Lq4 hci +175shot 260z Goes racing

[DcrDavid]

Well after a couple track outings I was looking to hit 2 of my goals in one day. 170mph in the 1/2 mile and 9.9x@140+ in the quarter. With a welded r200 and stock half shafts.

 

Mods:

lq4 iron 6.0 9.4:1 compression

cnc ls3 heads

mild boost cam

1 7/8 arh headers

Nx Proton 175 shot

M12 T56

Aluminum flywheel w/ mcleod rst twin disk

429whp/398wtq on motor

603whp/625wtq on 175 shot

~2600lbs

 

So loaded the car up since there was a high chance of destruction over the weekend and headed out to coalinga for the 1/2 mile event. First pass on the nitrous went 170.2mph. So took the bottle out to run na to save it for the 1/4 mile. Next pass was N/A and went 152mph. Perfect thats one goal of the list. 

 

Loaded the car up and headed to sacramento raceway. 3.5hrs later got to unloading the car. First pass broke a half shaft. I had brought 2 spares so 20 minutes later was ready for another pass. Did a soft launch, 1.7 60ft, as to actually make it to the end and missed 4th gear and went 10.2@142. Next pass clicked off a 9.9@142 on a 1.5 60ft. Now thats 2 goals in one day so decided to try for a little more. Last pass I got a bit more aggressive getting on the nitrous in first. And went 9.84@143 on a 1.49 60ft. 

 

Couldnt be happier with how the car performed and still speechless how the one axle i had the least faith in held in the longest. Just 10 months ago the car was a bare roller. Now its time for a little more power.

 

Its been going at this power level since August of last year and really the only casualties have been 5 half shafts. And my z emblem falling off when i grenaded both half shafts at once. Cars been over 170mph a handful of times with countless pulls. Its been a ton of fun and that was the main goal of the build.

[Richard Oben]

Nice goals and way to go get them!  I think real half shafts are in you future...  Nice job!

[weedburner]

Add something like my ClutchTamer and you will likely be able to get a lot more from your halfshafts. Pretty easy to diy a similar solution once you understand how my solution works, here's a link to my version of a clutch hit controller... LINK

 

Grant

 

[DcrDavid]

5 hours ago, Richard Oben said:

Nice goals and way to go get them!  I think real half shafts are in you future...  Nice job!

 

Thanks! Im planning on moving to a better diff and the welded diff gets kinda old sometimes. 

[DcrDavid]

5 hours ago, weedburner said:

Add something like my ClutchTamer and you will likely be able to get a lot more from your halfshafts. Pretty easy to diy a similar solution once you understand how my solution works, here's a link to my version of a clutch hit controller... LINK

 

Grant

 

 

 

My biggest issue is i was using my 2 step set around 5-5800rpm and doing a quick dump and it was too violent for the half shafts. So last outing i ditched that. And still launched around 5200rpm but feeding the throttle in as I let the clutch go. And theyve been fine.

[weedburner]

With a hit controller you will be able to launch at 7500 off the 2step with a quick clutch dump, and rpm won't fall below your torque peak. You have the potential to shave about .5sec off of your ET and I think you can do it with your existing halfshafts.

 

Although not IRS, my car has been 5.73 in the 1/8 with a 1.30 60' , also manual trans + radials and dead hook launches. About 225hp plate on a 1 sec delay. Super aggressive full face sintered iron clutch, but it's hit controlled to the point that the hit is spread over about 1.0 sec vs about 0.3sec without a hit controller. Without a hit controller, my car twists a 2-1/2x.065" driveshaft almost instantly. With the clutch hit controller, same 2-1/2"x.065" driveshaft has been in the car since 2012. 

 

Grant

 

[DcrDavid]

23 hours ago, weedburner said:

With a hit controller you will be able to launch at 7500 off the 2step with a quick clutch dump, and rpm won't fall below your torque peak. You have the potential to shave about .5sec off of your ET and I think you can do it with your existing halfshafts.

 

Although not IRS, my car has been 5.73 in the 1/8 with a 1.30 60' , also manual trans + radials and dead hook launches. About 225hp plate on a 1 sec delay. Super aggressive full face sintered iron clutch, but it's hit controlled to the point that the hit is spread over about 1.0 sec vs about 0.3sec without a hit controller. Without a hit controller, my car twists a 2-1/2x.065" driveshaft almost instantly. With the clutch hit controller, same 2-1/2"x.065" driveshaft has been in the car since 2012. 

