Late spool on Evo 16g. Please help.

[99evo3gsx]

Ok. My headgasket blew a few weeks ago and i had the head resurfaced, and put in a cometic 3-layer hp metal headgasket and arp head studs. I have an evo 3 16g. When i take off in first, my turbo won't start spooling till around 3,500 rpm and gets to full boost at around 5,500 to 6,000 rpm. When i shift to second, my turbo spools completely by 4,000 rpm, if not sooner. I know the headgasket lowered the compression, which would increase spool time, but i dont see why it takes so long in first and not as long in 2nd through 5th. It almost seems like it's reving faster then the turbo spools, and by the time it spools, I've only got about 1,500 rpm left in 1st.

Also, when i hit full boost (16 psi), it feels like it's pulling half as much as it used to.

If anyone has any idea why this is happening, please let me know. I really need to figure this out soon.

Thanks.

 

[miteclgst]

Lag decreases between gears because the turbo is already spooled and all of the rotational speed that you have to make up in the begining of the next gear is however much it lost while you switch gears. In first the turbo is not comming off of a full spool so you must "start from scratch" once you get going and the turbo spins faster it becomes easier to pick up speed.
The reason your car might feel a bit slower is because, as you said, you lost compression when you switched gaskets. 16psi at 8.0:1 is much different then 16psi at 7.5:1. You are filling a bigger cylinder and this requires more velocity being that everything else is the same.

 

[99evo3gsx]

Thanks for replying so soon. Last time i posted, no one answered. I agree with you, and that is what i thought was happening too, I just needed a second opinion to make sure. If anyone has any ideas as far as what to do to decrease my spoolup in 1st, please let me know. I plan on adding an evo 3 o2 housing, and already have a 3" apexi N1 downpipe and exhaust w/o cat. I really need to bring the spoolup down, as it doesnt spool till 5,500 - 6,000 rpm. That's quite a jump from the usual 3,000 - 3,500 rpm. It's like racing w/o a first gear. :thumbdown
Anyway, thanks for the help miteclgst.

 

[oldman]

How do you launch? If you do a 5k launch and slip your clutch in, you probably won't even have time to see if you hit full boost at 3k or 5k.

 

[rjgeier]

Do a boost leak check, that is most likely the problem. Or your running really rich.

 

[miteclgst]

Some of the things that will lower spool up time are properly ported exhaust manifolds, 02 housings and bigger exhausts. Anything that you can think of that will lower the restriction through the turbo the better off you will be. The oem exhaust manifold can be port-matched to both the header-to-manifold gasket and the manifold-to-turbo gasket. Did you have the turbo ported when you bought it? I'm asking this because if the gasket saving ring (ring that goes between the manifold and turbo) is no longer used, the step in the exhaust manifold that sandwitches the ring can be ported out. Gasket match the stock 02 housing to the turbo-to-02 housing gasket. And if you go this route make sure to port the wastegate runner really well. Then gasket match your 02 housing outlet to your DP gasket. Your main concern when porting is to smooth out the transistions between the parts, any kind of steps the exhaust gasses can encounter will create turbulance. Porting is one of the cheapest things you can do, as long as you have some tools. Most people use air driven die grinders with carbide bits. I didn't have a compressor so I used a Roto Zip, a good carbide bit will save you a lot of time. check out vfaq.com for a couple articles on porting the exhaust manifold and 02 housing. I don't know the extent of your mods, but if you don't have an exhaust you can still port match everything besides the 02 housing to dp flange. Also rich conditions cause slow spool up so if you have a means of controlling this (AFC...) then lean it up a little bit.
Check and make sure that you don't have a leak between the exhaust manifold and turbo, this will slow up spool also

 

[99evo3gsx]

Thanks for the responses. I do have a ported evo 3 16g, along with a full 3" apexi N1 exhaust. I have a brand new jet cut ss 7cm turbo to manifold gasket, just installed it when i changed the headgasket. head was also cleaned. I have the evo 3 o2 housing, just not installed yet. I plan on getting it ported before installing it. I was also planning on getting an evo 3 exhaust manifold, probably the SBR one. The reason why i got the HP head gasket instead of the standard gasket in the first place was because i plan on eventually running a 50 trim, and want the car to stay as reliable as possible. I don't want to have to replace the head gasket for a long time.

Also, do you think cams would help? I was thinking about upgrading to hks 272's and getting valves, valvesprings and retainers. This should allow me to rev higher, and since the turbo spools later, reving higher should help a lot. Any other ideas? Thanks for your help guys. I appreciate it.

