How to modify ddp?

[suprahero]

I recently installed bic ddp. Since then my car has been spiking to abot 18 psi and then backfiring. (stuttering) It's almost like fuel cut, but different. Don't really know how to explain it. Before the ddp, I was running aroung 9.00 with my best time a 8.78 in an 1/8. Now I can't floor it cause my car spools too much and sputters. I have a manual boost controller, but my car still spikes to 18 psi. Would a electronic boost controller stop this? My wastegate is suppose to be set at 14 lbs., but apparently not.
Can I have the divorced pipe welded and extended to go back into the exhaust? Would this make it run more like it did before I installed it? I was also thinking about adding a muffler to divorced pipe. Maybe that will help. I don't know, that's why I'm posting on here. I really need some help, cause I'm tired of not being able to push the petal to the metal when racing. I raced tonight earlier and I did run a 9.13 but that was my best time and that used to be a bad run for me. Hope someone can offer some help............lol

 

[MKIIINA]

are you throwing a CEL when it starts jerking? what are your mods so far?

as for adding a muffler some people have talked about adding a motorcycle muffler to quiet things down. others reroute into where it starts to flaten out.

 

[suprajjang]

hmm well i currently have the BIC DDP but i am taking it off this week to weld a pipe to make it go back into the exhaust. As far as rerouting i dont see why you would have a problem since even bic offers a rerouted dp.

 

[suprahero]

It doesn't jerk. It more like stutters and goes pow! Like a backfire kindof. I have a lexus afm, 550's, 255 fuelpump, manual boost controller, safcii, new intercooler, garrett to4e. The car was running great before the ddp. I blew a headgasket while racing. While I redid my bhg, I installed the new ddp. Since then it hasn't ran good. It runs real good if I ease into the throttle. I just cant give it too much gas or it will goost too much and stutter. I'm just thinking that the ddp is letting the turbo spool up TOO much. Maybe if it had a little backpressure it would be more like it was with the HKS downpipe. Just grasping at straws.
I did outrun a new 06 mustang gt last night and a 2000gt with a 100 shot of nos, but I was outrunning them easier before the ddp. Before the ddp, my best time was an 8.78, since then it's been a 9.13. Also, the car would pin you back before when the turbo kicked in, now it doesn't. It may be because it kicks in earlier now with the ddp, and I just don't feel it as bad. There isn't anyone around here to help me work on it. Everyone around here works on older cars, and the dealerships work on the newer cars. I just don't thik the Toyota dealership would be able to help me. Thanks.
Edit: I said I blew a hg while racing. Well actually it was cracked when I bought the car, but I didn't realize it. I thought that I had a hose leaking 'cause I had to put anti-freeze in every other day. After taking the head off, I could see where it had been leaking for the past few months.

 

[IHI-RHC7]

Unplug your manual boost controller, and see if it boosts correctly. I think the problem is more related to the reinstallation of the head than the ddp install.

 

[supramike7m]

could be the ddp, as the ddp would alow the car to spool a lot sooner, and put the power to the ground. what were your 60 ft. times like, before and after? you are probably making more power now and getting more spin, maybe try some different tires? tells us what the 60' times are like.
Mike

 

[Insidious Surmiser]

my idea would be to get a ebc... that is if your wastegate can be sat lower... say 10 lbs? or lower would be better... that way the wastegate would open really low, but allow boost creep to a certain extent... i'm pretty sure the muffler idea would work pretty well too, like if you used a medium to high restriction muffler off of a very small displacement car (honda, geo)... there are several ways you could go w/ this, but i doubt re-routing it would help that much... jus test shit out... if the ebc won't work, sell it... and mufflers are like 10$ from the junk yard... if the muffler's too restrictive, get one w/ bigger diameter piping

 

[MKIIINA]

my idea would be to get a ebc... that is if your wastegate can be sat lower... say 10 lbs? or lower would be better... that way the wastegate would open really low, but allow boost creep to a certain extent... i'm pretty sure the muffler idea would work pretty well too, like if you used a medium to high restriction muffler off of a very small displacement car (honda, geo)... there are several ways you could go w/ this, but i doubt re-routing it would help that much... jus test shit out... if the ebc won't work, sell it... and mufflers are like 10$ from the junk yard... if the muffler's too restrictive, get one w/ bigger diameter piping

this is a terrible idea. a smaller muffler? thats like saying "oh i have a gash in my leg, lets cut it off" and would completely defeat the purpose of the ddp as youd just be adding a restriction further downstream.

suprahero: you didnt answer my question about the CEL. it really sounds like FC to me from overboosting due to the more effecient design of the DP. pull the MBC off and see what happen, check codes (if any) and get back to us.

