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Resident Smartass
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Discussion Starter · #1 ·
Just finished the swap in my 1jz MKIII, Took it to a local 1/8mile track to test it out. I have a 4000 stall and was shooting a 170shot off the line on 26X10.5X15 et streets. I got to make 2 passes and my best 60ft was only a 1.88. :wtflol: What the hell did I do wrong, I was expecting low 1.60's high 1.50's out of it. I wasn't using the transbrake. I stood on the gas and brake-boosted to around 6-7psi and then launched on the N2O. I did an ample burnout before each pass. Any tips/suggestions.. All mods are in the sig. Thanks in advance Oh yeah, the car went 7.68 on 18-19psi.
 

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its a slow auto...
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why are you using a 170 shot off the line with a 4k stall and a 67mm turbo? are the 1jz"s dogs compared to the 2jz? with my 2jz with a pt67 .68 ar i come out at 36-3800 with anywhere from 6-14psi using the foot and ebrake, since i dont have a transbrake.. also, all it say in your sig is safc? thats all your using to control your fuel? and how much boost are you running? i would think if the cars not spinning then your probably making that converter go way past its 4k stall with that 170 shot...unless you had them set the stall knowing you would be running a 170 shot on top of boost out of the hole..

jay
 

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jwcatto said:
Just finished the swap in my 1jz MKIII, Took it to a local 1/8mile track to test it out. I have a 4000 stall and was shooting a 170shot off the line on 26X10.5X15 et streets. I got to make 2 passes and my best 60ft was only a 1.88. :wtflol: What the hell did I do wrong, I was expecting low 1.60's high 1.50's out of it. I wasn't using the transbrake. I stood on the gas and brake-boosted to around 6-7psi and then launched on the N2O. I did an ample burnout before each pass. Any tips/suggestions.. All mods are in the sig. Thanks in advance Oh yeah, the car went 7.68 on 18-19psi.

Sounds to me like it was spinning. I wouldn't engage the N20 until you know the car is hooking. If your track prep is anything like out here that would be after the 1/8th mile. :)
 

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Resident Smartass
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Discussion Starter · #5 ·
Great questions guys: Jay: I don't quite understand your statement about going past the 4000 stall. I figured the bigger the shot the quicker it would spool (instantly by the way) and come off the line, also I have the .81 rear AR. Yes I am using a safc2 to control fuel and on pump gas 18-19psi it went 7.68. I run a max psi of 26 on c-16, and to be honest the safc2 works great. I monitor AF with the Innovate Wideband. So do you think I should drop down to a 70 shot? Also, the car hooked great on the first pass and pulled the 1.88 60 ft. On the second pass it spun as soon as I hit it, so I let off and whacked it back and still went 1.89 60 ft. As ya'll can tell, I'm pretty new to the whole "Drag" game. All help is greatly appreciated. I am going to tune on 26psi and a 70 shot the whole way through and I hope to go into the 6's in the 1/8th and mid 10's in the 1/4.
Thanks
Catto
 

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Not your average auto mk3
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I honestly think youre trying too many variables on your first passes. I think you should do passes on boost only to get used to launching the car, and getting her down the track. Practice launching off the footbrake before going to the transbrake. With the help of the ebrake, youd be suprised how much boost you can build. Play with tire pressures a bit. Once you can launch consistantly on boost, then start slow with the juice. Start at a 50 hit, then work your way up. Juice = torque = changes in stall speed.

I think you just dove in head first, and its overwhelming. Theres definitely a mid 1.5 60' to be had, and probably better since you have more power than i did when i was on stock suspension/irs setup.....good luck
 

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its a slow auto...
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Slow66 said:
I honestly think youre trying too many variables on your first passes. I think you should do passes on boost only to get used to launching the car, and getting her down the track. Practice launching off the footbrake before going to the transbrake. With the help of the ebrake, youd be suprised how much boost you can build. Play with tire pressures a bit. Once you can launch consistantly on boost, then start slow with the juice. Start at a 50 hit, then work your way up. Juice = torque = changes in stall speed.

I think you just dove in head first, and its overwhelming. Theres definitely a mid 1.5 60' to be had, and probably better since you have more power than i did when i was on stock suspension/irs setup.....good luck

i totally agree with this... to many variable at once..and if your positive its not spinning and still getting 1.8x 60fts then i would watch the rpms and i would bet your overpowering the converter and its slipping past it given stall speed..bring someone to the track with you and have them watch the car when you run to make sure your not spinning..


jay
 

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Hardtopper
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well, i may not be the best,.. but heres what im running
I also am going with a th350/400 75shot of not and a 67 .81 except im on a MKIV

But im gonna launch off the T Brake,.. and have the NOS set to WOT, I figure with my stall at 3500 i should only need to use 3/4 of my throttle to get it to that, then when i launch I will completly floor it thus car will already be in motion and tires will be hooked up.

Also if your worried baout accidently armong the nos while stalling, just run a relay switch and flip it once your outa the hole
 

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SF's Cleanest
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what track did you run it at?

are there any 1/4 miles in spartenburg?
 

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Resident Smartass
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Discussion Starter · #10 ·
Thanks for the info guys, I will give it a few runs w/o the N2O and see what happens. I made the passes at Greer and no there are no1/4mile tracks around, The closest is Atl. and I heard it was closing.

