im running 60-1 with a .96AR turbine on a streetport. tial 38mm wastegate. this log is with boost controller off.

https://www.rx7club.com/showpost.php...55&postcount=8

i have a greddy profec b, would using the controller inxrease boost response?

 

Gotta give more details on your setup. If you're running an old engine, log exhaust manifold, 3" exahust with a cat that looks about right to me.

 

I had a very similar boost curve with FC HKS log mani, HKS 40mm gate, and T04S 60-1 with p trim .96 hotside. I ended up going with a divided stainless manifold and larger wastegate.

 

o sorry its a 3" dual exhaust, no cat. rebuilt engine with like 3k miles on it.
older fd manifold

 

get a divided 1.00 A/r turbine housing to match your divided manifold. It may help some.

 

wont the bigger AR housing make it slower?

 

divided helps a lot, if you have a divided manifold. And the turbine trim changes a lot as well. P-trims usually run larger housing.

I run a 1.15 P divided, and it has moderate, but very smooth and controllable boost. But I do plan to move up to a 1.00 P.

 

my manifold is divided as u see but the turbo isnt.

 

It doesn't seem THAT bad. You most likely have a few small exhaust leaks. I have the same turbo as you but .84 A/R. You really can't expect tons of boost anywhere below 4k. If I have the smallest exhaust leak, and or my 38mm wastegate with a 5 lb spring is being pushed open, it is noticeably slower. In the morning, when the gate stays shut, nice unheat soaked AIT, the boost hits much sooner, and much harder. I even have a slight problem with boost spike it hits so much harder. (tuned my haltech boost controller off when its warm and calmer. New tons better boost controller needs to be installed, should fix any problems.)

I say, make sure you turn is awesome, check your EGTs, and get an EBC on there. I had tons of little exhaust leaks, (between turbo and manifold, manifold and engine, manifold and WG), I had to put soapy water all over my turbo / manifold and put pressurized air in my tailpipe to find the leaks. Tons of bubbles.

Little things really do make a difference. The slightest leak acts like your wastegate is open. Our turbos are not t04e, or BB or anything, there is going to be a little lag. Consider it traction control. Mine is divided turbo, I'm sure my divided, and smaller A/R help. I really am thinking about going up an AR though.

Hope that helps.
~Tweak

P.S. WHATS UP WITH YOUR RPM?!?! Its all over the place. O.o

 

well i think i have a leak between turbo and downpipe.
im not really sure what psi spring i have either, i pulled it out and it had no color im thinking of getting maybe a 10 psi spring then using ebc to bring it up to 15. right now ebc is off.

 

Judging by how fast your boost shot past 10 psi, it slowed down around 14 psi, I would say you have something more close to 13 or 14 psi, not 10. Even with EBC you can't lower your boost past the spring.

 

ya no i meant i WANT to replace this current spring (which i think is 14pso as well )to a 10 psi one.
ya bdc told me to check my gain settings for rpms.

 

my old turbo which was around the size of a t60-1 would spool up to 15 psi around 4k without the ebc and somewhere around 3600rpm with the EBC tuned. This is with a divided mani, undivided .84 housing, 50mm hks open vented gate, and 3" exhaust on street ported engine.

My new turbo is a masterpower t70 with .96 undivided housing. it reaches 15 psi by around 4.5-5k with the ebc on, everything else is the same. The whole turbo CHRA is heavier, so i'm sure some of the spool loss is due to this and partly due to the larger exhaust housing. I'll probably try to get a divided housing sometime to help it spool, maybe go with a 4" dp also.

your setup does seem to be quite sluggish for a t60-1. I think you should be getting 15 psi by at least 4.5 k especially with a street ported engine

 

Check for leaks.

Start it up stone cold, and quickly feel around the manifold to engine flange, turbo to manifold flange and wastegate to manifold flange.

Those are the most vital areas to seal for spool up. An exhaust leak post turbine isn't going to make it spool slower.

Also, check for boost leaks, its possible there's a teency one somewhere.

Seems a little laggy to me, but there's *alot* of variables.

 

This isn't intended as a threadjack, but on my old setup I always thought I had an exhaust leak I couldn't trace down. Were you pressurizing from the actual tailpipe itself? Or pressurizing from the intake ( the normal way) and feeling for exhaust leaks from around the turbo manifold area?

I am building a new motor right now and I want to see if I can locate any exhaust leaks while it's still on the engine stand. So I was going to hold the TB butterflys open and pressurize from there. Do you think that would locate any leaks from turbo-to-manifold or manifold-to-engine? Or maybe I could throw a pressure tester on the vband section of the turbine housing? I just don't want to deal with that bullshit with the motor in the car if possible.

 

+1. These exhaust leaks are more common than may seem to be.

B

 

ya ill have to do that then, i know for sure my vband Between downpipe and turbo is leaking.

 

that shouldnt really effect the spool since its after the turbo, unless it can somehow disrupt the flow, but i doubt it would have much of an impact

 

any exhaust leak will slow spool from my experience. I had an o2 bung plug come out (at the back of the downpipe) when I was on my stock turbo and i could feel a loss of response.

 

i would run a smaller .86 or something similar , i used to run both the .96 and a .84(or .86) cant remember , the smaller housing i used to run around 14/15 psi , response was great , and the larger housing i used when i was running slightly higher boost , around 20/22 psi , felt a bit slower response but top end was greatly improved with then
at least , ...for me

 

that's odd, i would think anything after the turbo would have little effect. maybe the exhaust gets jumbled up and doesnt flow smoothly. Was it a significant loss in response? Has the OP checked for leaks yet?? any update?

 

Best solution would be a divided turbine housing to match the manifold. A friend of mind has a .96 divided he may sell.

Barry

 

you must hav a leak somewheres