 

[Insidious Surmiser]

it's called red neck mechanics, lol, fix it however you can... at least for the time being

^^^ he doesn't have a ebc either

 

[suprahero]

Hey Mkiii. I just got here to check the posts. I will take the mbc off tomorrow and see how it runs. I don't really think it's fuel cut, or at least not fuel cut I was hitting before my lexus afm install. It was easy to tell what fuel cut was then. Now it's more like a stutter. It doesn't fall on it's face, it just stutters a little and pops for some reason. I could film it tomorrow, but I haven't been able to upload a video on here yet. I've tried, but to no avail.

As for the smaller muffler. I was thinking about adding one to my small pipe on my divorced down pipe. The one that comes out of the wastegate. Either that or have it run back into the exhaust. My car just seemed to run so much better before the ddp. I know it is boosting more now, but it's actually too much boost. I don't really want 18-20 psi. Well you know I want it, but I don't want to tear anything up. Thirteen pounds is plenty for me.

My 60' times seem to be about the same. My best time ever is 8.784 and the 60' is 2.204.......The best time I've ran with the new ddp is 9.089 with my 60' being 2.357. I know that is a little difference, but it's the wrong way. My older 60' is faster, but it could have been temperature or track prep or anything. Maybe the mbc removal will help. I'll know tomorrow.......lol

 

[Insidious Surmiser]

aight, now i'm confused :-/ i thought you said in the first post you didn't have a mbc, lol

 

[suprahero]

I recently installed bic ddp. Since then my car has been spiking to abot 18 psi and then backfiring. (stuttering) It's almost like fuel cut, but different. Don't really know how to explain it. Before the ddp, I was running aroung 9.00 with my best time a 8.78 in an 1/8. Now I can't floor it cause my car spools too much and sputters. I have a manual boost controller, but my car still spikes to 18 psi. Would a electronic boost controller stop this? My wastegate is suppose to be set at 14 lbs., but apparently not.
Can I have the divorced pipe welded and extended to go back into the exhaust? Would this make it run more like it did before I installed it? I was also thinking about adding a muffler to divorced pipe. Maybe that will help. I don't know, that's why I'm posting on here. I really need some help, cause I'm tired of not being able to push the petal to the metal when racing. I raced tonight earlier and I did run a 9.13 but that was my best time and that used to be a bad run for me. Hope someone can offer some help............lol

I did state in the first post that I have a manual bc. I'm going to unhook it tomorrow and see if that helps......lol

 

[Insidious Surmiser]

oooo, aight i figured it out, i was getting ebc confused w/ mbc for some reason :-/ i have dumb moments:nono:

 

[tonysupra]

what type of mbc do you have and does it have any features like ceramic ball or light spring?

i'd check the safcII if you havent tuned it again after the hg and ddp install. would that do anything?

 

[suprahero]

I haven't changed my safcii, I haven't needed to. I can't remember what kind of mbc I have. I know it is blue and is about the size of a cigarette lighter. I can check tomorrow to see what type it is. I don't know if it has a ceramic ball or not.

Edit: My mbc is a turbo xs. I looked it up on HPF and I'm almost positive that is what I have.

 

[Insidious Surmiser]

try turning down the mbc and see what happens...

 

[Boss302]

how do you not know what boost controller yo have? hehe. running rich wouldn't doathis would it casue it shouldn't matter what he's boost if he can't burn it dumping all that fuel in there could be bogging down the system right? or his boost controler is kaput.

 

[suprahero]

Glad to see another Alabamian on here. Your car looks way sexy. I'm not really a big fan of the bra.... .............loving your car though.

 

[souprat]

it's not the DDP. something else. like a boost controller problem, something you missed when doing the hg, or something with the safc. a ddp is a simple device, therfor if it were to cause any problems they would be simple ones, like overboosting would mean turn down the boost. sounds like you have something alittle more complex. good luck, stick with the DDP.

 

[IHI-RHC7]

yeah, the DDP works flawlessly for us...