Jon Burke Jon Burke Mod Moderator Location: San Francisco, CA Join Date: 01/03/2008 Age: Possibly Wise Posts: 1,402 Rally Car: Subaru w/<1000 crashes |
david amor Wrote:
> > Well since I have the 4.44 FD and short gears > (well RA short gears which arent THAT short) I can > tell you. I'm making alot of power so first is a > bit of a PITA. I can't grab second before the revs > are screaming to redline. I'm getting power WELL > before 3k rpm (with properly sized turbo) and with > head work I KNOW I'm making power signifigantly > beyond 5200 rpm. > interesting....I also have mild cams and headwork. sounds like even w/the restrictor, and ideal set up might be a long 1st and 2nd, and then closer 3rd and 4th....maybe stock 5th. good to know. sorry to hijack. Jon Burke - KI6LSW Blog: http://psgrallywrx.blogspot.com/ |
RallySol Eric Larsen Senior Moderator Location: San Mateo, CA Join Date: 09/05/2008 Age: Midlife Crisis Posts: 38 Rally Car: awd '93 Honda del Sol |
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low impedance Alex M. Staidle Junior Moderator Location: Colorado Springs, CO Join Date: 02/08/2007 Age: Settling Down Posts: 77 Rally Car: 1987 Mazda Rx7 |
now since making another thread, but what are the thoughts on 4.78 final drive in a 1982 Rx7 running a 13B 6 port (9.4 compression motor) with a supercharger running the stock transmission? Or since there are plenty of adapter plates on the market allowing my to run something like a ford or chevy transmission, would there be a better combo?
Tires size with probably be EITHER 14" or 15" depending on how the brake setup works out. Figuring 14" then it will probably be a 205/60R14 tire stock 12a trans: 1st: 3.622 2nd: 2.186 3rd: 1.419 4th: 1.00 5th: 0.758 stock 13B (1986-1988) trans: 1st: 3.475 2nd: 2.002 3rd: 1.366 4th: 1.00 5th: 0.711 ~A.M.S. "Some people are afraid of heights, not me. I'm afraid of widths" Edited 1 time(s). Last edit at 11/07/2008 07:58AM by low impedance. |
mellow65 Oliver Klozoff Junior Moderator Location: Oregon Join Date: 09/10/2008 Age: Midlife Crisis Posts: 480 Rally Car: Nada |
RallySol Wrote:
------------------------------------------------------- > Thought those numbers looked rather familiar. Why > swap out the whole axle when you could pull a > pumpkin out of a 2.6 Montero with 4.66 gears and > an LSD? Looking for disc brakes? > > -Eric > > Its only metal. first good luck finding one, i was on a search for a while, second, yeah i want rear discs, i just hate drums so much. at mt hood i literally had no rear brakes, i screwed with my proportioning valve the whole day and couldn't get the damn things to bite, probably miss adjusted. "Rally racing makes a heroin addiction look like a vague craving for something salty" |
RallySol Eric Larsen Senior Moderator Location: San Mateo, CA Join Date: 09/05/2008 Age: Midlife Crisis Posts: 38 Rally Car: awd '93 Honda del Sol |
mellow65 Wrote:
------------------------------------------------------- > first good luck finding one, i was on a search for > a while, second, yeah i want rear discs, i just > hate drums so much. at mt hood i literally had no > rear brakes, i screwed with my proportioning valve > the whole day and couldn't get the damn things to > bite, probably miss adjusted. > > > "Rally racing makes a heroin addiction look like a > vague craving for something salty" The LSD used in '88-'89 Starions (6-bolt axle flange) is the same unit found in the trucks, the ring swaps right over. I'm pretty sure most of the 2.6 4x4 Monteros had 4.66 gears, LSD or not. Sorry I can't help with a Mitsu based disc conversion, haven't figured that one out yet. -Eric KK6EAR |
mellow65 Oliver Klozoff Junior Moderator Location: Oregon Join Date: 09/10/2008 Age: Midlife Crisis Posts: 480 Rally Car: Nada |
RallySol Wrote:
> The LSD used in '88-'89 Starions (6-bolt axle > flange) is the same unit found in the trucks, the > ring swaps right over. I'm pretty sure most of > the 2.6 4x4 Monteros had 4.66 gears, LSD or not. > Sorry I can't help with a Mitsu based disc > conversion, haven't figured that one out yet. > > -Eric > > > Its only metal. i wouldn't have been against the mitsu stuff but finding them around here seems to be next to impossible. the rear discs, were the big thing. but enough people have swapped over toyota axles into mighty maxs that there is some info about it. the older toyota 4x4 were 1" narrower then the MM were. So a whopping half inch on each side. and then there are several companies that have rear disc swaps for the toyota. so basically it's as easy as welding on some new spring perches getting a drive line made, famous last words. but i'm tackling most of it this weekend so we shall see. "Rally racing makes a heroin addiction look like a vague craving for something salty" |
Doivi Clarkinen Banned Mega Moderator Location: the end of the universe Join Date: 02/12/2006 Age: Possibly Wise Posts: 1,432 Rally Car: 1980 Opel Ascona B |
david amor Wrote:
