Not getting enough force when Full Throttled...

[Essential_DSM]

You know how it feels like when your in a brand new Turbo-Charged car...? Even though the vehicle is slow but the turbo is there and you can feel the power from the turbo kicking in and forces you back to your seat?! Well my 92 talon is Forceful but I feel like there's power missing somewhere and i cant quite figure out why that's happening. I've raced my cousins STI and I smoked it but when i ride in his car, It feels so powerful compared to mine. I think it can be because of my head because I've checked the plumbing and boost and everything seems to be intact. But I know that on my head where the exhaust manifold attaches, I have the first two bolts on the left side and the top-left one is leaking oil and the one on the bottom left is stripped from the head. Can that be the cause of why i feel like there's a leak somewhere when i full throttle?

MODS:
BUSCHER 20G
BUSCHER FULL Exhaust
BUSCHER FMIC Kit
HOLLEY 660 Injectors

 

[danny_l_2005]

Now, it could be that your powerband can be more linear so your power comes gradually, but it could be that you might have a pre-turbo exhaust leak which is causing your turbo hit full boost at a higher rpm.

 

[Rob10_99]

So you smoked your friends 300hp awd car, if you had 300awhp you should know where to look first.
Was the car in good running shape before it went south? plugs/wires/timing/fuel ect?

I can tell you from exp, about a week ago fuels (all 91 pump) had changed and 3 of my friends cars started to knock even on partial acceleration!

I'm in AZ and as far as I know we only see two grades of 91pump.
Post a log if ya can,

 

[Essential_DSM]

Okay I have just retrieved my DSMlink today, and is not yet installed. but the car has been like this for quite some time now, and everything on that car is fine. everything that was mentioned; plugs, wires, fuel, timing. My next step is to replace the head if that's the last thing i have to do to figure out the problem. And the turbo boosts fine like it should.

 

[bob123131]

Don;t get ahead of yourself with a head rebuild. Have you already done a boost leak test you must do much more than just check if everything is intact i had a blown bov diaphram once and it made my car feel completely different. Also a compression tested, leak down test, and check to make sure your throttle cable is tight? Also im confused there is oil leaking from you exhaust man to head bolts? If so i would figure out where this is coming from. Possibly a leaking valve cover gasket or maybe even the head gasket, but if im understanding you correctly there is no reason oil should be leaking from there. Maybe im misunderstanding you though. I would say you are far from needing to rebuild the head with the info provided. Also you said, the dsmlink is not yet installed how are you tuning your 660cc? What gauges etc have you been using to tune etc? If you just have an safc2 or something and no wideband, egt, airfuel etc, your tune could be so far off giving your car that low reaction feel a complete list of mods would help.

 

[Essential_DSM]

I know that tuning is a big factor in why my car also feels like that but, the person who i bought the car from had a stripped bolt or I'm assuming that, that bolt was stripped and he attempted to re-tap that and accidentally drilled through the head. See that oil leak didn't start coming out until like two weeks after i had purchased the car. I know that the BOV is still in operable condition because I've swapped it a couple of times. But haven't done a compression test yet and since you've mentioned it, I'll get a compression test this weekend when i have some time. I've had my car tuned just a bit. I'm not familiar with tuning and I have a buddy that helps me do that. Still learning and I am still new with my car.

Other MODs:
EGT Gauge
FPR
MAF-T

 

[SnowBird]

You are missing a tune, thats it. That hole in the head you are talking about is no big deal, as long as he didnt drill through a cam or spring (which would be impossible to do unless you are an idiot). You should be able to just tap it and put a bolt through it, a short bolt that wont protrude too far into the head and stay out of the way of the internals. With a 20G you could just be feeling like its slow because of all the lag, but I would think you would feel it at higher RPM's. Get that thing tuned, especially if you have DSMlink, night and day difference.

 

[90laserRSfwd]

The stud you are talking about, if I'm picturing it correctly, is the one that needs to have some thread sealer put on it. There is one exhaust manifold stud that actually partially protrudes into the oil return galley in the cylinder head. I've had this happen on more then one customer car. If it's the stud that is on top of the manifold and closest to the oil feed line for the turbo, then we are talking about the same one. As for the stud that is broken or stripped, take off the manifold and put a helicoil in it. Helicoils are available at most auto parts stores for a couple bucks, that will help with your spool up time and top end boost. If the turbo to manifold bolts are loose that could cause slower spool up as well. The thing to remember about modified turbo cars is that the less restrictive the intake and exhaust are, the less the turbo has to work, which in turn makes it feel (we call it the butt dyno) like the car isn't as fast. Sorry for the novel, let us know how you make out.

-Jayce

BTW, you need to update your profile, a 20g, 272's Link, and 1000cc injectors don't tell us enough....

