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-   -   12a CarTech drawthrough HELP!! (https://www.rx7club.com/1st-generation-specific-1979-1985-18/12a-cartech-drawthrough-help-814461/)

TwistedOne 01-25-09 01:34 PM

http://i17.photobucket.com/albums/b9...06002Large.jpg

http://i17.photobucket.com/albums/b9...06003Large.jpg

Bearzah 01-26-09 09:41 AM

wicked bug. What year is it? That car would look awesome with a 13rew stuffed in it.

Bearzah 01-27-09 01:04 PM

WTB Used Wideband
 
Hey guys.. I've realized if im gonna try to push anything past 6-7psi, it would be best if I was running a wideband AFR gauge.

Does anyone maybe have a used one they would sell? If so, please PM me with pics and info. Thanks

If I do get my hands on a wideband... seems installing about 3 feet behind turbo is the norm. Any installation suggestions?

PercentSevenC 01-27-09 01:58 PM

If you're a DIY type, you may want to check this out:
http://www.14point7.com/JAW/JAW.htm

I bought a kit from there, but I haven't gotten around to assembling it yet. Seems those who've used it have mostly good things to say about it.

Bearzah 01-28-09 09:38 AM

well, the idea of spending ANOTHER $300+ for a guage is leaving a sour taste in my mouth as I already have a narrowband afr gauge laying around.

I know a wideband afr will burn up if to hot... thus the 2-3' mounting after the turbo.

But, I remember reading a narrowband NEEDS heat. Where is the best place to mount a narrowband sensor? Just a few inches behind the turbo?

Any recommendations on narrowband sensor itself?

Thanks guys

RXvedub 01-28-09 09:49 AM

no more than 14" from the turbo downpipe. also make sure to mount the sensor on the top side of the pipe. oh and $300 is much cheaper than a blown motor !

yetterben 01-28-09 09:56 AM

this is gonna be the shortest lived turbo ever. Spend the money or dont do it at all.

Bearzah 01-28-09 10:32 AM

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yeah... buying a wideband RIGHT now.

prob gonna go with the AEM for the "needle" and digital readout... cough and price cough

Any1 have bad things to say about the AEM Wideband UEGO Controller Air/Fuel Ratio Gauges P/N AEM 30-4100

http://store.summitracing.com/partde...5&autoview=sku

yetterben 01-28-09 10:42 AM

Mine works like a dream

justint5387 01-28-09 10:52 AM

The AEM is good, i am using it now

RXvedub 01-28-09 11:15 AM


Originally Posted by beargogerrr (Post 8918154)
yeah... buying a wideband RIGHT now.

prob gonna go with the AEM for the "needle" and digital readout... cough and price cough

Any1 have bad things to say about the AEM Wideband UEGO Controller Air/Fuel Ratio Gauges P/N AEM 30-4100

http://store.summitracing.com/partde...5&autoview=sku

thats the best price for a quality unit, get it!

Hyper4mance2k 01-28-09 01:01 PM

Widebands are great for WOT tuning, but they don't react to spikes like a narrow band will. Like in my application I used to get a lean spike on cruise and the wideband doesn't see it at all, but the narrow band does. I run the atuometer procomp ultralight wideband and narrowband.

justint5387 01-28-09 01:58 PM


Originally Posted by RXvedub (Post 8918288)
thats the best price for a quality unit, get it!

I believe a seller on ebay sells the UEGO for $205 shipped.

vxturboxv 01-30-09 02:06 PM

I've got a suggestion or 2! Nice car BTW....

Anyway I don't agree with only 10* of advance for starters..... I also don't agree with trailing spark on turbo/N20 applications.... Or disabling the vac advance....But hey that’s just me.

I think 10* is working for everyone because they are splitting there combustion cycle time between the 2 (L&T) IGN phases. This does seems to work ok… It’s just not as efficient as one big bang IMO. Also this means that as your cruising your timing is at 10* all the time.... This results in crappy MPG and drivability. Why not make it work more like it should?

