zredbaron

99% track only car. rare demonstration to a friend on an empty road. what part of the alternator mount needs to be reinforced? how did you do it? [picture?] i have the nissan comp. pulley, so at least one of the steps is complete. regarding the exhaust, the headers (stahl included) have a max of 2.5" inches on the collector as per the surfing i just did. adapt it up to 3"? the weakest link would remain 2.5"...? the exhaust step will likely have to wait for next year. those headers are quite expensive. thanks john.

ordered the sunbelt cam #2: "micro polished rifle-drilled billet ground cast iron." whatever that means. lol. .565" lift 326 deg intake, 315 deg exhaust (from .520" lift, 290/275 in/ex) with this aggressive of a cam, i was concerned about losing some low end torque, but jim was adamant that through experimenting with johnc's cams and one other customer's, the more cam they added, the more power they got and the wider and smoother the power band was. the other customer went with this cam. this cam would also give me 500 more rpm to work with. the way i calculate it, with the difference in lift, reducing gasket thickness from 2mm to 1mm, and allowing a .08 clearance, i need to cut .170 into the pistons for exhaust and .155 for intake. (jim advised more clearance on the exhaust valve) sounds like a lot. has anyone cut this much? cherry pickin and opening the engine this weekend. more updates to come.

ok, thats simple enough. i'll post my findings... thanks.

glad to be of help. i don't know nearly as much as many of the senior members, but i've learned some lessons that could have been prevented with some very simple advice/experience. the things i've done right have been because of these senior members i speak of. it's good that you're asking questions. i fell in love with the 240 when i was 17 too, so i very much relate to your excitement. it's still with me 11 yrs later when i think about upgrades. and unfortunately the dollar amounts get higher and higher the farther along your car gets... best of luck.

man, sweet tool! thanks! i definitely need valve reliefs. with the positive deck height of .025 and the lift of .525, i *have* to use the 2mm gasket. the 1mm would allow the pistons and valves to contact....

josh, most of your questions are outside the scope of this thread, but here are a few short answers. having a stroker won't give any noticable power (but you will have some torque) unless you allow its potential, even with triple webers. see my response to this thread: http://forums.hybridz.org/showthread.php?t=103763 as to your head, opening it up is a good thing. absolutely required to get power from the 3.1. in my book, if you've got it out, then you HAVE to do it. put the biggest valves in that will fit, and yes, port your head to match your gasket. if you didnt, you would have turbulent flow going into the cyls. like driving, smooth is fast. no offense, but the more experience i gain with carbs, the more i refuse to estimate jets for anyone. it varies between two different stock cars even. there are so many variables that you can only make it a science if you have the data (ie *exact* fuel flow rate (cfm), displacement, compression, rpm, etc. use your charts for a best guess starting point, then also buy a set of mains 10 above and a set of mains 10 below the charts. same with idles and air correctors, take your best guess +/- one size. (i'd vary the air correctors +/- 15 and the idles +/- 5) then go test. listen to the engine, test various throttle settings, not just full pedal, and pay attention to what your butt feels. you just gotta go do it. i bet my jet and venturi box cost me $750. just for mixture tuning. [and i still dont have it right!] [venturis are VERY expensive] dont forget that spark (spark power and timing) is just as important as fuel and air mixture. they depend on each other. just like flow and displacement. cant utilize one without the other. notice a trend? [yes! $$$!] i think i have settled on my 40s, jon. although now i'm looking to upgrade my cam to more lift, so maybe i might open that door as a possibility again. for sure staying with carbs. no 3x2 TBs for this guy. speaking of which, if you'd chime in on this thread again, i'd appreciate it! http://forums.hybridz.org/showthread.php?t=89812 this is the first i've heard of the autometer O2 sensor. and yes, that's what i've got... thanks for the tip!

i have a high flowing 3.1L stroker with 36mm venturis in my 40mm DCOEs. i autocross, so i need my full power band. i have TONS of low end torque, and a hell of a pull above 3500rpm, despite the fact that my venturis dont look like venturis (theyre practically straight sheaths claiming to be venturis!). 36mm is the biggest venturi that will fit in the 40DCOE: unless you have a VERY aggressive cam and have invested A LOT of $$$ into your head, i'd bet that 36mm is too big for you. if the head cant support the flow, opening the venturis will only help up to point. lots of useful venturi selection charts in the weber carburetors book. check barnes and noble. they usually stock a couple. basically the bottom line is, *unless you plan on road racing exclusively,* in my opinion, no one NEEDS the 45mm, despite what people tell you. my car is trailered to racing events, but even still... i'm not sure if i'll ever go up to the 45mm. you open it up too much, and you loose that low end torque/wide power band/throttle response. cars driven on the street need all of these things, especially weekend warriors which mine was for years. you might sacrifice that peak horsepower number, but chances are, off the line to 80mph isn't as fast. average power (ie power band) matters more than a peak number! as far as where to get webers... i got mine new for $1000 from victoria british when they had a special offer in '97. no advice there. (i think they changed their name to black dragon or something ricer-oriented. boo.) i have a narrow band sensor in my car and it SUCKS! it's practially worthless. its too sensitive. for the beginning carb tuner, it's very easy to not register in the band at all and have no idea if you're rich or lean. *highly* recommend wide band for carbs! good luck! (you may also want to read this thread: http://forums.hybridz.org/showthread.php?t=89812)

