[Dynospeed]

Originally Posted by americanmusc1e

Wow! thanks for all the responses. I've figured out a few things so far:

1. I missed the fire ring when assembling the wastegate i've since fixed this. It has definitely helped with spooling the turbo. I start building boost around 3500rpm now and I can hit 5psi between 3800 and 4200 on the street now.

2. I figured out a manual boost control setup and i'm running ~12psi now. This will do nothing for my launch, but it should help on the top end.

3. I switched to a real cam that is known to work well with turbo applications.Sloppy Stage 2. This gave me even more midrange, but I think i my converter may still be too small for the best dragstrip performance. There is still a turbo-less spot for the first 500rpm out of the hole.

4. I've learned a lot about turbos and found out that most single turbo LS guys are using a turbo based on a T4 exhaust housing. My turbo is only 69mm, but it uses the larger T6 housing and fairly heavy internals. This has a lot to do with how slow mine spools up. For around $400 and some exhaust work, I can upgrade to this which should help my spool a lot.

5. I've talked with some guys running T6 turbos and I'm going to add some timing in the <5psi zone to try to get it to spool faster.











I currently have no boost until i'm out of my 60ft. That's why it sucks so bad

No transbrake. I built the Th400 myself so I could probably figure out how to add one.

The ECM is a Megasqirt MS2 which will do 2-step, but not while controlling a v8. I'd have to step up to a MS3 which is another grand.



currently i haven't seen any boost below 3500. My converter won't budge past 3000. On the street I'll start spinning the rear if I try to hold it with the brakes.

Wrapping the crossover pipe is in the plans for this week. my dipstick tube was leaking and i wanted to fix that first. I don't want oil on my wrap. The manifolds are very thick (cast iron and schedule 40). They should retain heat well.

Out of the turbo I'm 3.5" exhaust dumping just after the cab. The only muffler I have is a 8" glasspack that's 3.5" all the way through.

Get a transbrake as your next item. Sometime measure the inducer and exducer on your turbo. You may not want to put any $$ into your current turbo depending on what you have exactly. Also depending on what the max power you looking for is a 7675 will come on very quickly and works well on a 5.3 but its a small turbine for a 6.0 and bigger. If you have bigger plans that 850 flywheel I would go T6 Borg Warner 75-80mm with a 96mm turbine. Then on the converter PTC is our normal go to. I just spend a decent chunk of money for ya but you are now into the 9's.