 

Grant

 

 

That sounds good if I wanted to get more into competitive drag racing. But its just for fun for me. 

[weedburner]

So .5 sec quicker in the 1/4 for less cost than re-filling a nitrous bottle doesn't sound like fun to you? 

 

Grant

 

[DcrDavid]

Id rather figure out the 3rd pedal for myself or go auto.

[weedburner]

Might as well go straight to auto now, that will be more fun than the hit and miss results of trying to control the hit with your left foot.

 

Grant

 

[Richard Oben]

Hope this works.  Porsche CV with 8.8 IRS.

 

[DcrDavid]

21 hours ago, weedburner said:

Might as well go straight to auto now, that will be more fun than the hit and miss results of trying to control the hit with your left foot.

 

Grant

 

Ive only tried 3 times since getting rid of the 2 step and all 3 passes were faster than my best with the 2 step im having a great time.

[weedburner]

New bests are always a great time

 

But drag racing is addictive and I think you will find yourself looking for more. Your current best is 9.84, but 143mph is enough power to run 9.20's. For an automatic car, most of what it takes to achieve a 9.20 level of efficiency comes from finding a proper torque converter that slips just enough to let the engine make the most of it's power band. For a manual trans car, the equivalent to the right torque converter is finding just the right amount of clutch hit that doesn't cause bog, spin, or broken parts. All three of those things will reduce your fun factor, and all three are caused by a clutch that's allowed to hit too hard. Yours is also a nitrous car, so the definition of a clutch that's allowed to hit too hard changes when the bottle is turned on or off.

 

Some may find it hard to believe, but a proper hitting clutch will hit your halfshafts with less intensity than the equivalent auto/converter. Proper clutch hit management also makes it possible to use radial tires effectively. This also tends to improve the fun factor, as you pick up a few more mph while eliminating the need to swap tires between street/strip.

 

All just friendly suggestions, took me a long time to figure it all out.

 

Grant

[SH4DY]

Is that 2,600# with driver? I had always thought these were around 2,300-2,400# wet.

Also, I'm really digging the wheel/ tire combo. Mind sharing the specs on those?

[DcrDavid]

On 5/10/2019 at 9:21 AM, weedburner said:

New bests are always a great time

 

But drag racing is addictive and I think you will find yourself looking for more. Your current best is 9.84, but 143mph is enough power to run 9.20's. For an automatic car, most of what it takes to achieve a 9.20 level of efficiency comes from finding a proper torque converter that slips just enough to let the engine make the most of it's power band. For a manual trans car, the equivalent to the right torque converter is finding just the right amount of clutch hit that doesn't cause bog, spin, or broken parts. All three of those things will reduce your fun factor, and all three are caused by a clutch that's allowed to hit too hard. Yours is also a nitrous car, so the definition of a clutch that's allowed to hit too hard changes when the bottle is turned on or off.

 

Some may find it hard to believe, but a proper hitting clutch will hit your halfshafts with less intensity than the equivalent auto/converter. Proper clutch hit management also makes it possible to use radial tires effectively. This also tends to improve the fun factor, as you pick up a few more mph while eliminating the need to swap tires between street/strip.

 

All just friendly suggestions, took me a long time to figure it all out.

 

Grant

 

 

Yup all good. My last car was auto shattered the record for bolt on base c6 corvettes. 10.42@128 with 417whp so im no stranger to autos and i know it would be way faster auto. Give me a year or so and i can almost guarantee it will be.

 

and as far as wanting more i got it covered. More horsepower coming soon lol. But i get what you mean with the frustration of stick cars. Thats why my last one was auto. Got tired of breaking stuff in my subaru and camaro. The corvette was great. I had over 600 passes at the track most of which were cutting 1.4 60fts to a best of 1.37 and never broke anything drivetrain wise.

[DcrDavid]

6 hours ago, SH4DY said:

Is that 2,600# with driver? I had always thought these were around 2,300-2,400# wet.

Also, I'm really digging the wheel/ tire combo. Mind sharing the specs on those?

 

I dont know why but my car is in the heavy side. It is an iron block so that is an extra 80-100lbs. But in street trim its 2700lbs. 2600lbs is no driver.

 

Sure thing. Wheels are VMS Modulo 15x3.5 with hoosier 25x5x15 up front and 15x8 26x8x15 out back.

[DcrDavid]

Heres a video i threw together from the passes.

 

 

[Richard Oben]

Really cool holy cow that thing revs fast.  Nice work.  R