240zdan Posted October 13, 2009 Share Posted October 13, 2009 i manged a 12.6@118mph 2.45 60 foot. the car has absolutley no traction in 1st or 2nd gear. my excuses are as follows (doesnt everyone always have those?) 3.3 open r200 (trapping almostr 120mph in 3rd gear) 12 psi boost, i tried inceasing to 1 bar but it would just spike to 1 bar and then settle to 12 psi. 48psi fuel pressure, a bit rich stock rb26 (thats right, stock... by that i mean stock rb26 mafs, stony. and stock conservative ecu.. hahaha) next season i plan to push the stock twins to a 125mph + trap and a high 11 on streets, i think the 4.11 lsd and a ebc will do it. i was also getting alot of wheel hope in 1st, but none in 2nd. i will change the rear lca bushings hopefully it will fix that. car feels awesome on the street i can only imagine 14.7 psi to redline. Quote Link to comment Share on other sites More sharing options...
stony Posted October 13, 2009 Share Posted October 13, 2009 How many times did you run???? 12.8 was my very first run and i managed to get it down into the 11.5x range by the end of teh day playing around with where i launched at rpm wise. if you can keep the rearend together you can get into the 10s pretty easy. I was at 390 rwhp and the best i got was a 11.138 with a 1.9 60 foot or something like that Quote Link to comment Share on other sites More sharing options...
stony Posted October 13, 2009 Share Posted October 13, 2009 Here was the very first run ever down the track http://videos.streetfire.net/video/rb26-first-run-ever-down_8815.htm Quote Link to comment Share on other sites More sharing options...
240zdan Posted October 13, 2009 Author Share Posted October 13, 2009 How many times did you run???? 12.8 was my very first run and i managed to get it down into the 11.5x range by the end of teh day playing around with where i launched at rpm wise. if you can keep the rearend together you can get into the 10s pretty easy. I was at 390 rwhp and the best i got was a 11.138 with a 1.9 60 foot or something like that i ran 3 times. 2nd time there was moisture on the track and i ran a 13.9 not really worried about 1/4 mile time other than the fact that i want to run a 11.9 on streets next year. the 1/4 ile is so dependant on 60 foot, and im not properely suited for launching the car at higher rpms with slicks. i was launching the car at idle when i ran those times. im concerned about trap, as this tells me what the car is capable of on the street at highway speeds. i think traping at the end of 4th would be beneficial. i dont need a 200+mph top speed anyways i cant wait to get the 4.11 in Quote Link to comment Share on other sites More sharing options...
EMWHYR0HEN Posted October 13, 2009 Share Posted October 13, 2009 Impressive times! I think 4.11 might be a bit much for and RB26 S30. If your having traction problems with 1st and 2nd your going to have even more problems with a 4.11. I'd look at a 3.5 or 3.7 at the most. Leave the 4.11's for underpowered NA cars. Quote Link to comment Share on other sites More sharing options...
Sparks280zt Posted October 13, 2009 Share Posted October 13, 2009 Turbo cars run higher times with a shorter gear, a 4.11 is way to tall for your set up. Ask Z-gad, everytime he swapped in a shorter gear he went faster. Quote Link to comment Share on other sites More sharing options...
240zdan Posted October 13, 2009 Author Share Posted October 13, 2009 A 4.11 will be ideal since i am using a z32 N/A tranny. I have calculated the top speed in 4th using a gear ratio calculator and gear ratio specs for a z32 n/a tranny and it will put me at redline in 4th at the end of the 1320, with a top speed of about 150mph+ in 5th. cruising rpm in 5th will only raise about 500-700rpms. With a clsd and a set of radials i think a 4.11 will really let the car perform to its full potential.. besides, this is what the r32 gtr came with stock (granted its awd, but still a rb26 s30 will have no traction, and rwd high hp will have no traction with street tires. gearing wont solve this issue) the rb26 is also a little soft on bottom end power so the gearing should help there. Quote Link to comment Share on other sites More sharing options...
240zdan Posted October 13, 2009 Author Share Posted October 13, 2009 Turbo cars run higher times with a shorter gear, a 4.11 is way to tall for your set up. Ask Z-gad, everytime he swapped in a shorter gear he went faster. Im almost certain i will run a faster timer with a 4.11 I think it would be on the verge of breaking loose in 3rd with a 4.11 with the amount of power it has right now, and then once it would be put into 4th to redline the acceleration would be much quicker than a long 3rd. im sure 100 or so more hp would be a different story. Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted October 13, 2009 Share Posted October 13, 2009 I'm using a 3:7 lsd, and I think it's just right (rpm wise). Granted, I have not ran it at a track, but I have done quite a few country road wide open pulls, so I think it will do fine once I finally take it to a track. I have a 4:11 clsd that I have not tried yet, so if I find it's needed down the road, I already have one.... I think you will benefit from stepping up from your 3:3 diff though... Quote Link to comment Share on other sites More sharing options...
240zdan Posted October 13, 2009 Author Share Posted October 13, 2009 yeah the 3.3 is horrible, it would be ok if i had a v8 with 600hp but not for a little 2.6 Quote Link to comment Share on other sites More sharing options...
neotech84 Posted October 13, 2009 Share Posted October 13, 2009 .........With a clsd and a set of radials i think a 4.11 will really let the car perform to its full potential.. besides, this is what the r32 gtr came with stock (granted its awd, but still a rb26 s30 will have no traction, and rwd high hp will have no traction with street tires. gearing wont solve this issue) It also weighed 3300+lbs!!! You have to take that into account. You are sitting at what around 25XXlbs and some change. Quote Link to comment Share on other sites More sharing options...
