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JZA70 448 rwhp everyday
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2,994 Posts
Discussion Starter #1 (Edited)
Hey there, im gettin ready to dyno 15 psi and I would like some input as to what plug gap I should be running, and where my timing should be at. Stock CT-26. I live at sea level, and it will probably be in the 60 - 70 degree range outside. Mods.

1. 3" Down Pipe
2. 3" Exhaust
3. Lexus AFM
4. 550cc injectors
5. Blow off valve
6. Hard pipes
7. Spec stage 3 Clutch
8. Bost Gauge
9. Profec A Boost Controller
10. AEM Wide Band o2 with gauge
11. HKS MHG
12. ARP head studs
 

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JZA70 448 rwhp everyday
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2,994 Posts
Discussion Starter #4 (Edited)
.032 is stock IIRC, so im already set there, and my timing is set at 10 which is stock. At what PSI would i wanna start making my plug gap shorter, and my timing adjustment?

~scott
 

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Republican
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8,421 Posts
You dont ever adjust your timing. leave it at 10. You might want to put it to .30 or .28 since the car was missfiring a lil under boost.
 

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JZA70 448 rwhp everyday
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2,994 Posts
Discussion Starter #6
When i drove to work today it wasnt missing at all, that was at 13 psi. my AF was mid 11s w00t.

~scott
 

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Republican
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cool... so why did you ask the question then?
 

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JZA70 448 rwhp everyday
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Discussion Starter #8
Because I was curious what people with more dyno experience sugguest. I'm surprised that people leave the stock timing, I was hoping for some more insite on that issue specifically.

~scott
 

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Be original, not a copy
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861 Posts
You can bump it up to 12 BTDC with no issues and slightly better off throttle response. Anything above 17psi (if you don't hit fuel cut first) will probably not yield you too much with the stock CT. What intercooler are you using? I'm heading over to the dyno in an hour or so to see how much of a difference the R154 makes. I recently backed up 487 RWHP (one 490 run and one 487 run again) with the A340. Switched the trans in the car to do some "work" on the A340. Everything else is the same on the car. It is a comparable temp and hummidity today so the comparison should be good.
 

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JZA70 448 rwhp everyday
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Discussion Starter #10
stock intercooler

~scott
 
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I had my timing set to 12 btdc and the response was a little better but on some days it would cause knock as boost hit so the ECU would retard the timing a boatload and Id lose power overall. I did notice that when I ran race gas, the car would run better too....

I have an Apex ITC to install this summer so I can turn my base back down to 10 btdc and then ramp it up in the lower RPM.

Bring a timing light to the dyno and change your timing from 10 btdc to 12 btdc and tell us if theres a power diff. :)
 

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.032 gap should be ok for that boost level, since our stock ignition is prettyy good. I always make sure I have fresh sparkplugs before I dyno. And I would leave the timing on the stock setting of 10 if you are not going to run any race gas.

Seems like you have some nice supporting mods. You are definantly ready for a turbo upgrade since it will be your biggest bang for the buck.
 

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JZA70 448 rwhp everyday
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2,994 Posts
Discussion Starter #13
Thats my next move, but I wanna wait untill I have funds to complete the full turbo upgrade. I'll give u guys a hint t04R. As of now i have a tial 38mm Wg, and a t04B core. I still need a T4 manifold, DP, and lines.

~scott
 

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Be original, not a copy
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Silver88Turbo said:
I had my timing set to 12 btdc and the response was a little better but on some days it would cause knock as boost hit so the ECU would retard the timing a boatload and Id lose power overall. I did notice that when I ran race gas, the car would run better too....

I have an Apex ITC to install this summer so I can turn my base back down to 10 btdc and then ramp it up in the lower RPM.

Bring a timing light to the dyno and change your timing from 10 btdc to 12 btdc and tell us if theres a power diff. :)
Odd that you had knock with that small of an increase. I pick up slight detonation when running pump gas and 20psi on the street with 12BTDC but none on the dyno. I probably have a few more supporting mods though. The spool is quicker with the 12 initial and the curve is a bit broader but if you are getting detonation then it is a bad thing to do.

Anyhow, I'll post the sheets up later but there is about a 3% improvement in power with the R154 over the A340, albeit 200rpm later than the previous peak of 487. Broke 500RWHP and all it took was a transmission change, LOL.
 

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JZA70 448 rwhp everyday
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2,994 Posts
Discussion Starter #15
Nice numbers Dean! I'll probably adjust my timing at the dyno as an experiment. Ill post results later next week, as long as Ckanderson can get his damn 38 lbs/ft of TQ 1jz ready in time!!

~scott
 

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scottiedawg66 said:
Thats my next move, but I wanna wait untill I have funds to complete the full turbo upgrade. I'll give u guys a hint t04R. As of now i have a tial 38mm Wg, and a t04B core. I still need a T4 manifold, DP, and lines.

~scott
And a bigger wastegate.
 
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DeanMarcum said:
Odd that you had knock with that small of an increase. I pick up slight detonation when running pump gas and 20psi on the street with 12BTDC but none on the dyno. I probably have a few more supporting mods though. The spool is quicker with the 12 initial and the curve is a bit broader but if you are getting detonation then it is a bad thing to do.

Anyhow, I'll post the sheets up later but there is about a 3% improvement in power with the R154 over the A340, albeit 200rpm later than the previous peak of 487. Broke 500RWHP and all it took was a transmission change, LOL.
Yea I ran my car on the street with that setup and I would only get knock every once in a while.....maybe like 3 or four times over the summer. Not a big deal but thats why I got the ITC. The response should be great with a 16* btdc base setting off boost. :)

Nice #'s btw. :bigthumb: What turbo?
 

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JZA70 448 rwhp everyday
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2,994 Posts
Discussion Starter #18 (Edited)
Ckanderson said:
And a bigger wastegate.

i think a tial 38mm would work fine for 19 psi with a .81 ar turbine, and 66mm compressor wheel.

~scott
 

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Just some guy
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Here's what you can expect from a 10 degree to 12 degree change. Runs 1 and 2 were at 12, run 3 was at 10. Barely any difference at all. Done @5psi boost.

 

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Be original, not a copy
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Silver88Turbo said:
Yea I ran my car on the street with that setup and I would only get knock every once in a while.....maybe like 3 or four times over the summer. Not a big deal but thats why I got the ITC. The response should be great with a 16* btdc base setting off boost. :)

Nice #'s btw. :bigthumb: What turbo?
Custom ITS piece. Very happy with it. "One of a kind". If it ever blows up I will probably go with a SP.
I've never really seen an improvement with anything over 14BTDC and would often get a "stumble" on tip in when running 14+. Have you tried running it that high? I ran 12base when I was using the HKS EGC on my first N/A+turbo setup and it ran fantastic. Lots of power to be found with ignition curve manipulation but too much base timing causes funky stuff to happen.
 
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