Turbo lag problem

N

neg vacuum

Driver
Ok I have a s13 sr that is stock for the most part with front mount, 3in turbo back exhaust (straight pipe), gt28rs. Tunned power fc, 800cc injectors, greddy intake manifold, stock turbo manifold, greddy rocker arm stoppers.
When I start moving my car the boost slowly gets up to 10psi and then when I hit about 4k it jumps to 20psi. If I am drifting and fall to anywhere close to 4k rpm it boggs and I have to clutch it to get the power back up. My ign timing is on and I think I am going to check my mechanical timing. But havent yet. Any Idea you have let me know. Oh and I have done a comp. test and I am at 150 accross the board.
 
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If IGN timing is good mechanical timing (base timing) is good also, they work together. unless your car was tuned with the mechanical timing (base timing) Set wrong say at 17 degrees instead of 15 degrees.
 
Not true but thanks for your input. If your intake cam jumps time but your crank and exhaust cam stay in time then it can cause your mech to be off but your ign to still be on. Anyways thats not the problem though because I have good compression and this would be off. I know my timing is set right. I have checked it with a timing light and I have power fc pro so I can watch and adjust everything. Please shoot me some Ideas because I am running out of them.
 
Yeah thats what I am talking about. Ok thanks I will try a new boost controller. I dont think I have a boost leak. I welded up my icp I am only running 4 cupplers and my bov is v band and have checked it for a leak.

Oh and its a man boost controller. Its been on the car for 6 years now.
 
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i would start at the bc. I have a manual that is crazy sometimes 5 lbs sometimes 20 lbs and anywhere inbetween. Put a greddy ebc in and everything is money.
 
yeah especially if its a bleed type w. a ball and spring. the spring can go bad or the ball can get stuck. i would bypass the bc first and see if things change
 
Ok so if I bypass the boost controller than it will only boost to 10psi. It does that fairly quick. I am going to get a new one tomorrow and will update tomorrow.
 
try to open boost it and c if it goes up to 20psi fast and if it does its your bc ps dont hold it open boost u might blow something just c if it goes to 20 and let off
 
neg vacuum said:
Ok so if I bypass the boost controller than it will only boost to 10psi. It does that fairly quick. I am going to get a new one tomorrow and will update tomorrow.
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sounds like it was the bc then.

id invest in an electric boost controller if you can so you can have faster spool and tight boost control.
 
Currently I made 350whp and 380 torque at 20psi with stock cams. I just installed bc 264 cams yesterday and have not made it to the dyno do to the boost lag problem. I unhooked the bc to day and left it open and same old thing boosted slow tell 4k and than shot to spike. I only did this once in 4th gear. So that rules out bc. I also smoked my ic set up. I went through the turbo with everything still hooked up. I found a small leak in blov which is a tial but I know that this is ok because as soon as you hit boost it should shut off. More info on how to check the waste gate valve getting stuck open would be a help. I could pull the turbo off but would rather not since I would need a few hours and daily my car.

yuhtinkyuhslick said:
Wow 800cc injectors on an SR with a gt28rs. 550cc or 650cc is more than enough. How much power are you making?
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I agree but the price dif is so small when you are buying big inj. See this way if I decide to go E85 I can.
 
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a 28 with greddy intake mani and large fmic u should spool about 4k. But what i dont understand is why it is intermidant like one time 4k 10psi and 1 time 20psi at 4k thats what i dont understand
 
It always spools up to 20psi but takes to long and the big problem is if I am drifting and I fall under 4k I loose so much power and it bogs. The thing is that it hasent always done this. It started about 4 months ago and will randomly spool quick. I know people running gt2871r (bigger than mine) same intake and 272 cams that spool alot faster than I am right now.
 
Im confused I thought you were saying when you bypassed the bc it was ok.

Then what gsracer said is more than likely true, its your actuator.
 
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