Back to the task at hand, I had 15psi in the et streets. When I sad I was fairly new to this game, I may have mislead you guys. I have been down the strip probably 50-60 times in this car, so I am used to the car and all. My question was on launching the th400 for the best 60ft. I've tried footbraking it and the most boost I can build is maybe 6-7psi, Not because the tires are spinning, thats all the boost it will build period. I am thinking I should have gotten the .68 rear ar instead of the .81, since the motor is only a 2.5l and it is completely stock. I hope to get back to the track next thursday and I will drop down to a 50 shot and see what happens,

Thanks for all of your responses,
Catto
 

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Not your average auto mk3
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I agree that the A/R is probably not helpign your launch issue, so the nitrous is a good way to solve that. Unfortunately, that increases the learning curve a bunch as far as gettign her down the track. Get a friend to video tape your launch to see if shees spinning, bogging, etc, as it is *sometimes* hard to know exactly what is going on in the drivers seat. Try lowering the tire pressure down to 11.5-12 psi( i found that works decent for me anyways). Also, if youre not already doing it, use the ebrake to see if you can build more boost (even though you said its not a spin issue, try it just for the sake of completely ruling it out)

It would also be a really good idea to keep a logbook of all the variabkles each run you make. Tire pressure, air temp, track temp, wind, boost, amount of nitrous, launch rpm, etc, so that you can see where improvements are being made. Also, dont make too many changes between runs, cuz then you may not know exactly where the gains are coming from. Anyways, like i said, good luck, and keep us clued in on the progress.
 

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Resident Smartass
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Discussion Starter · #12 ·
I taped the runs and have watched them several times. After watching them again, I noticed that on the 1st run the car moved about 3-4 ft before it took off. On the second run, the car spun instantly then hooked up. It spun on the initial hit, You know, when you nail it. After that, the car goes down the track flawlessly.. I am going to open a log book in my laptop and document the variables like you said. Thanks for the help, I am gonna run it next thursday and see what happens. Thanks again,
Catto
 

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Since a MKIII probably weighs 3600-3800 with driver and you are running a 2.5 1jz at 18-19 psi through a turbo 400 it is only making enough power to run 1.8 60fts...your rear wheel hp on boost alone on a 1jz at 18-19 psi is probably only in the 350-whp range max when running through a turbo 400 tranny as they have a very large parasitic loss. Add on the nitrous and you may be up to around 500whp max...it can really vary...all that combined with a heavy MarkIII may only yield you 1.8 60fts? Maybe crank up the boost to 30psi and up your stall to 4500-5000rpm and you can get that heavy beast off the line running some 1.6's or 1.5's... As a reference point, my 2jzgte T72 turbo'd truck below made 480whp at 18 psi through a powerglide, which launching off the transbrake at 5000rpm yielded 1.6 60fts and a 10.5 @ 133mph in a 2920 pound with driver vehicle...Your combination with the .5 lesser displacement, more parasitic transmission loss, 800 more pounds weight and lower stall speed I'd have to say 1.8's is probably exaxtly where you should be..If you look at other vehicles that run in the 7.8 range in the eigth(which translates into a high 11) They also run in the 1.7-1.9 60ft range... Check it out- http://list.to4r.com/ I'd say your 1.8 is right on target given your setup and 1/8 mile time...

Just my 02...

Dave
 

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Resident Smartass
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Discussion Starter · #14 ·
Damn thats a pretty good .02. Thanks for the info, You are probably right, On 18 psi the car is maybe making 350 through the TH400. I am going to get tuned on some 780cc injectors and get the boost to a max of 26psi( Stock ECU) and then we will see where we are at.
Catto
 

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its a slow auto...
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jwcatto said:
Damn thats a pretty good .02. Thanks for the info, You are probably right, On 18 psi the car is maybe making 350 through the TH400. I am going to get tuned on some 780cc injectors and get the boost to a max of 26psi( Stock ECU) and then we will see where we are at.
Catto

thats it, 350?.. i made 381rwhp through my th400 at 14 psi with my pt67 .68 ar...but this is with a 2jz......and running 19psi coming of the line at 7 psi i was cutting 1.60 60fts on 17 inch nittos..my car weighs 3750 plus lbs....
 

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Resident Smartass
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Discussion Starter · #16 ·
Yep, thats it, I am getting around 20hp per pound of boost. Motor is Bone stock, no cams, no nothing. Like I said, we'll see what happens.
 

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Not your average auto mk3
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I only made 406.1 whp at 18psi thru the th350, and 542 whp at 26psi. I shoulda ran it at the low boost setting to see what it woulda done, but what fun woudl that have been. Also, this was with a Turbonetics T61 .68 a/r, and i was able to launch at 14 psi, using the ebrake....1.57 60ft was the best out of my 3 launches on that setup. Your car will move ouot...just give it time :)
 

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jaynite said:
thats it, 350?.. i made 381rwhp through my th400 at 14 psi with my pt67 .68 ar...but this is with a 2jz......and running 19psi coming of the line at 7 psi i was cutting 1.60 60fts on 17 inch nittos..my car weighs 3750 plus lbs....
What do you mean, "thats it, 350?" You are comparing a 2jz to a 1jz...we are talking 30 cubic inches more you have! Even on a mild boosted motor making say 3hp per cubic you will have 90Hp more then a 1jz just due to displacement...Its not a valid comparison...Not to mention the torque factor which will be even more in favor of the 2jz's displacement advantage...

Just my 02

Dave
 

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Flying Dutchman Pilot!
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Damn thats one sexxy truck, got one just like it :)
 

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its a slow auto...
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turbodg said:
What do you mean, "thats it, 350?" You are comparing a 2jz to a 1jz...we are talking 30 cubic inches more you have! Even on a mild boosted motor making say 3hp per cubic you will have 90Hp more then a 1jz just due to displacement...Its not a valid comparison...Not to mention the torque factor which will be even more in favor of the 2jz's displacement advantage...

Just my 02

Dave

easy,easy..lol.. i was just surprised at the power level :stickpoke besides, he's running a 170 shot out of the hole, so who knows what it making when that on :dunno:

jay
 
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