been having a few issues with the car lately which is an on/off thing but i still feel like it's not up to par with what it should be. I'm running 148mph with around 28-30psi fluctuating in 3rd/4th gear. 114mph at the 1/8. on the dyno we made right at 800 on 28-29psi dynapak. Does that seem like a low mph for you guys at that power level? I know low 900hp on a dynapak will/can go low 160mph traps.

Also my main issue is the car not boosting up. has anyone ever had a problem with the turbo binding up under a heavy shock/load at the track causing no boost? maybe the wheel hitting or slowing down from the binding. it does it every now and then and i've posted this problem before and talked to a few guys about it but it's really causing me to get horrible times from not having anything until right before the 330' mark.I'm also thinking it may be binding a little in the middle of a "good run" causing the turbo not to spool back up as fast. the way my turbo is placed may be the problem as this is the only setup like this I know of and it may be binding under engine torque even with solid mounts. I'm not opposed to setting it back up like a normal sidewinder setup again if this is the problem i just hate to change it and that not be it. I've went through everything else and it has to be mechancal i've also changed the gates out and it does the same thing. turbo is the only thing i'm down to. Also on the dyno the car is spot on no boost issues at all.

here's a pic of how the setup is. it's a dual backdoor ic setup with a vband off the turbo down to a vanjen clamp on the hotside ic

 

cant help ya man, but wow what a nice setup

 

could your ic clamp be leaking when the engine tq's, i've heard those clamps require a stiff engine mount. i would imagine if the wheel in the turbo were making contact with the housing that it will leave some marks. just a thought, love your car by the way its beautiful.

 

Ive seen this on high HP mustangs that have vbands on the turbo to throttle body, or intercooler. since there is no movement aloud the compressor housing will flex and cause the blade to touch the housing like your describing. i would put a hump hose right off the turbo and see if that fixes it.

 

i've done boost leak test after boost leak test and nothing. also when it is losing boost or not boosting at all it's not leaking to the atmosphere anywhere. don't hear the usual loss of air it just stops boosting then maybe halfaway down the track it will go back up in boost and drop completely off again. You can even hear the difference in the sound of the turbo. I always know when it's going to do it because you can't really hear the turbo spool(whistle). sometimes it even does it when i am in the burnout.it's not like it's losing a couple psi it's losing all but a couple. from 30psi down to nothing in no time.

 

when I talked to jason Hunt a couple weeks ago he explained the same thing that happened on one of their cars a while ago. i tried putting a regular coupler on the intercooler to piping but it's just a small 4'' long with no hump. I'm sure that still not letting it move enough. I just don't understand how some guys with front mounted turbos and vbands/vanjen setups aren't having any of this problems at all. from what i can also see is that the blade is still in great shape even on the edges where it could possibly hit the housing.

Here's a video from last night. This was the last past which was actually the best of the night. burnout was great built boost off 2step good could hear it spooling but as soon as i left it just stopped as you can see. the other passes the car would boost up like it did here but then totally quit spooling again down the track.
http://www.youtube.com/watch?v=RUYDSgv773A

 

lol well this looks like my type of lauch what ems is this on

 

Video tape it man. Mount your camera right in front of the compressor and make some passes. Keep at it bro, you will get it.

Also, you could put a small amount of dye on the compressor housing and see if that blade is really touching it.

 

My turbo is v-band right to the intercooler (Top mount to backdoor). At Summer Slam I ripped off the driver side mount causing the engine to sag a 1/4" or more. I never noticed it until after the race. The car never acted any different and I would think if THAT didnt cause an issue then your set up should be fine.

I'd switch the turbos out.


What kind of blow off vavles?

 

Are you running hondata Kpro? Are you running a Hondata or MAC boost solenoid. If so, did you install the diode across the solenoid wires.

http://www.hondata.com/forum/viewtopic.php?f=19&t=11031 (yea i know, this thread is for S300 not Kpro)

 

I think the design of your set up is what is causing your issue. maybe you're getting some weird turbulence within that section between turbo and manifold. My friend had simliar boost issues with a top mount. It would be really lazy building boost on launch and when the car would leave it would sometimes drop to zero. he switched to a AFI top mount and now it holds boost on the launch,through all gears and spools up faster between shifts

 

You can see the hondata/MAC valve in the pic. To the right of the fpr. I have yet to see an issue without the diode. I don't use em.


What are you using the two valves on the firewall for?

 

car is on kpro. Rick, it's running a tial Q bov. I would switch out turbos just to see if that makes a difference off the bat but nobody around here has the same turbo i could use and i'm not buying a new one without knowing for sure that's it. i don't think it's the wiring on the boost solenoid been running it this way before this setup. the boost when it works holds perfect what i set it to plus if it was a boost control problem it would still build the wg spring psi 15psi

 

that was when it was on the ams 1000

 

with the power you say your making the traps should be around the mid to low 160's. Did you check the center section for shaft play also i would send the turbo off to the manufacturer to be tested cause there's definitely something wrong. i'm also wondering about the placement of your wastegates. i would of set them up in a upside down V configuration with the pipe going in between the to waste gates.

 

Turbo specs?

 

I know for sure at the power it's at it won't touch 160's at all. It's not making the power to touch that maybe mid 150's. center section moves a little bit. wastegate location was a little dificult when we did this setup and i know they are not exactly where they should be placed but that seems to have no issue on that part of it yet. It's not overboosting or creeping.

turbo is a pte t4 billet 6768 .96ar backhousing

 

Paul if you want you can come down and jump on my dynojet. My Car at IFO trapped 150mph with 644whp.

Are you sure you dont have a hairline crack in your turbo manifold? It would still make boost but loose all kind of power.

 

What does your car weigh? A crack in the manifold is not his issue. If you watch the video, it is definitely something either mechanically hitting to stop the spool or electronically stopping it.

Paul, put some dye on the compressor inlet and video tape it. I bet you will find that your turbo is the culpret. I also would try the diode trick on your boost controller. I know it worked before, but that is an easy check.

 

im really interested in this thread to get some information as well

my car has damm near the same issue

i was fallng from 7200-3300 at launchkilling boost we went from a soft cut to a medium cut and it helped me out a little bit but still didnt solve the problem.

we started to question the aem as an issue before i threw a rod lol

 

2300lbs

 

see my car has been going 146-148 with what i guess would be about 100 more hp at the psi it's running. i know something is up i expected the car to go around mid 150's. what mph were you running in the 1/8. i don't have much boost at it down low but it's going 114ish in the 1/8. I'm thinking it's because the turbo isn't spooling/recovering as fast which all has to do with this issue i'm having.

my car weighs a little over 2300 w/driver. i've looked over the manifold thinking the same thing about a crack or leak and i've found nothing. it's ceramic coated now too so it would be easy to see where the crack/leak was coming from. I just don't see it being that either because of the issue of it sometimes running fine sometimes not.

 

in that video it just did it off the line and you couldn't hear the turbo even spooling/whistling up until it came alive. i'll take the comp housing off tonight and see if i can see any rubbing spots in anything. on the boost controller part i've ruled it out because even with the boost control settings completely off in kpro and the boost controller actually unhooked it still would do it and not build the wg psi. it also did the same thing when i was running the ams 1000.

 

Check your turbo if it spins freely by hand. Last week i went to the dyno and I'm losing 10 pounds of boost on spool up, I fix my wastegate leak but still something didn't felt right. It felt lagging the same way you are explaining, sometimes felt good then suddenly lagging. I went and checked my turbo and it spins freely and then it would get stock. Check it when the car is cold and when it gets hot after a run. Mine does it after a hard run.

 

Why two wastegates?Is that pipe divided?