no bottom end power

[thecannoliman121]

so here is the deal. I re built my engine. put all of the necessary upgrades to it to make it compatible with the bigger turbo. I have checked and fixed all vacuum and boost leaks. but for some reason I have almost no bottom end power. I am having a hard time trying to figure this out. it is the last thing I need to fix and I can finally drive it. I really need this car for the snow because my other car sucks in the snow! can someone please help me figure out this final problem?

upgrades:
-fuel pressure regulator (37 pounds)
-16 g tdo5h turbo
-255 walbro fuel pump
-750 injectors
-dsm link chip
-boost gauge
-wide band 02 sensor
-2g mas

 

[LIV4PSI]

Maybe pre-turbo exhaust leak?

 

[jnava]

I was at first thinking you were doing a whole build with upgraded pistons and rods. I was assuming you were going to have a huge turbo. 16g's are quick spool up and you should definitely notice the power. Have you already dialed in your sensor on link? As the other poster indicated, make sure you don't have an pre-turbo leak. Make sure your bov is operating correctly and your boost controller is actually working. I personally had a boost controller that didn't work which felt like i had no turbo.

 

[mitsuturbo]

All the things previously stated here, but i'd start by checking base and mechanical timing. It may also be a good idea to do a leakdown and compression test, just to rule out any mechanical issues.

 

[fuel]

how much boost are you seeing below 3000-4000rpm in the higher gears?

 

[thecannoliman121]

i did put better quality pistons and rods and valves in it. but ive already done a boost leak test, and I do not have a bc. there are no leaks anywhere, maybe really small ones but nothing that would make a significant change. around 3000-4000 in the higher gears im making about 10 lbs of boost. then in a higher gear the bottom end is still sluggish.

 

[thecman02]

You have an issue of some sort. Seems like a pre-turbine exhaust leak. If you have an old manifold check for leaks. My old 16g would put out useable boost by 2500 in any gear.

 

[thecannoliman121]

alright. ill check it out. I do hear a leak up front I think. but so if isn't that or the timing is there anything else I should check out?

 

[vr4play]

Sounds to me like the mechanical timing is off. I have a similar setup and in cold weather it blows the tires off at 3k rpm in first and sometimes in second. I would check and make sure the cam timing is correct and that you have the base timing set. Also if you have set the base timing make sure the connector is not still grounded. I can say that I made that mistake on the dyno and the car makes no power with 5 deg of timing all the time.

 

[thecannoliman121]

alright. ive checked my timing. it is all set and now I am lost. I have no clue wtf to do. im thinking if it could be bad gas. but I don't think that it would solve my bottom end power! any other suggestions?

 

[r4pt0x]

Does the boost rise smoothly over a reasonable rpm range, or does it just kick in from ~0 to (over) maximum pressure?

If it rises spontaneously check your wastegate if it's stuck or always slightly opened. Also check your turbo for shaft play and free blades - wouldn't be the first turbo with a nut or bolt in it...

Check the control lines from/to the WG solenoid. Not sure if it's identical on the older ECUs (please someone verify this!), but with the later evo ECUs the valve should be open between pressure side and wastegate actuator on ignition off (or solenoid unplugged) - the ECU closes the valve (100% duty cycle) at ign. ON (or from ~1500rpm upwards) and decreases duty cycle to increase pressure on the wastegate actuator and open the wastegate.
Its a failsafe configuration - if your solenoid or electric wiring is faulty, you'll only get "wastegate pressure" as the actuator will be directly connected to pressure side.
If its connected the wrong way your ECU will pass through the pressure to the wastegate from lowest RPM until the WGDC decreases - boost will increase slowly and at higher rpms it will completely overboost...

Also pressurize your piping from right after the turbo outlet to find any boost leak. Disconnect the hose at BOV outlet and keep an eye on it (block it with your hand) while increasing the pressure. None of the >20 year old galant BOVs i've seen so far were able to keep more than ~0,7-0,8 bar. Most of them started to leak at 0.5bar (~7psi) or even lower. Even "new" ones didn't manage much over 1 bar without heavy leaking - i think most of them were produced back when the cars were sold and the membranes are brittle, so IMHO the best solution when going for higher boost is the evo 8/9 RS metal BOV.

 

[thecannoliman121]

alright. here is what I have done. I went ahead and took the turbo and manifold off to check it. the gasket for the manifold to turbo was completely trashed. so im guessing that was the big leak I was having. so that may be my problem. the gaskets are coming in today for it so once I go and get them then I will put them in and try that out. god I love working in the snow and in the dark haha. wish me luck /ubbthreads/images/graemlins/rofl.gif

 

[r4pt0x]

Was the inner ring missing/damaged? It protects the gasket from being burned and should always be replaced when removing the turbo.
Don't bother porting the turbo and/or manifold here - it will decrease gas speeds (which is bad) and is a master recipe for blown gaskets...
I had to use a ported evo3 turbo once - throttle response and boost buildup was worse than with the stock evo3 turbo with the gasket ring and I had to replace the gasket twice a year.