Jump to content
HybridZ

TRACTION PROBLEMS??


Recommended Posts

Will BFG g-force drag radials 225/45 R17 and a RB26 pushing 400HP at the tires be a problem at the track, I'm shooting for low 11 sec 1/4's for now, is it going to be possible?

That is if they let me on the track with no door handles?

 

here is some info on the car

 

1973 240Z (-) = I have (*) = I want / need

 

motor

- R33 RB26DETT

- 3†stainless exhaust with Dynomax Ultra flow muffler

- Stock fuel tank modified

- Apexi GTR intercooler (on back order)

- Areomotive 700hp coffee grinder / fuel pump

- SDS computer

- HKS boost controller

- HKS blow off valve

* two K&N filter

 

transmission

- GTS-T 5 speed

- quick shifter

- O.S clutch

 

diff

* LSD r200

* ZXT CV’s

 

body

- House of color “Kandy Organic Greenâ€

- shaved marker lights and door handles

- tint

- Xenon air dam

 

interior

- Momo steering wheel

- Momo shift knob / boot

- laser cut aluminum fan / vent / heat / five 2-1/8 gauge panel

-/* Auto meter gauges ten of them (I only have a air/fuel and exhaust temp at the present time)

- Viper alarm

* roll bar

* Corbeau seats / belts

 

wheels / suspension / brakes

- Motegi MR7 17x7 wheels

- BFG g-force drag radials 225/45 R17

- Ground Control coil overs

- Tokico 5-ways

- Energy suspension bushings

- SCCA rear 240sx /300zx rear brake kit

 

z-rb1.jpg

 

rb2.jpg

 

www.rb26dett.freeservers.com

Link to comment
Share on other sites

Can you bump up to 245? I'm pretty sure that's what I've got under my rear fenders and any added traction you can get would be good. I never really got on my car very hard as I was breaking rear bits but spinning over 555R Nittos wasn't hard and they were 245s!

Link to comment
Share on other sites

Brad,

Assuming you stick with your current rims, 235 is the largest you can really run on a 7in rim.

Needless to say you will have traction issues. I would suggest getting everything running first, take it to the strip with the existing rims/tires second. Then run it and see what the problems are. Then I would invest in a second set of rear rims that are backspaced to get you up to at least an 8 in, or a 9 or 9.5,(look at Pete P for that spec, basicly coilovers and a certain backspacing). That will allow a bigger tire. For stock fenders, I would run a 9 in rim and run the extra tire,(likely 255 is as big as you can go in the rear w/o hitting the fender, assuming it is rolled). If you go to a 9.5 in rim like Pete, you will have little sidewall for the Drag radial to flex.

And BTW, it turns out my motor won't be in till the 17th, so no clutch for you till at least then. And in reality, it will take some time for me to get it out of customs. I will try to get it out before I leave for my parents and Christmas,(the 20th), but if I don't, then you'll be waiting till the 3rd of Jan.

-Bob

Link to comment
Share on other sites

To extend on Bob's response, I had no traction with 275/40-17s after consistent low-1.60s with 275/50-15 and 255/50-16. The sidewall is just too short and stiff, but since you already have them, give it a shot. As a comparison, RickB is spraying a SBC and ripping off the line with 235/60-15s.

 

I ended up doing as Bob is advising. If they do not work, get a pair of 15" rims and and run the 235/60-15 DRs at the track. On the street you will need those DRs unless you like showing how you can spin tires nono.gif . However, I wonder how much better the newer BFG DRs are in the wet and tread wear? The older ones were horrible.

Link to comment
Share on other sites

Originally posted by Scottie-GNZ:

However, I wonder how much better the newer BFG DRs are in the wet and tread wear? The older ones were horrible.

I ran the G-Force DRs on the street for a bit this fall (215/60/14). I absolutely hated the soft sidewall, I always felt like I had to granny around the turns (they stick, but they are sloppy). I also drove them a bit in the wet with no problems, but I was, of course, taking it a bit easy. They seem to be ok... coollook.gif
Link to comment
Share on other sites

My fenders are not rolled, so how wide could i go? i will switch to 8" springs for more clearence.

 

Bob H dont worry about the clutch, I'm in no rush. just got my areomotive 700hp fuel pump

img-5-1-large.jpg

 

and filter. and ordered a the new HKS EVC.

