S16g spool up

[airmail96]

I already did a search and i didn't really find what I was looking for. Right now i have a s16g no porting, a full N1 exhaust except the O2 housing, switched back to the stock intake cause i had a custom made 3in that wouldn't fit. And i also used the 2g install kit from slowboy. It seems like the turbo isn't spooling as quick as i thought it would though, I know your suppose to do 3rd gear pulls, but i tend to use second a lot . Anyway it seems like it will hang around 5psi till about 3800 rpm maybe a little more before it build up to 14psi is this normal? We did a boost leak test and everything was fine so any thoughts?

 

[phatTSi]

When I was running my small 16g, I would get full boost at about 3200. My o2 housing, manifold, and exhaust housing were all also ported.

 

[marcmsj]

i had a s16g with no porting and it definately spooled faster then that.

make sure your wastegate actuator isn't faulty... be sure the arm is on the flapper and that it's keeping it 100% closed.

 

[CanadianTSi]

You should see full boost around 3000-3200.

Check for Exhaust leaks pre-turbo.

 

[ChvyKc]

You should see full boost around 3000-3200.

Check for Exhaust leaks pre-turbo.

That is exactly what my buddy is hitting with his 2G with a 16G on it and he is at 19 pounds, even before he did all the head porting. I agree with CanadianTSi that you probably have an exhaust leak or some other problem, you should be at 14 pounds way before 3800.

 

[oldman]

Exhaust leak or boost leak or both.

 

[airmail96]

tightened down the exhaust manifold gasket a little, did a boost leak test came up negative went out for a drive. Car did the samething, no boost what so ever maybe 3psi till about 3500 then you see 5lbs then at 4000 it just shoots up, the rest of the 9psi. I'm starting to think its something with the turbo cause my car came back negative on leaks, but i dunno :-/

 

[1fast97gsx]

how are you guys performing boost leak tests? There's definitly a leak. How high are you pressurizing it?

 

[Zexell]

Is there any way to actually tell if theres a pre-exhaust boost leak???

 

[LessIsMore]

Theres only three places where a pre-turbo exhaust leak could occur. The first is between the head and manifold, the second is between turbo and manifold, and the last is cracks in the manifold.

Just for comparison my s16g begins building boost before 2000rpm, 9psi by 2500rpm and 15psi at 2900rpm. This is with a heavily ported turbine housing.

With your setup I would think you'd be having problems with boost creep if anything.

Try wiring your wastegate flapper shut and see if that helps. Just make sure to let off before 30psi if it does work since you'll have no boost control.

 

[ddavisaf]

Try wiring your wastegate flapper shut and see if that helps. Just make sure to let off before 30psi if it does work since you'll have no boost control.

I agree with everything else except for the 30 psi. Don't try and run 30 psi. 20... let off before 20....
You can't just decide to push 30 psi, you have to have your fuel maps set for 30.... Otherwise, you're going to lean WAY out and do some serious damage.

 

[airmail96]

what would wireing the waste gate shut do ? And i tihnk tuesday we are whipping out the big ole air compressor and taking soapy water water to everything, is that the best way to test for pre turbo leaks?

 

[airmail96]

after performign a soapy water test, we found a small hairline crack in the exhaust manifold that had gone all the way through, patching with jbweld for now but replacing soon.

 

[ddavisaf]

after performign a soapy water test, we found a small hairline crack in the exhaust manifold that had gone all the way through, patching with jbweld for now but replacing soon.

JBWeld will burn right away and will smell horrible. But you're replacing soon so it's more of a heads up than anything else. If you smell something, it's just the jbweld burning away.

 

[GEN1GST]

i am curious to see what your solution was for youre spool time. i put my s16g on today and have the similar problem. i know i have no exhaust leaks or boost leaks. i check every week. possibly be the wastegate, i had the s16g on my 14b and it seemed to work fine but now it just lagging , possibly boostcontroller???? im still tuning in my avc-r.
please let me know.

 

[DSMvroom]

what would wireing the waste gate shut do ? And i tihnk tuesday we are whipping out the big ole air compressor and taking soapy water water to everything, is that the best way to test for pre turbo leaks?

it ensures that all exhaust gasses pass through the impeller, but as stated above, it will eliminate all boost control so when you see it rise up like holy hell then you know it was your wastegate all along and it is time to LET OFF THE GAS!

Oh and FYI a "fun" way to check for some exhaust leaks is to use some seafoam! Kill two birds with one stone

 

[versatileperf]

check the nipple on teh wastegate,sounds wierd but mine was bent where the vacum hose goes,and i didnt spool a 14b up until like 3800 -4200 or something retard,and then a new wastegate and all took care of it

 

[GEN1GST]

it was the 16g wastegate!! it was bad, the sucker spools like a champ!!!!

 

[airmail96]

been kinda busy lately, found out my gasket is leaking air, took the car to the shoot out got beat by a stock awd 1g on the way home , haven't had a chance to change it yet though.

 

[GEN1GST]

dude you got served!! sucks!!!! NOT MAKING FUN OF. i had the same problem if you read it. it would start to make boost at like 4000 rpm. but i changed out my wastegate from the 16g to the 14b and its crazy! have you checked youre wastegate yet??? once you get that thing spoolin right youll love it!!

 

[airmail96]

yea the other day i dynoed it no boost controller hooked up and it hit peak power at 5500 rpm and held 15 pounds sold, with my 02 back exhaust. so i think the waste gate might be messed up