Long story short, I did a custom TD61 journal bearing turbo build from Turblown. XS/HKS cast manifold, tial 44mm wastegate, 3.5 DP, HKS twin power, HKS EVC 4 boost controller.

The motor is healthy, there doesnt seem to be any boost/exhaust leaks.

After tuning for 15psi, the car put down 325whp. The car made 335whp at 13psi on the stock twins. The car feels really smooth and holds power all the way till 7000rpm but the power just isnt there. The worst part is that I dont see 15psi until 4500 rpm!!! Its is extremely laggy. In between shift it has to spool up again. I am not sure, but I feel like the lag is getting worse. It is 100F degrees today so I dont know if heat has anything to do with it.

Possibilities?
The AFR is at 10.7-11.0. So I doubt Im losing 100hp from that.
-Plugs will be changed with 10's but given the smooth power cruve I dont think the plugs are the culprit either..I have 9's right now.
-Leading coil-seems fine but there is a chance it may be going bad, again I dont think I would have such a smooth curve if the coil is acting up.

I have no idea whats causing the horrible spool time and power loss. I would expect 400whp with my setup at least with some decent response.

 

Dyno Graph:

The 345whp was a dyno run done before I re-routed the wastegate. So I lost about 20whp going from dump to re-routed which I dont mind given how loud it was before.

 

10.7-11.0:1 is certainly excess fuel.

You can make 11.5:1 mixtures work, and is a lot better. The figure is certainly low and I wouldn't be blaming the turbo. Its possibly in the tune or there is a flow choke somewhere such as a catalytic converter. In my experience I've had problems making more than about that power with a 4" body 200 cell catalytic.

What turbine housing do you have? I seem to remember Elliot suggesting the 1.15 T4 A/R? Because that is spot on for the engine.

Are you sure the boost is actually 15psi? I would be factoring 400-500hp depending on the dyno used. If your dyno includes the driveline loss correction factor (fudge factor haha) and times the power by 1.2 to guess flywheel brake horsepower I would be expecting closer to 480-500BHP!

I suggest you buy some R7420-9 for the leading holes and R7420-11 for the trailing holes.

 

The exhaust is 3.5' DP and 3 inch MP resonated 3 inch catback. So no choke bottle neck possible. When I tuned for the stock twins the AFR was the same and I still made 330whp. There is something majorly wrong. I will change the plugs for sure but again, I doubt it will solve the whole issue. My biggest worry is the turbo lag. Its unbearable and for a tubo this size it shouldnt. I forgot what A/R I have but elliot suggested it with RESPONSE in mind. It def has enough flow for the higher RPM range tho.

 

Do a compression check before you do any more tuning.

If that's ok, then it's either your tune or some kind of major exhaust leak.

9's are fine for plugs until you get into the high 400's.

 

Make sure the valve seat is in the wg and it's not leaking at idle. Any noticeable exh leaks? I'd also do a pressure test for any boost leaks

 

motor is healthy. Its the original motor but vacuum, compression is still good.

Tomorrow I will pressure test the system for boost leaks. It would make sense for a boost leak I think. The added work for the turbo to make 15psi will create more backpressure causing the relatively excessive loss of power post/ re-routed wastegate. It should also explain the turbo lag. The lag seems to be ok sometimes and horrible other times.

My friend hooked up the datalog and it shows timing of ~9 in the upper RPM regions during full boost. Seems a bit retarded timing which may also be a culprit.

 

It is either harware failure or very poor tuning.
Who did the install and tune?

At what rpm does it build the target boost?

 

I built it, and my older tuner (dont want to throw names out) tuned it. The dyno wasnt working so we couldnt tune based of HP & TQ figures. The timing does seem a bit conservative in upper RPM ranges.

I dont know if the turbo is damaged or not. It shouldnt be, and I trust Elltiot @ turblown as he said this turbo should be relatively quick spooling.

 

Boost leak, engine, or tuning. The lag between shifts is possibly due to your cast manifold but could be related to previous mentioned things.

thewird

 

Pictures of the exhaust system and intercooler system?

What catalytic converter are you using?

 

Do this first!

 

I'd bet it's a boost leak.

 

Again..... I have a 3inch full exhaust with a 3.5inch dp. No cat. Straight trough.
I barrowed a mini vac, not i just need to figure a way to pressure test my system.

Here is a horrible pic i have of ly setup. Ill get better pics

 

Timing seems pretty low considering you have a stock ported engine. Between that and a rich tune I can see the lower numbers. Do a boost leak test just to make sure it's all good there. But seems tune related.

 

There's no mysterious rags stuffed in the intercooler by chance?

 

lol I saw a thread a few weeks about how someone had a rag stuck in their I/C or something. I am certain that there is no such scenario here. But for the heck of it I will double check.

 

Thant is low even for pump gas. if we could see Your whole timing curve would be helpfull as it should be higher at lower rpm/boost and then taper down then in higher bost. this will affect spool and also affect top end power. . what ignition system is on the car?

 

my first thought is boost leak.

 

Post your timing maps! For 13lbs I would go with 12 split and still feel comfortable. Also I would lean it as far as 11.5-11.7. I doubt anything's wrong if you're seeing boost on your interior gauge; It's most likely tuning. That's why it always pays to find an experienced tuner...

 

As far as a boots leak you should be able to hear it or see signs of it around the couplers. Pull the couplers off and look for cuts, especially the one off the turbo.

Timming seems way retarded, can you post the data from the data logger. At least post whats going on across the 15psi pressure row. I think this is the issue personally

A/f @ 11. aren't that bad, could go leaner, but if/when you advance the timming it will lean out as you are starting the spark earlier and buring more fuel, creating more heat and more power.

Be sure you have no maniflod leaks and the bolts on the mainfold are tight. Check all bolts that hold the compressor and ehauxt housings to the CHRA for tightness. Is the exhaust wheel intact, You could pull it apart and see if the wheels have contacted the housing.

 

^^? have you ever boost leak tested?

It takes a custom PVC pipe end with a air compressor valve tapped into the end.

Clamp that sucker into the intake of a turbo with correct coupler.( use t boltsclamps if testing over 25+ psi.) GO grab you a spray bottle of water with a bit a dish washing soap in it. Spray everything! boost/vacuum hoses. all clamps. (Intercooler joints)Throttle body, EVRYTHING. Now have someone watch your boost gauge as you apply pressure about 5 psi over your target PSI. Watch for bubbles.

 

You can also just listen for the leaks, they are pretty loud at high pressure LOL.

thewird

 

Yep on Diesels running 60+ psi and my car which I found a leak around the lim and uim.

When I say look for signs, some times you can see where the leak is occuring. If the leak is large enough to effect spool you can hear it, the turbo spinning faster, trying to compensate, and the air gushing out the leak. I don't think this is his problem, could be wrong. Any more questions??

 

Joe,


Everyone's posts are right on track, just keep looking and double check everything. Just so we are clear, you have done an actual compression check right? You've got a 1.0 ar btw.