update: yes, i am alive...but my engine has seen better days. not sure what the cause was (possibly bad tune over time coupled with pulling vacuum off of the one cyl?), but i've been having a 5500 rpm and up hesitation/float that i thought was my ignition system. finally pulled the plugs and did a leakdown test. turns out cyl#5 has an 88% static pressure drop. yeah. you heard right. i'm pissing all that air through the intake valve. the engine upset has caused cyl #6 to leak 16% past the rings. so yeah. looks like it's time to open it all up. the good news is, i've aquired a friend that is a master mechanic and owns his own shop (my new BEST friend!), and he wants to learn me on how to do all this stuff. all i gotta do is buy him some diet coke! (score! ) the other good news here is that i'll get a real tune this time and come back with another round of dyno #s... back to the thread.... i'm thinking hey, since it's open, i might as well think about those valve reliefs! at the very minimum i'll drop the 2mm gasket to 1mm and gain the ~+1 to my CR. what i'd like is to cut them deep enough to allow for a higher lift cam, as i'll likely be putting a new one in... so... after googling and searching all morning, i've found zero guidance on cutting valve reliefs. here are my questions: do i need to buy new/custom pistons for this or can i cut the reliefs in the pistons i own? if the answer is maybe, then what do i need to look for on the pistons to know if they are thick enough or not? how deep is too deep? i'd like to be able to clear any cam (up to i dunno, .600" lift? .625?) (havent called sunbelt yet to see what their lift recommendation is, i just remember them telling me "real power isnt made until lift exceeds .550"...") any recommendation on lift if unrestricted? the application is still autocross, so i want as wide a power band as possible. at the moment, i have tons of torque available immediately and power kicks in between 3 and 3.5k and last to about 7k. (the car has evolved to slicks with camber plates and still has the strut braces.) no longer driven on the street, trailered to the races, 100LL fuel, etc. any experience in this matter would be greatly appreciated. thanks in advance!

seems i never followed up on this thread... this is how it ended up... works great!

Paul's gutted 510 racer is for sale, as is. He's asking 5500 for it, I think.

figured i'd follow through with my weekend. well, i started high, 37.5 front and 35.0 rear, working lower and lower all day. i never went so low that i noticed a decrease in performance, only an increase. i got down to 29.5 fr and 27.0 rear. really liked that. i'll try lower next time. and man, dot slicks are freakin' SWEET! haha! i was told after my third run that i was lifting my inside tire when powering out of a tight turn... that's one pic i *HAVE* to have! looks like i got 4th best raw time, bested by a gutted sti, a Z06, and an s2000. sigh... i really want that pic! but hey, in other news, on my way back from the race, my truck (trailer in tow) decided it wanted to get all squirrelly at 75mph... kuhmo truck tire! (turns out it was damaged, not a defect. the rim ripped the sidewall from the tread due to the weight of the trailer) images of my trailer and z flipping into a ditch flashed before my eyes... oh hell no!!!! managed to get it calmed down... not something I ever want to experience again!

gearheadstik, lot's of Zs came out of the woodworks today. weird, I've been pretty much the only one for the last 3 events, but today there was an ITS 240z racer and a BSP 280z, both very clean cars. pretty cool. would you be bringing your 78? what's your name, btw? and man, dot slicks are freakin' SWEET! haha! i was told after my third run that i was lifting my inside tire when powering out of a tight turn... that's one pic i *HAVE* to have! looks like i got 4th best raw time, bested by a gutted sti, a Z06, and an s2000. sigh... i really want that pic!