 

[DJYoshaBYD]

The first thing you should look at in any boosted car that has sudden power loss like that, is boost leaks.. They, in my opinion, are the number one most common cause for t power loss, stuttering, and delayed boost.. have you done an actual boost leak test? if you havent, then you need to...

As for the tune.. If your car, the way it is untuned, can beat and mid-low 13 second car, then you are on your way to having one hell of a beast when you do tune.. Not to mention reliable..

 

[srumel]

#1 The STI feels faster because it is a 2.4L motor whereas our's is a 2.0L. This means more out of boost torque and a quicker spool. And I'm not positive, but I believe it also has higher compression.

#2 The only stud that will leak if not properly sealed is the bottom center stud. This one is threaded into an oil drain in the head.

#3 Like an above poster said, just concentrate on repairing those stripped and/or leaking holes with a proper sealant or helicoil respectively.

#4 You have a fast car! Obviously faster than an STI. Don't worry about it! If you are looking for more low-end torque and a quicker spool, do a little research on the Cyclone intake manifold. This is a controversial subject because some say that the plenum has less volume, or the secondaries create turbulence...blah, blah, blah. From personal experience, I can tell you that it is well worth the swap when properly actuated/tuned, especially considering the price.

And for the love of God, don't pull the head to fix a nonexistant problem. If you are concerned about the combustion chambers do a compression test. If you're still not satisfied, do a leakdown test.

 

[90laserRSfwd]

srumel is right, I mixed that up. Sorry about that, good save srumel, thanks...

 

[srumel]

 

[DJYoshaBYD]

no only that, but it boosts at ~13 psi, I think.. if you have lower boost than those do, then they will feel faster..

edit: there is no way you could be at lower boost, because you smoked an sti, and you wouldnt be doing that at 7psi.. good stuff.. my bad.. im dumb.. ..

 

[Essential_DSM]

I appologize for the lack of update on my profile but i have the 272 crower cams and 1000 cc's, but haven't been installed yet because of this issue. Anyway I boost of a greddy profec b spec II boost controller and every time I set the boost at 20psi, it stays at 20 psi. No boost leak. I'll take everything into consideration and attempt these diagnostics. Thanks and I'll keep you guys posted

 

[tunethis]

I appologize for the lack of update on my profile but i have the 272 crower cams and 1000 cc's, but haven't been installed yet because of this issue. Anyway I boost of a greddy profec b spec II boost controller and every time I set the boost at 20psi, it stays at 20 psi. No boost leak. I'll take everything into consideration and attempt these diagnostics. Thanks and I'll keep you guys posted

You may still want to boost leak test it anyways. You never know. I've had major boost leaks at the injector isolators and throttle body but, my boost always held at 15psi. I fixed most of my leaks and it still holds at 15psi but, it pulls so much harder now.

 

[Essential_DSM]

Alright guys. Thank you all for contributing, Results................ Speechless. Did a compression test, leak-down test, and tune. The results can't get any better than what I've gone through today. A buddy of mine helped me fix my car today and the biggest issue was that the person who had the car prior, probably had adjusted the throttle cable so that it wasn't at 100% when WOT. DSM LINK read that it was only at 68%. So then we adjusted the throttle cable, remedy the timing and did some additional tuning. It took about 4 hours and we were done. Oh yeah just a leak from the throttle body, not a big issue. But the car pulled so hard that a roll from second gear at about 20 miles an hour, had me and my buddy stuck in our seats and I was loosing traction. It's an AWD! Well my 272 Crower Cams are going in, in a couple of weeks and my AEM wideband for a better tune. Some time this weekend I'm hooking up an additional fuel pump so I'll be running off two walbro 255s. Again Thanks for all of your Contributions.

 

[srumel]

Wow, if you were smoking an STI at 68% throttle, it can't imagine what 100% must feel like . It's good to hear that you found what the problem was.

 

[eboy0]

Alright guys. Thank you all for contributing, Results................ Speechless. Did a compression test, leak-down test, and tune. The results can't get any better than what I've gone through today. A buddy of mine helped me fix my car today and the biggest issue was that the person who had the car prior, probably had adjusted the throttle cable so that it wasn't at 100% when WOT. DSM LINK read that it was only at 68%. So then we adjusted the throttle cable, remedy the timing and did some additional tuning. It took about 4 hours and we were done. Oh yeah just a leak from the throttle body, not a big issue. But the car pulled so hard that a roll from second gear at about 20 miles an hour, had me and my buddy stuck in our seats and I was loosing traction. It's an AWD! Well my 272 Crower Cams are going in, in a couple of weeks and my AEM wideband for a better tune. Some time this weekend I'm hooking up an additional fuel pump so I'll be running off two walbro 255s. Again Thanks for all of your Contributions.

Damn... that thing must have soooo much slack it would have been quiet noticeable without DSMLink.... anyways, good work.