Also, oldman you have a good point. I usually launch at around 5,500 - 6,000 rpm, so dragging i would be through the gear in no time. But for street driving, when i start in first without launching, it's a pooch. It feels completely unresponsive until 2nd gear.

I do have an safc-2, just not installed. I plan on leaning it out as soon as i install the safc.

Thanks for all the help guys and the quick responses.

 

[beat90tsi]

My E316g doesn't fully spool (20psi) until about 3500-3700 in 3rd gear.
I ported it last week, I have a full 3" exhaust w/02 elim, 3" test pipe, and 8.5CR. This seems like a late spool to me. I guess I should do a compression check, it has been a while.

Is 3500 late for the E316g, or does it just feel late after driving my buddy's STi?

 

[Piranhaman33]

i dont know if this would help but my buddies 14b spooled up real slow.......we noticed where the wastegate actuator arm connects to the turbo that it was sticking out some.....this would cause the wastegate flapper to not quite close off the passage.....so we took a rubber mallot and pounded it in. it took some time but as soon as we got it almost flush we ran it and it spooled insta-quick....so hopefully this helps. oh and by the way its happend to my 16g too, same treatment and spool was quicker

 

[Thomas91169]

no 3500rpm spool up on a evo16g is perfectly normal. i have a ported e316g with tubular o2 housing, 3" catback, cat still in place and reach full spool at 3200. my freind has e316g with no cat, stock o2 housing, and supra side mount and spools at 3800-4k.

mine is alot different beast than his, mine gradually pulls when it reaches full boost, his like is nothing till it hits 20psi then throws you back in the seat. we came to the conclusion that my turbo having the potential to flow more(ported and tubular o2) but restriced by a cat is hindering the kick in the ass spool that his has with no cat.

 

[beat90tsi]

so the supra smic that i forgot to mention in my first post, as well as my full 2.5" LICP and UICP may be adding a little to my spool time?

 

[beat90tsi]

at what rpm does your ported e316g reach 20psi in 3rd gear?

 

[beat90tsi]

anybody want to chime in on this one?

 

[RacethisTSI]

When i had mine it would probably build full boost (27 lbs) by 3500 or so in third gear

 

[_QueirOZ_]

Lag decreases between gears because the turbo is already spooled and all of the rotational speed that you have to make up in the begining of the next gear is however much it lost while you switch gears. In first the turbo is not comming off of a full spool so you must "start from scratch" once you get going and the turbo spins faster it becomes easier to pick up speed.
The reason your car might feel a bit slower is because, as you said, you lost compression when you switched gaskets. 16psi at 8.0:1 is much different then 16psi at 7.5:1. You are filling a bigger cylinder and this requires more velocity being that everything else is the same.

Nonono, lag decreases between gears because you got more LOAD to the motor, givin more exhaust gases passing through the turbine wheel. Even pushing from 1500rpm second gear will spool faster than first gear.

 

[Dan90tsi]

I have been doing lots of research on this problem with people and myself have slow spoolup with the evo 3 16g and i have came across a tip that I just tried and worked like magic! Alot of the problems seem to be the wastegate rod not holding the flapper tight. A quick fix until you can get a new one is to take the bolts off where the wastegate bolts to the turbo and put 2 to 4 washers behind there then bolt it back on. The washers put nore tension on the rod holding it shut nice and tight. I added 3 washers and my car went from full boost at 3700 to 3200 which is awesome!! Give it a try.

 

[pboglio]

^^^Good advice. 16g wastegate actuators come from the factory anywhere from lightly loaded to completely loose. A little preload with washers is a quick/easy way to fix this issue.

 

[JusMX141]

All it takes is the box to get dropped one time in the wrong place while the turbo is being shipped to you or while you're installing it for the actuator head to get pushed in a little, and it completely ruins the actuator's preload on the flapper arm.

 

[jabrow87]

yeah mine was loose on my e3gt 16g and drove it for a few months till i figured it out.. it was like night and day for lag

 

[Dan90tsi]

Yeah it took alot of research until i came across this little trick but it totally solved the problem. Anyone who has checked everything on their car 3 and 4 times now and still are having spool issues HAVE to give this a try and let us know your result.

 

[DSMer541]

Definetly try some washers on the wastegate, when i put my 16g on i had the same problem, the wastegate was not holding the flapper closed during spool and it seemed like the turbo just sucked, so i put on another wasegate from my 14b with a couple washers in there and i now have "kick in the ass boost" ,no lag launching in 1st, almost no lag rolling in 2nd, and hits 20 psi around 4000rpm ,spiking to 24, rolling from 3rd at 3500rpm and hits hard.... BTW i have 8:1 pistons .02 over bore and 4-layer Mitsu MLS.