------------------------------------------------------- > > Well since I have the 4.44 FD and short gears > (well RA short gears which arent THAT short) I can > tell you. I'm making alot of power so first is a > bit of a PITA. I can't grab second before the revs > are screaming to redline. I'm getting power WELL > before 3k rpm (with properly sized turbo) and with > head work I KNOW I'm making power signifigantly > beyond 5200 rpm. > > > Edit: I know I'm making enough power that I don't > NEED short gears but I don't NEED alot of things I > have but I can still WANT them. > Well, if you want to replace broken ring and pinions a lot then by all means run the 4.44's. But if you've got a lot of power I would recommend the 3.90's. |
Cosworth Paulinho Ferreira Godlike Moderator Location: Charlotte, NC Join Date: 03/15/2007 Age: Midlife Crisis Posts: 721 Rally Car: Honda Civic |
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david amor david amor Mod Moderator Location: Stoney Creek Ontario Join Date: 03/22/2006 Age: Possibly Wise Posts: 458 |
Doivi Clarkinen Wrote:
------------------------------------------------------- > david amor Wrote: > -------------------------------------------------- > ----- > > > > Well since I have the 4.44 FD and short > gears > > (well RA short gears which arent THAT short) > I can > > tell you. I'm making alot of power so first > is a > > bit of a PITA. I can't grab second before the > revs > > are screaming to redline. I'm getting power > WELL > > before 3k rpm (with properly sized turbo) and > with > > head work I KNOW I'm making power > signifigantly > > beyond 5200 rpm. > > > > > > Edit: I know I'm making enough power that I > don't > > NEED short gears but I don't NEED alot of > things I > > have but I can still WANT them. > > > > Well, if you want to replace broken ring and > pinions a lot then by all means run the 4.44's. > But if you've got a lot of power I would recommend > the 3.90's. > Hey I'm trying as hard as I can to break the 4.44 box so I can get a nice 3.9 6 speed. Launch control, antilag, I mean what else can I do? Gone fishing |
Have you considered the exagerated tendency for wheel spin in a light rear end of a truck? For that reason, I would tend to limit the wheel torque to avoid too much wheel spin; that would say to not go one step less steep on gear ratio than a car, assume a 4 gear truck for rallying, and 5th only for transits and that rare, really fast stage straightaway.
Which brings up an associated question and a side topic: On RWD, you can always help the rear step out with a stiffer rear anti-sway bar or springs. But will the vehicle be faster if you softened the rear springs/shocks and anti-sway bar, and increased the torque on the wheels? (I have never really mused over that trade-off; it was always 'use the gears you have' and then change the suspension to get the balance.) I would like to hear folks' thoughts on that trade-off. Regards, Mark B. |
Haztoys David Rodgers Senior Moderator Location: Prescott Valley AZ Join Date: 03/16/2007 Posts: 165 Rally Car: 90 Mitsu truck ..And needing something new just not sure what..??? |
Whats your plan here.. Yes I know I'm coming in to this on "Third Act" ..Sorry..
But what class is the truck to be raced in ... And motor info...Tire size.. Fast rallys or Tight rallys..?.... if you could ...Hard to say the gear with out more in fo...I have alittle "hands on" on this subject.. David Hazardous Toys inc |
mellow65 Oliver Klozoff Junior Moderator Location: Oregon Join Date: 09/10/2008 Age: Midlife Crisis Posts: 480 Rally Car: Nada |
Haztoys Wrote:
------------------------------------------------------- > Whats your plan here.. Yes I know I'm coming in to > this on "Third Act" ..Sorry.. > > But what class is the truck to be raced in ... > And motor info...Tire size.. Fast rallys or Tight > rallys..?.... if you could ...Hard to say the gear > with out more in fo...I have alittle "hands on" on > this subject.. > > David > > Hazardous Toys inc don't worry the good stuff doesn't start till act 4. (sorry lame humor) i'm running in G2, open 2wd non turbo, most the rallys around here are twisty, no major straits, not to say they aren't out there. wild west is about the old big drag race, i had the time and distance to break a 100 in my non turbo legacy. motor, after talking to past owners, 2.4 milled head, porting, "rally" cam (what ever that means) balance shaft eliminator. Pretty peppy on the upper end of the rpms, but the motor had a decent stroke to it so it wants to be more torquey, then say a toyota truck motor. tires, BF goodrich AT, 215/75 15, 27.7 inches tall. tranny gearing 3.369 2.035 1.36 1 0.856 factory power, 116hp @ 5000rpm 136tq @ 3500rpm so expect a little more with the "work" done to the motor. so what do you think? "Rally racing makes a heroin addiction look like a vague craving for something salty" |
krisdahl Kris Dahl Junior Moderator Location: Issaquah, WA Join Date: 02/13/2006 Age: Midlife Crisis Posts: 282 Rally Car: Integra, Civic |
John,
Yeah the graph is really inspired by video games which use this layout. Ultimately it IS a graph of RPM--or actually MPH which is the same thing. I've got a beta version of the system that will actually take your dyno plot and graph the torque at the wheels and also give you your shift points based on (so far with the ones I've done it is always at redline). |