Ever since I installed my 20g turbo, I've noticed a lot of lag. Now I knew there was going to be more lag then my 16g, but not this much. I was wondering where everyone hit full boost (please state how much boost your running) as I don't see full boost (18 psi) until about 5k.

16g setup
2.5" dp from HRC
3" test pipe
3" apexi N1 cat back
stock trans

20g setup
3" Eliminator dp w/ vband clamp from HRC
3" high flo cat
3" apexi N1 cat back w/ just the muffler section swapped out for a 3g muffler which is 2.5" inlet and outlet.
stock trans for a little bit until I streched out 4th gear then installed the 3.55

So do you think if I gut the high flo cat and put my apexi muffler section back on it will spool up that much quicker? Or is this normal lag for this turbo?

from my understandings...this is pretty close to normal. unless you have a built motor...also...the less exhaust/backpressure you have the faster the turbo will spool. if I'm not mistaken...I'm sure someone with chime in and correct me if I'm wrong.good question BTW

I spool up way lower than that with the standard HRC 20g. I hit 15psi at around 3800 to 4000. Thats with the small HRC downpipe and 2.5 inch exhaust.

Might have some pre-turbo exhaust leaks, should be spooling up a lot sooner than that I would think. Did you use new gaskets when you installed the turbo?

Yep new gaskets and my vacuum sits right near 20 at idle. So what would you all recommend besides testing for leaks again?

Here is my mod list for anyone that might have questions:

Fully built 420A w/
8:8;1 JE Pistons w/ JE rings
Eagle H-Beam rods
Clevite main and rod bearings
Melling Oil Pump
New Water Pump
MLS Headgasket
ARP Head studs
PT Rockers/Lifters
Fidanza Cam Gears
Head w/ 3angle valve job
s20g turbo
Hahn FMIC
K&N Air Filter
Hallman Pro MBC
Greddy Type-S BOV
HRC 3" Eliminator DP w/ Vband clamp
3" Magna-Flo High Flow Cat
3" Apex'i N1 Cat-back
3g muffler (just replaces muffler section about 2.5" inlet/outlet...cops here are A holes)
NGK Plugs & Wires
Optima Red Top Battery
Clutch Masters Stage 4 Clutch (6 puck)
LC-1 WBO2 Sensor
-10an SS Oil Return Line
Megasquirt & Spark Engine Mng - Brd I/v.2.2 w/flyback - 4 bar map sensor - custom heat sink
Aeromotive 1:1 FPR
Bosch 780cc Injectors
Walbro 255lph HP fuel pump
-6an SS Fuel Line
3.55 neon trans

Hmm, boost leaks would be my next recommendation to check for. Have you got a chance to try one yet?

Do you have stock cams? I didnt see anything about them in your mod list. I have crower stage 2 turbo cams. I dont know if the cams make that much of a difference but my mods are about the same as you besides cams. Also is the turbo brand new? I know when i first got mine it took a little longer to spool up than it does now.

Yah I do not have cams...but they are next on the list though. Yes the turbo is pretty much brand new. I would say it has about...3k miles on it maybe. So how long was it before yours started spoolin up quicker? I would think 3k would be pretty much broken in, but I don't know.

I made a boost leak tester a while back...I'll check today after work. I think the last time I checked the only place was the TB, but as we all know thats normal. Some pack it with grease, but that only lasts a few months. I've been looking into maybe getting the MP 60mm TB, but don't know yet.

Either way, I'll check the leaks tonight.

It really took about 3000k miles of boosted miles( not breaking the engine in) before i noticed a difference. Honestly though i dont think it was a 1000 rpm difference between when it was new and now. Are you tuned pretty well or are you way off. Besides exhaust/boost leaks the only other thing i could think of would be your tune.

yah I am pretty out of tune right now and need to find some time to go tune it. My car has been acting pretty wacky lately especially with the heat. It was 116 here yesterday and my A/Fs were going nuts.

Originally posted by Aggression
yah I am pretty out of tune right now and need to find some time to go tune it. My car has been acting pretty wacky lately especially with the heat. It was 116 here yesterday and my A/Fs were going nuts.

Move to hawaii its 84 in the summer and 80 in the winter :)

yes im bragging

OK, well I checked again for boost leaks and none were found. The only leak is coming from the TB...that little leak nobody can fix unless you pack some grease in there, even then its not a full blown solution.

I've heard some say the MP 60mm TB doesn't leak. Might have to get one if thats the only sure fire way of getting rid of it for good.

But I hardly doubt that would cause this issue, as I had the same leak with my s16g setup and it had no effect on it.

So WTF is going on?....LOL

I gutted my highflo cat just now, but realize I can't really get on it now cause I just installed a new clutch.

Anyone have any ideas?

I see you have adjustable gears. Just make sure they didn't slip on you and everything is still in time. Just a thought, idk?

I'll double check that...thanks!