 

L_1652.jpg

 

GNZ i had the tires and rims on my girl's 02 civic, and the DR's were better in the wet than the stock tires that came with the car. seriously.

Link to comment
Share on other sites

I also am running 215 60 R14 BF Goodrich DR's. I had heard they were bad in the wet, so I was very careful at first, but have found them to stick better than my street tires in the wet. At the track I am almost dead hooked, and run 1.74 60's. I wish I could find some 15" pansport whells with 15 to 20 mm pos offset so I could run 235 60 R15 BFG's. I have to leave the line at 700RPM now to keep traction. If I try to raise the rpm, then the tires will spin a couple of revelotion causing 1.9 60's nono.gif

Link to comment
Share on other sites

I don't have an RB26, but twinturbo L28 with NOS. I don't know if it was track prep, but the Nitto 275-50/15's did not hook for crap in Montegomery. I was spraying 100shot nitrous and 10psi out of the hole and spinning the tires every time. I could only muster a 1.9 60ft with 11.2@129.45. I suspect the nitrous played a roll in the problem. The nitrous hits so hard I think the tire cannot handle such a quick transition from still to moving. This was also with an auto trans, so it was not like I droped the clutch. I doubt this helps, but I think you will want to get some slicks!

Link to comment
Share on other sites

Scottie-GNZ

I think i should have around 400HP but we will see. I'm running it on a dyno to tune it, so i will know then. i was just going by stony's #'s, but he dose have bigger 680cc injectors. i think mine are around 440cc.

 

stony's dyno slip

2227clintdyno-med.jpg

 

and will it be hard to pull off a 1.80 60' with my 225 DR's? because 11.20 sec is how fast i would like to be, i think that is fast enough me.

Link to comment
Share on other sites

It is a lot easier (but more expensive) to make more HP for a big MPH than it is to get the car to launch hard for a quicker ET. ET wins races, MPH is a HP indicator and bragging rights. I had no success with 17" Nittos (275s) and I doubt the 225s will do the job with 400rwhp. Try it and then decide. If you are going to get a 2nd pair of tires for the strip, then do what I did and get a pair of Hoosier QTPs. They are DOT-legal but you do not want to be driving on the street with them a lot. I live 9 miles from the track and they never see an inch of road beyond that.

 

However, throwing those on will not guarantee you 1.45s like I am getting. Getting the suspension set up is also key. The average street shock is going to compress/rebound normally and that is not what you want for the strip when looking to break into the 10s. A street car will need adjustable shocks, like Illuminas, or sacrifice the launch with wheelspin or worse, wheelhop. You want the front to rebound quickly and compress slowly and the rear to compress quickly and rebound slowly. This will give instant weight transfer and not unload the rear too quickly. Ever see a turbo launch then start spinning the tires 20' out when the big boost comes on? The Illuminas allow you to make that suspension adjustment for the strip and back to carving canyons if you have to.

 

Thats one of the main problems with your car James. Even spraying out of the hole, I doubt your setup has more low-end torque than mine, yet I was cutting low-1.60s on a t-brake with the same DRs you have with nary a trace of wheelspin.

 

If you are serious about getting QUICK ETs, then think about this: for every .1 on the 60' you affect the ET by .15. The first 1/8-mile is spent building acceleration and the 2nd half is for top-end MPH. With your 11.2 you are going to spend ~7.15 to run the 1/8-mile and ~4.14 to run the 2nd half. How important is the launch in drag racing?

 

BTW, lets not start the rear-end squatting debate again :D:D:D

Link to comment
Share on other sites

Oh, and Scottie-GNZ

What size fuel line do you have?

my new pump's inlet is -8 and exit is -6 and it is rated for 700HP.

 

I'm in the middle of making a sump on my stock gas tank. i was going to dump out of the sump with two -6's in to one -8 into my filter then through my pump and exit the pump at -6, to the rail past the regulator and back to the tank with a -6. :D

 

thanks smile.gif

Link to comment
Share on other sites

I still have the fronts and set them to "1" for the strip and "3" for the street. If I recall, the rears were set the same way. Can't believe I have already forgotten. Must be having "senior" moment :D .

 

I currently run -8 inlet and the stock 240 inlet for my return.

 

I would imagine 5.5" BS should work but maybe someone who has that same combo can chime in.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...