I'm thinking sr20de with vg pistons to raise it to 12:1. ITB's and supporting mods. race gas of course, its not a daily driver. help me out. Brendan Quote Link to comment Share on other sites More sharing options...
Lunar240z Posted December 6, 2006 Share Posted December 6, 2006 http://www.sr20forum.com/forumdisplay.php?f=47 Quote Link to comment Share on other sites More sharing options...
Hugh Posted December 6, 2006 Share Posted December 6, 2006 I'm thinking SR20VE. There's a guy with a 510 running one making like 200hp. He seems to love it. The power band is sorta honda-ish. It builds to almost redline. A small turbo'ed SR can make a lot more power with a fat torque band... even the stock T25 pushes 250hp. Mine spools around 2500rpm and makes power to beyond 6000rpm. I'd say thats fine for autocross. (just a thought) Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 6, 2006 Share Posted December 6, 2006 That's going to push you into a Mod class. If you really want to compete, build the L. If you want to build what you want, regardless of the rules, then build your SR. Personally I think you'd have a hard time overcoming the displacement disadvantage by going to a smaller engine. A tweaked 12:1 compression L28 should make 250-270 whp I would think. My L28 at 11:1 makes 240ish, and I built it in my garage. Quote Link to comment Share on other sites More sharing options...
Nismo S30 Posted December 6, 2006 Author Share Posted December 6, 2006 That's going to push you into a Mod class. If you really want to compete, build the L. If you want to build what you want, regardless of the rules, then build your SR. Personally I think you'd have a hard time overcoming the displacement disadvantage by going to a smaller engine. A tweaked 12:1 compression L28 should make 250-270 whp I would think. My L28 at 11:1 makes 240ish, and I built it in my garage. You have a valid point... On 11:1 how much do you have in the way of head mods? If you could PM me a rough mods list so i can see what you're doing to pull 240ish out of 11:1 that would be great! Also, how is your weight distribution? are you having to cope with a lot of oversteer thanks to the larger weight in the front? my main reason in wanting to swap to an N/A SR was having a better center of gravity, lighter overall, and better handleing thanks to this... Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 6, 2006 Share Posted December 6, 2006 My car with a full interior, extra sound deadening, an Autopower roll bar and R200 diff had the following corner weights with my ~180 lb ass in the seat: LF: 640 RF: 620 LR: 650 RR: 640 That is 49.4% F and 50.6% R, with a cross weight difference of 10 lbs. and total weight of 2550 lbs. Take my weight out and you get a car weight of 2370. That was with a 1/2 tank of gas. As far as head mods I have an E31 with 280 valves, unshrouded the valves polished the chambers and the block is notched to match the head, larger intake seats installed, ported head, port matched Cannon intake, 44 Mikunis, ITG filter. Cam is a regrind .490/280. The chambers were cc'd, then the head milled, which is why I don't know the exact compression ratio. The bottom end is basically stock L28 with flat top pistons. ZX distributor with no vacuum advance, MSA POS 6-1 header into 2.5" mandrel exhaust. That's basically it. Quote Link to comment Share on other sites More sharing options...
phantaz Posted December 6, 2006 Share Posted December 6, 2006 MSA "POS" 6-1 header into 2.5" mandrel exhaust. That's basically it. i dont know why..but that made me chuckle =) Quote Link to comment Share on other sites More sharing options...
Nismo S30 Posted December 10, 2006 Author Share Posted December 10, 2006 Ok I've decided to keep the L28 to keep from getting bumped a class. I didnt know that my weight balance was that good. I weigh 170 and my interior is completly stripped. I have an 8 point 2" roll cage though, so it sorta replaces the weight. Did you do your own head work? Brendan Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 11, 2006 Share Posted December 11, 2006 Yeah, I did most of it. The machinist who originally installed the larger intake seats did some work in the bowl on the intakes, but that was about it. The rest I did myself. I focused mostly on the chambers, unshrouding the larger valves in the E31 head. The ports aren't opened up very much at all. There are lots of threads on L series headwork, and a lot of people go much farther with it than I did. Check out BRAAP's head building thread in the L6 forum, get a copy of the How to Modify book, and STUDY the pictures in there. Take your time. I might be one of the minority on this issue, but I think just about anyone can do a decent porting job, just don't go insane with a grinder and I'm sure you'll do fine. 2" rollcage? Prepping for WWIII??? Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted December 11, 2006 Share Posted December 11, 2006 yeah 2" is a little overkill...LOL Quote Link to comment Share on other sites More sharing options...
Nismo S30 Posted December 12, 2006 Author Share Posted December 12, 2006 lol, im just affraid of getting hit! No, its acually 1.5". I dont know what I was thinking. I'm going to get that book. I'm glad I already have a spare head to practice on. Quote Link to comment Share on other sites More sharing options...
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