slappy96

OK. I DO like the sequential. It has a completely different feel than TTC, but....I have a long transition from 1 to 2 turbos and I need help on the cause.

What I think- I think that the wastegate is a little tired and is bleeding boost early. My transition is roughly 3200rpm to about 4700rpm. Not rough but very distinct as the #1 turbo runs out of beans and the sound of the engine becomes very NA'ish. At 4700rpm the number two is introduced, but only produces a lot of power for about 1000rpm and tails off like the #1 alone. I'm definately not a boost guru, but that sounds to me like a weak wastegate. Spring mod?

Wrong assumptions or direction? Fire away.

soarer13oy

iTrader: (13)

I think the spring mod is only for ttc. Check out stu hagens 97suora website. You can search it on google

slappy96

The wastegate is the wastegate for sequential or TTC. If it's letting boost out early, wouldn't that affect the situation either way. I couldn't find anything that mentions this as a TTC specific mod. Only that a lot of TTC guys have done it.
I've been wrong a lot lately though...so

soarer13oy

iTrader: (13)

Im sorry the wastegate mod can be used on your seqential set up. Just looked it up on SF. Try it and update us.

For you sequential setup, did you make sure you have all the vacuum lines in the correct spot? #2 should go at around 4k rpm youll hear difference in you exhaust note. Itl sound more beasty. I know you have the upgraded twins but they should work the same. For mines number 1 will boost 12 drop to 10 and jump to 15. By 4k rpm il have 15psi. Do you have a boost guage installed? Check stus website if you havent theres a crap load of info on how to diagnose your seq. setup. Although i still havent figured mines out lol. It also has the vac diagram.

soarer13oy

iTrader: (13)

My damn boost issue is making me consider getting a high stall 3000-3200 rpm and just going ttc.

slappy96

I appreciate the update. I'm going to get a spring tomorrow and try it.

I know the sequential is frustrating. I would say keep trying just based on how long it took me.

Switching out a torque converter makes my hands hurt just thinking about it. Are you a pull the whole engine kinda guy or fight bellhousing, bloody knuckle 8 ft/ 14 extensions kinda guy.

soarer13oy

iTrader: (13)

Im a fight bellhousing bloody knuckles type of guy. Ive actually taken of and put on the transmission about 4 times by myself. With the car on jack stands. Very frustrating and time consuming.

Yeah im like 99% done with sequential its just wot sometimes it struggles to boost. If i ease into boost everythings perfect. Im going to triple check my vacuum. What do you think my problem is? Sometimes from a dig or a roll on wot my car will not boost or boost 2psi. Sometimes it would take off. Im thinking a vacuum leak or bad vsv, but ive replaced all my hoses. I want to go to the 1/4mi track one more time before they close, but theres no point if i can boost off the line.

slappy96

There are really only two possibilities since you replaced your pressure tank. 1. A boost leak. I'm thinking zip ties everywhere cause it only happens at wot with a slam of pressure all at once. It's exposing a leak only under stress or...
2. A tired actuator that works leaks a little under quick stress. I forgot, did you say you had mbc's in the mix? If so, maybe temp taking those out and see if wot gives you fits without them.

soarer13oy

iTrader: (13)

Yeah i have 2 mbc. I will be taking them out and testing the car without them. It could be a leaking actuator, but i will zip tie everything today.

slappy96

Spring mod had no effect with one of the lighter springs I got in the box. I was stepping into the springs thinking maybe it was an incremental deal. It's either not my issue or I'm going to have to use the whopper carb spring.

eliteskill

iTrader: (8)

Oh yay a sequential thread... Here I GO...

Sequential transition is 3500-4000rpm. If it is coming on too late your valves are not working correctly and your pretty much slaming your 2nd turbo to start. Spring mod works for sequential and TTC. It helps hold down a tired wastegate to hold boost longer. However this will not help your transition it only helps boost leak. Your transition relys on 2 valves the IAVC (intake). EGBV (exhaust gas). You need to check the VSV and these 2 values to make sure they are working correctly. STU's guide helps alot. If its coming on too late it might be your VSV not switching over to let the air in to the valve, or you have tired valve that requires more pressure to open. Or its sticky.. and doesnt close correctly. - boost leak -

Works for both. SEQ and TTC.

Sequential is troublesome. I fought with mine many times. It is the HOW the car should run. DO NOT TAKE THE EZ WAY OUT AND RUN TTC IT LAGS LIKE ****!!!! If your car is having problem boosting you need to make sure everything else is working first! before you add your boost controllers!

Take out your 2 MBC. Im running 2 as well for a boost off the 1st turbo as well. Make sure the car is running good STOCK before you add controllers and uping the boost.

There is a post on supraforums under my name with me going threw 4months of headache with my system. It finally works now, but I went threw the whole engine finding the problem. My 2nd turbo actuator was toast in the end.

I can help with testing if you are local. I have a mity-vac, and pretty familar with the whole sequential system now.

VSV + valve checks can be done in a day. Vacuum leak and boost leak is a different dragon to kill.

soarer13oy

iTrader: (13)

Im from sacramento. My transition comes on time the only problem i have is sometimes when i go wot from a dig it will either not boost, boost 2psi, or boost 5psi. Once it has switched to 2nd gear, it will boost all the way up again. Also at times from a roll and i punch it same symptoms, no boost, 2psi, or 5psi. I can let go of throttle and step on it and itl boost fine, but this sucks when im at the track as i lose so much time letting off and punching it again. Ive done temp. ttc and can only boost about 11, but this cures my boost problem. I did also replace my pressure tank.

I know ditching seq. is giving up, but so many guys on SF ditch the seq. system and get a torque converter to take care of the lag. Im not an all out drag racer, but id like to get a decent time. 14.2 ttc stock stall is very shameful for a 2jzgte bpu. My car is more for cruising, but id like everything working like it should.