Heres what I'd do... ;)

"T" 2 new leads from the wires powering the leading coil. Remove the orig. wires powering your trailing coil. They aren't used anymore,set them aside. Connect the T'd wires from the leading coil to the secondary coil. Doing this will disable the trailing spark and gives you one simple timing number.

Set base timing to 15*. (I like around 18*, see meth injection below)

Then install 3 or so 1-way aquarium check valve bleeders inline with vac advance on the distrib. This will allow vacc and not allow boost into the advance diaphragm. So during idle and cruise conditions you will have your timing advance. As you go into boost all the press/vac will be lost out the check valves,bringing you back to your base 15* timing.

Similar to this pic. It's cheap (under $10) and works very well....

http://www.gotrice.com/turbopics/temp006.jpg

Then instead of an IC I'd run a simple DIY methanol kit. This way instead of farting with carb. jets all the time, you can just adjust the amount of methanol you spray. It will cool the charge and fight off detonation at the same time. You can easily run 18* total timing and 10lbs of boost w/ the methanol injection setup.

All my suggestions are cheap and easy.... and will make a night and day difference on the way the car performs.

That little t-25 is gonna spool up REALLY fast! :lol: IMO a t-25 is too small of a turbo. It will choke the exhaust pulses. Ever notice how huge a stock TII turbo is for a 1.3 litre? I suggest a .63 rear housing and a 50 trim turbo of some sort. Stock grand national turbos are close to perfect. Also TII turbos work very well.



Good luck!


Bring on the flamin' :lol:

Bearzah 01-30-09 05:44 PM

I can see how the one way check valve might work... That is IF i wasnt using a drawthrough setup... I would have to install something on the pressure side for that to work. Although... Setting leading and trailing to fire together sounds like an idea. Has anyone tried this success?

Bearzah 01-30-09 07:19 PM

turbo info
 
So I cleaned up the turbo and got some part numbers off it, but, I'm finding it fairly difficult to find information on them. I've searched this forum and google.

It's an Ishikawajima-Harima Heavy Industry RHB6, serial # B6017759, spec V C 8. On the exhaust housing I can make out:
...... PZ
20.. -R
(the periods are just for spacing to show arrangement of letters/numbers)

The carb is a Holley list - 8007 (with 1113 under that). I think thats a 390cfm carb. The vac secondary pot is disconnected and linkage modified to work as mech secondaries.

From what little I've found, it appears to be similar to a Hitachi IHI-T3 or IHI-RHB6 T3 turbo. Its looking like it will reach max boost fairly quickly.

Any experiences with these turbos?

Anyone know where to find some info on it?

Thanks Guys

Bearzah 01-30-09 10:50 PM

4 Attachment(s)
OK... here are some pics of my project I will be starting tomorrow.

yetterben 01-30-09 11:30 PM

Dude myself and others have been doing this for awhile. 10 is the safest bet. Don't fuck this dudes engine with your lack of turbo carb setup knowledge.

Bearzah 01-31-09 12:19 PM

hmmm... wastegate ISSUES!!!
 
2 Attachment(s)
Started by tearing into turbo to make sure everything turns/moves freely.
I found my exhaust/internal wastegate was almost seized. The vacuum pot moves freely with plenty of closing force. I removed the wastegate valve portion from the turbo and soaked it liberally with WD40.. see below.

I can get the valve to move, but, it's pretty stiff. I put in back on the turbo, connected the wastegate linkage, manually opened the valve and it wont close all the way or move much at all. GAH!!!!!

Looks like tearing apart this valve will be near impossible as valve/flap is welded to shaft and set pin for shaft has been center-punched to lock it into position.

Im looking for suggestions.

TwistedOne 01-31-09 01:45 PM

I would weld the valve closed, and run a tial 38mm valve with a 10 psi spring.. You could do a 15 psi spring and put a boost controller on it...

vxturboxv 01-31-09 02:05 PM

For a simple setup (which is what your doing) Just keep it simple. Get yourself some JB blaster and soak it in that for a while (day or so) and keep working it. It should eventually free up. I'd get a torch or heat gun and get it nice and hot while working it. Then if possible get a small container and let the whole assy. set in penetrating fluid. (JB blaster)

Worst case you can tap the rod out and install new bushings.