240zdan Posted October 14, 2009 Author Share Posted October 14, 2009 It also weighed 3300+lbs!!! You have to take that into account. You are sitting at what around 25XXlbs and some change. Weight wouldnt have an effect of my gearing choice. My gearing choice is dependant on top speed, cruising rpm, and what gear/rpm i wish to be at the the end of the 1/4 mile. the 4.11, along with the holset hx40 pro and supporting mods is what im going with. Quote Link to comment Share on other sites More sharing options...
Careless Posted October 15, 2009 Share Posted October 15, 2009 why 4.11? I was considering that too, but I have some friends in the know... they're telling me that if you're going for big boost, you'll run out of gear, top end, and most importantly, have to shift more often, thus loosing a lot of the boost you build through that short gear. At that point you'll go no where. you will be slower with the 4.11 the 240sx has a 4.06 I think, and there is also the 3.9 from the Z31. perhaps those are better options? For an ultra responsive turbo application, like say, a small turbo on a higher compression motor... makes sense. HX40? 4.11? i dunnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnno. would like to see how it works out. Quote Link to comment Share on other sites More sharing options...
240zdan Posted October 15, 2009 Author Share Posted October 15, 2009 The reason why I choose 4.11 -Found one for cheap with CLSD with very low kms -Its what the GTR came with stock -It will improve acclereation and I will run a faster time, to those of you who say ill run slower, this is true if i have 600+hp thats why people go with 2 speed powerglides, but my car is sluggish of the start and does not utilize all 5 gears, or at least 4 I have seen it before with other cars a taller gear is worth .5 second in the 1/4 if youre still putting out relativley low power. I dynoed 310whp and consider this to be relativley low. Tell you guys what I will try it out and run the car at the exact same boost level next year and tell you the results. If I dont get the results I want good part is I can always swap in another shortnose r200 with different gearing once I have all the fab work done. Quote Link to comment Share on other sites More sharing options...
Slammed68 Posted October 15, 2009 Share Posted October 15, 2009 My very first run with a cam only LQ4 6.0L was a 12.3 @ 114, dying up top because of a horrid tune. Got a 1.9 60ft on some VERY bald, rock hard street tires, and no traction down low. Seems like you're on par for going a little faster My car with the same 114 trap setup would hang with 125 trap cars from a roll on the street, so track traps unless youre hooking dont mean a thing. Quote Link to comment Share on other sites More sharing options...
Pyro Posted October 15, 2009 Share Posted October 15, 2009 For drag racing you need to install stronger springs in the rear and run stock springs up front. This will cure the wheel hop plus help put the power down on the wheels. On take off, you need the front to lift and the rear to stay steady. This looks very similar to the rear squatting and the front steady (which is a bad thing). So weak springs up front and strong in the rear is what you need. Heavy springs in the rear and soft up front also fixes understeer, which plagues most z's. Rarely does a drag racing setup help handling, but it does on a z. 118 mph trap should already be a high 11 run. How old are your tires? Fresh rubber helps a lot more than you would think. Gears will also help. 3.3 is not enough. my 240 with a 5 spd, 350 cid, and 200 shot of N02 ran quicker with a 3.90 gear than with a 3.54. when it comes to drag racing, you need gears. Quote Link to comment Share on other sites More sharing options...
stony Posted October 15, 2009 Share Posted October 15, 2009 The reason why I choose 4.11-Found one for cheap with CLSD with very low kms -Its what the GTR came with stock -It will improve acclereation and I will run a faster time, to those of you who say ill run slower, this is true if i have 600+hp thats why people go with 2 speed powerglides, but my car is sluggish of the start and does not utilize all 5 gears, or at least 4 I have seen it before with other cars a taller gear is worth .5 second in the 1/4 if youre still putting out relativley low power. I dynoed 310whp and consider this to be relativley low. Tell you guys what I will try it out and run the car at the exact same boost level next year and tell you the results. If I dont get the results I want good part is I can always swap in another shortnose r200 with different gearing once I have all the fab work done. Everything you said is true... you will go faster plain and simple... i did it so i will speak from experience. you are on the right track. what you have to also remember is with taller gears you are transmitting more torque thru the drivetrain. this means if you hook up good with good DR the potential for breaking rearend parts has greatly been increased. good luck Quote Link to comment Share on other sites More sharing options...
RS Speed Posted October 15, 2009 Share Posted October 15, 2009 I like long gears on a turbo car as much as the next guy but I don't want chevy tahoe gearing. I like my cars to do ~100 on the top of third, 120 is too long and would definitely slow down acceleration. Quote Link to comment Share on other sites More sharing options...
240zdan Posted October 17, 2009 Author Share Posted October 17, 2009 track traps unless youre hooking dont mean a thing. please explain this. i understnd traps go down slightly when u hook but i dont believe that traps dont mean anything. they are a good indication of your power to weight, and a good indication of your lack of traction. Quote Link to comment Share on other sites More sharing options...
Bernardd Posted October 17, 2009 Share Posted October 17, 2009 My car with the same 114 trap setup would hang with 125 trap cars from a roll on the street, so track traps unless youre hooking dont mean a thing. This is not correct. I have trapped at 115mph running from 14.9sec down to 12.0. My 60ft was the only thing that changed. This is the best way to tell/test if you or your bragging buddies dyno is acurate or b.s. You need the weight of the car and a trap speed. You'll find many guys that have "the highest dyno of xyz configuration ever" but either won't run at the track because don't understand how it works or they won't go because they know how it works and want to keep their baller status. Quote Link to comment Share on other sites More sharing options...
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