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Discussion Starter · #61 ·
Well I ordered some IK27 plugs (now 24), and hotwire coil kit, and if I will have spark blowout at 20-23psi than I will go with DLI....

What about actuators guys, I know almost everybody change them to Forge or Kinugawa, but is it must to change them for 20-23psi or not?
 

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Discussion Starter · #63 ·
Bump for wastegate actuators? Should I leave it stock or change them for aftermarkets....for 20-23psi?
 

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You should read some build threads dating back 5-8 years. You'll see that a lot of these questions have been covered in them by trial and error of other 3S owners.

Stock wastegate actuators are fine up to at least 25 psi if you upgrade to better boost solenoid such as the Tactrix one.
 

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Discussion Starter · #65 ·
Believe me, that I read all the time about dr750 builds, just sometimes I am not clear so I ask here (again).

Never hear od Tatrix boost solenoid, but I have Blitz SBC ID boost controller, with their blitz solenoid. Or we are talking something different?

From reading dr 750 build, I am also worried about pressure pulsing... I have big side mounts and hard pipes, and have little pressure pulsing now with 15g, so with dr750 I guess I will become even more ...

Do you have pressure pulllsing while driving your car?
 

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750's are one of the most notorious turbos for compressor surge (pulsing). There are a few band aid techniques used to reduce/minimize the surge. Snakeskinner liked adjusting cam timing. Ray P used a balance tube. Some guys use a weak bov spring to effectively hang the BOV open at light engine loads. Some say oohnoo side mounts corrected it. I put some air bypass solenoids on my car to help. In the end, how you choose to combat the issue is up to you. You will likely have the issue though. Some cars it's more pronounced and others it's tolerable to deal with by simply adjusting driving technique.

Jeff
 

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Discussion Starter · #67 ·
I guess I wlll first try as it is, if wont be drivable I will try Snakeskinner and adjust cam timing. Next thing I will mount back stock turbo bubble pipe and then also play with BOV.
If this wont help then I will need your help with air bypass solenoid :)

What about If I put back high flow catalic converter, would that change anything (like backpressure)??

I just hope, I will like them more than 15g.
 

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Discussion Starter · #69 ·
I have surge (pressure puls) on 15g, but car is normaly drivable and I dont feel it, you just hear chu chu chu on highway when road go little up, and boost is around 0-3psi...

I dont know which big side mount I have, but I bought it 15 years ago from 3sx.... anyone know what they were selling that time ? I know It was complete kit with dnp pipe...
 

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Discussion Starter · #70 ·
I finally resolve my 3-6 ignition problem, so now I have to resolve my next problem before I install dr750.
I found that I had drop in fuel pressure, from 40 to 20psi.....so I change for new FPR (not adjustable). Now what I see is when car is cold pressure is round 40psi, and after car is warmed up, pressure drops to 35-37psi. Is that normal or not. (supra pump + hotwire) ?
 

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It's most likely not the fuel pressure changing but rather the fluid and air inside the fuel pressure gauge expanding. Check if your gauge has a small rubber plug you can pull out to relive the pressure inside in the gauge. I have to do that on my gauge to get a correct reading.
 

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Discussion Starter · #72 ·
Yes, I have black rubber plug in my gauge. And It has bubble inside, and you can see that oil expand, as air bubble is smaller when car is hot...
 

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Discussion Starter · #73 ·
Next: My plan is hotwire Coils. Is there anything I have to be worried? (Bought hotwire kit from NinjaP).
 

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Discussion Starter · #74 · (Edited)
Ok guys, first drive with new turbos...I am just happy that the build is done. For now. I drove 60miles and it was pleasure.
What I change is dr 750 turbos, hibrid 2pc driveshaft and plugs ik27 and new fuel filter. At the moment it is on low boost 10 to 11psi kinugawa wastegate. Map on safc is stil old for 15g and 550cc and 18psi pump gas

impression:
Well, car drives with new drive shaft and new shaft bearing very very smoth. I can not say that it will give you hp but car drives really smooth.
For turbo...I really cant say anything , because at 10psi you just can not say anything. Tubos have little different sound and car moves, no question. What I notice is maybe few rpm laggier than 15g. But that is just maybe, because I am use to have 18psi and kick in the butt. Because it is still on old map, when you floor it, there is some black smoke going from exhaust. I wasnt on higway so I could not wach my wideband bit must be 10:1 or lower... On close loop car drive 14,7 to 15,2af.

What I have to do first is fix all boost leaks. And I think I have also exhaust leak somewhere. Check for Ptu connections, because I have also problem with 3_6 spark....sometimes

Then I will change maf for dr arc2 and install snowperformace stage 2. Then we will see what hp will get from this setup. In the near future, I wil also change injectors from 550 to 660cc.
Regards Jaka
 

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Discussion Starter · #75 ·
Ok guys, today was dyno day with new dr750.
Well ...my numbers are not good at all.., but I had boost leak.
390awhp at 20psi....

20psi was peak at around 3500-4000rpm, and then dropped down., so there is no real numbers.

Now I have to fix those boost leaks, and install methanol injection...
Still only on safc and sitc.... colder plugs and hotwire plugs...

I wished I would get more hp, but I hope that boost leak is the main factor....

What I noticed that boost gauge ( AEM) at that moment (3,5-4k rpm) just dropped down to 0 , but on boost controller looked fine...

What do you guys think?
I guess I suck, because I did not checked for boost leaks before.....
 

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1G Foglights b!tches
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Based on dyno graph it doesn’t look like boost is dropping since HP is climbing with rpm.

Dyno is a tuning tool. Doesn’t really matter what it spits out for HP. Might be meaningless to compare to others.

Do you have a lot you could post or post a screenshot of log?
 
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Discussion Starter · #77 ·
No, I dont have logs, I really need to check my boost leaks, just dont have time... Here is HP vs Torque ( crank hp.....I dont know how he calculate hp loss but it looks like 10% loss).
If you look blue ( torque) and dark red (HP) line, you can see drop between 4k and 4,5k rpm. I guess there is boost leak....
 

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Discussion Starter · #78 ·
What I did is put gain in boost controller to 0, so that is why turbos spools slower I think. But I did this to be little safer on block.
 

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Discussion Starter · #79 ·
And I retardered timing for 7 degres from 5000rpm to 7000 on SITC:..
 

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You shouldn’t have to retard the timing especially since you’re on 550s and not 660s or above. Your injector duty cycle will be higher and ecu load 200+ to hit the 21 degree WOT higher rpm factory map so pulling 7 degrees shouldn’t be necessary. Depending on how much volume of w/m you spray, you could compensate for another 100+whp of fuel over the 550whp the injectors are capable of, but you won’t want to go that high 28-30 psi on a stock lower end.

You also made 414awhp on 15Gs with 2 less psi so there is definitely something wrong. Definitely get your boost leaks fixed and add some timing back in. If you want it to be safe you could always pull some timing around 3-4.5k since that’s usually the hardest torque hit from full spool but up top I wouldn’t pull any.

It’s pretty easy to boost leak test and doesn’t take much time at all. Make a little adapter that fits into the stock air bubble, block off the lower intake manifold vacuum hose, block off the rear valve cover vent to the bubble, and block off the vacuum line to the boost controller if it leaks out the vent. Fix any leaks you find and then you can further test the pressure side by capping off the y-pipe right before the TB. You shouldn’t have any pressure drop at that point whereas you’ll lose a little air through the valves when you are pressurizing the whole system with the upper and lower intake involved.
 
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