wow, that whois.net site needs to burn! haha. seriously, i gotta change that! Jersey: I used Microsoft FrontPage 2003 to make the site. I don't know crap about html... but the program makes it pretty easy. Basically its a bunch of clicking / pasting etc. It takes some time to figure out how to add the navigation bar at the top and stuff, but that's about it. Just upload the files to your server when done. The whole thing took about 5 hrs once I figured the program out... Thanks for the compliments, guys. Lots of love and blood (and cash! doh!) in that car... As for getting rid of the carbs one day, that's something I've always toyed with. 3x2 throttle bodies? *Very* appealing. I'm really attracted to racing with triple carbs... tuning's a bitch, but hey, that's what makes it so cool; so old skool. When you make it sing, *you* made it sing. As for getting 45s one day, hmm... I may not. Sure, I'd make more peak horsepower, but I'd also loose some low end torque. Autocross no likey not having torque... Still in the air... And yes, that's Hunt's Field you see... going there tomorrow, actually... second event ever on DOTs...can't wait. That's probably the best slab of concrete I've seen (I've visited about 6 regions, now.) Very, very nice. Sunday, Sunday, Sunday!

Davy, Yeah, that picture cracks me up... haha... definitely a classic. Glad you agree that these cars should be driven! Naviathan, Whoa! I can't believe the info you pulled! Scary, really. Would you mind sharing how you got that exactly? I'd like to make that info not public if at all possible. As for the domain, I use http://www.directnic.com for my domain service. It's like $15 a year for 2Gb bandwith, no ads, etc. Very, very cheap...

thanks! standard tranny.

I just finished my personal Z site. Nothing too fancy, but tons of pics... ranging from autocross, restoration projects, bling bling pics, etc. Also several media clips, too. http://www.markhaag.com Any comments or suggestions are always welcome and appreciated! -Mark

Thanks for the inputs. I took the car out for a test drive last night (35 psi all around), and well, god-*damn* those tires hold well! I couldn't believe the snap i could demand (1st gear full throttle from a decel... holy hell that's some grip!)...didn't ever lose traction from torque... Wow. So yeah, basically I think it's going to take some seat time before I can even notice my tires responding to different pressures. I think my first event or two I'll still just be in awe of the difference. The only thing I'll be able to measure is rollover. Hopefully I'll get a temp probe soon, too. Thanks again for the numbers. Ballpark good.

good to know, i'll start high and chalk the sidewall. in your opinion, do you think the pressure just above where rollover occurs will be best for me, or is it possible i may find the tires hook up better at a higher pressure than that even? obviously some experimentation is in order...just curious... thanks, john.

been searching the forum for awhile now, really surprised this one didn't come up! i just got a set of kuhmo v710s for my sm2 240z....just wondering what tire pressure these dot slicks like with our z cars. the size? 225/50R16 all around. i have a simple setup: tokico 5-way struts with 200fr/225rear springs. thick sways, strut braces. no camber plates yet. my kuhmo ecsta mx street tires liked to be around 37.5 for the front and 35.5-36.0 for the rear. same exact size... 225/50R16s. any recommendations would be appreciated! thanks. also, the kuhmo street tires i ran didnt like to be cooled with water between runs...the hotter the better. do these behave that way too, or do they like to be cooled? thanks again. -mark

agreed...unsprung weight just sucks. unfortunately, with my rim/fender limitations, i'm going with the kuhmo ecsta v710 DOTs for the time being. any recommended tire pressures for me to start from on DOTs? my kuhmo ecsta mx street tires like to be around 37.5 for the front and 35.5-36.0 for the rear. same exact size... 225/50R16s.

thanks tom. i just might have to pay a visit to tampa...

yeah, that's a bunch of crap that they dont make a 16x9x23-24 or something. that's pretty much the same size as my street tires, and yeah, they barely clear too. that'd be a hell of a lot more fun though. i'm not nearly as excited to run DOTs...

fair enough. thanks john. thanks for all of the responses out there. it took a collective voice to get through my thick skull that i can't have a race car that doesn't look like one. amazing, i learned some stuff about suspension, too! hah. thanks again.

haha, thanks john. i was kidding, of course. just frustrated, of course. i'm still in my 20s, so i've still got that youthful "but i want it NOW" bit of impatience. i suppose that won't ever go away, either, right? haha. the plan: get another chassis and start from scratch one day. this car i think is better off staying the way it is. i can still have fun in SM2 on DOTs. lots of fun. one last question still stands: are there any other geometry/linkage/mounts that I should consider in addition to camber plates and *slightly* stiffer springs [+25lbs] for SM2? i still like the idea of having freely moving linkage / low friction mounts. might as well maximize my finesse factor... is this question too big / too general? i've gotten the response "if you want all out, go all out"...but no one has specifically addressed what i can still do to my SM2 car. the rules say i can have "subframe connectors." should i still look into those AZC control arms / TC rods and stuff?

i hate myself.