Slow spool wih 6152 turbo

[GNVYUS 1]

Fill us in on fueling and what Rpm you're seeing 0psi-1psi?

If you have a Wideband that would help to see what AF/R you're at while brake torquing even if the converter is tight.

BTW, the Precisions need to be locked at WOT in 3rd to be efficient, otherwise I've yet to see a L/U break into the single digit % efficiency wise unlocked.

 

[dvernst]

That was locked. It locks at 80 MPH...

 

[Dusty Bradford]

I thought the 6152 journal needed atleast 3200 @ 1 psi with the converter you are using. Prolly needs more like 3400 @ 1 psi. lol

You can spool that turbo with a 2800 stall at 0-1#.

 

[Slow91z]

You can spool that turbo with a 2800 stall at 0-1#.

Definitely true, I had a totally stock long block T with that turbo and a Bradco converter that stalled very close to that and it was an animal. Ran a best of 7.0x in the 1/8th on pump gas/alky.

 

[dvernst]

1

 

[dvernst]

This is a run from the street.

 

[dvernst]

This is from the track.

 

[dvernst]

Anything look abnormal to you guys?

 

[Slow91z]

Ok I just got done looking at your logs, I saw nothing "wrong". 1st thing I noticed is that you said that you could only make 2700-2800 RPM brake boosting, but according to the log you were at 4000 RPM at 0-1 MPH and 14 psi, also at 1 psi you were at 2800 so I'd say your converter is pretty good for your combo. I did see a tickle of knock in a couple of places with no clear reason for it I saw, it wasn't on a shift or anything so I'd say it warrants further investigation on your part.

On a stock long block car such as yours I would like to see more timing, at the end of the track it's all the way down to 16.6*. On the conservative side I would be running more like 22 at the end and closer to 25 out of the hole, that should pick up your 60' times. With 100 octane you might have to back the boost down some to accomplish this (I don't know for sure how much 100 can take), but I'm pretty confident it'll go faster with more timing and bit less boost than it does with almost no timing like you have now.

 

[dvernst]

What about the full 2 seconds it takes to build boost? Also i'm definitely moving before the log shows i'm moving. I'm not lying, or missing something about what I told you. This is a new turbo, so I have my old one to compare it to. It spools so slow I would rather have my ta49 back. Thanks.

 

[Slow91z]

I don't think you're lying, but i find it hard to believe that you are moving before it shows 1 MPH...Is the MPH right when you are driving down the road?? All I know is my car worked well with a stock motor and a 6152, on pump gas/alky it ran a best of 7.0x in the 1/8th mile with a 1.47 60' (30 psi, and I don't remember the timing, but much more than yours.). Converter was similar to yours during spool-up, and it came on HARD. Double and Triple check your wastegate/exhaust leaks/boost leaks/etc. because it shouldn't be as bad as you describe with that converter.

 

[dvernst]

I started moving when the tps was about 2.4 volts. I trapped about 114.xx on this run. I think the log shows 108...

 

[BEATAV8]

vehicle speed signal is heavily filtered. it doesn't show your moving until well afterwards.

 

[BEATAV8]

Vern I didn't realize you were locking the TC... (cheater!)

That baby is slipping about 11% despite being locked.

 

[Sweet6]

I am kind of leaning towards exhaust leak too. I had no problem spooling a 63E with that same converter. I would get low 1.6X 60fts launching at 5-6lbs.

 

[BEATAV8]

Vern,
which wideband setting do you use on your powerlogger? I have it set for LC1 and it's showing the car is at 10.7:1, I thougt it was running in the mid-low elevens for AFR?

 

[dvernst]

View attachment turbo TA 100oct.005.zip

Here's another run. I pulled some fuel...

 

[Sweet6]

Or fueling. I usually have to take a lot of fuel out of my TTA to get it to 60ft for some reason. But I am also using an Alky kit. So it takes some tweaking. What is your fuel pressure at?

 

[dvernst]

42-44 psi Line off. It should be in the log. Actual pressure is 2psi higher than the transducer

 

[Sweet6]

I have mine down to 38 and it likes it so far.