Originally Posted by yetterben (Post 8926122)
Dude myself and others have been doing this for awhile. 10 is the safest bet. Don't fuck this dudes engine with your lack of turbo carb setup knowledge.

Your incorrect. That's all there is to it. Anyone with even a little common sense would see that.

But I may be incorrect. Me an every auto manufacturer since the 1940's that has found adjusting there timing nets better MPG and performance. Turbo and NA cars alike.

Leaving timing set at 10* is moronic. It's 1940's technology. But I'm glad there are still some old school tuners out there. I like to whoop up on them... ;)

RXvedub 01-31-09 09:57 PM

any turbo setup, even the new fuel injected ones have an ignition curve under boost that retards timing -not advance. timing advance under boost= blown motor.
since he has a distributor unmodified it will advance up to 30 degrees . this is ok for n/a but death for a boosted application. lock the dist. set it at 10 and be done with it. the guru taught me as with a few others chiming in and you guys know who im talking abour cough 680 cough :)
meth injection is great idea for draw thru since you cant intercool it :)

Bearzah 01-31-09 10:52 PM

Progress!!!
 
2 Attachment(s)
OK... I was able to free up the swing valve for the wastegate.... what a pain in the a$$.
I ended up having to soak it in WD40 for several hours while almost constantly working the swing arm (Initial efforts actually required a hammer or long wrench just to move the swing arm). I also heated it up with a torch several times to try and free it a bit. My initial messing around with it bent the shaft of the valve a bit, but, was easily fixed. She opens and closes quite nicely now.

I didn't get that all put together until around 5pm today, but, still managed to get the exhaust manifold, vacuum side and pressure side intake manifolds and the turbo itself mounted today. Pics below.

Tomorrow I plan on plumbing in the oil feed line and oil return line, putting carb on, installing the boost gauge and fire her up... once I'm confident it runs ok I will lock the dizzy (set leading to 10* and trailing to TDC with vacuum pots disconnected), swap in my new fuel pump and filter, fab up the downpipe and connect it to my existing exhaust and install my wideband.... sigh.. than take her for a drive (conservatively as it still have 3/4 a tank of regular gas).

Wish me luck.

Bearzah 01-31-09 11:10 PM

I've recently been PMing someone who is reminding me the original CarTech installation instructions say "...Ignition timing should be set 2degrees retarded on the leading and trailing."
There is nothing about disconnecting the vacuum lines or locking the dizzy.
I just want to make it clear this is a DRAWTHROUGH setup... the carb will ALWAYS have vacuum, even when i'm running 17psi boost (just before the engine blows.. lol.. I will NOT be boosting that much).
Most of the AWESOME advice people are giving me seems to be coming from peeps with BLOWTHROUGH setups. LOL, just wants to make that clear.

vxturboxv 02-01-09 12:06 AM


Originally Posted by RXvedub (Post 8927869)
any turbo setup, even the new fuel injected ones have an ignition curve under boost that retards timing -not advance. timing advance under boost= blown motor.
since he has a distributor unmodified it will advance up to 30 degrees . this is ok for n/a but death for a boosted application. lock the dist. set it at 10 and be done with it. the guru taught me as with a few others chiming in and you guys know who im talking abour cough 680 cough :)
meth injection is great idea for draw thru since you cant intercool it :)

I disagree....

Yes as said, he should remove the springs on the fly weights. So as soon as the car starts the fly weights will lock out at full max mech. adv.

Anyway all I'm saying is the more timing U have, without detonation, the more power U will make. Esp. with a low boost application. (like is being done here) 8lbs of boost @ 15* of timing is still conservative. But it will make more power than 10* of timing @ 8lbs. So why not run more timing?

Personally I run 25lbs through a t-68 @ 25* timing. This is all on 91 octane fuel with meth injection.


Keeping your timing locked @ 10* is a total waste. You lose max power and cruise MPG. Esp. when not running much boost.


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