When i went non-seq I ported the wastegate with a 1.125" drill bit on a mill and i went until the drill touched the bottom of the casting. Now it seems like it is hard for me to get boost quickly, i have added a spring to the waste gate to keep it closed longer and it helped but i still don't seem to build 10 psi until about 4000-4500rpm. The ecu is still controlling the wastegate via the factory solenoid and i have a 3/8" home depot style valve between the wastegate and the solenoid fully open.

The wastegate door does cover the hole completely once closed.

thanx for any info

 

just to comment on your thread... I'm really not sure if that's what would have caused it, are you sure you didn't press the bit too far?

 

EBC or MBC should solve your problem. Try it.

 

You're non-sequential now.....get used to it.

Once you reach 4000rpm are you getting the desired boost and is it holding steady?

 

You ported your wastegate at the same time you went non-sequential?

And you're sure the wastegate is closing?

Well then, welcome to non-sequential (or single turbo, which is similar). The whole point of sequential is to mitigate the boost response issue below 4500.

Drilling into the casting slightly shouldn't be a problem unless you drilled through into the turbine scroll.

 

You added a spring to the w/g door? Never heard of that being done. Can you elaborate?

Also, in your sig it says that you trapped 114 at 10.5 psi on stock twins. Am I reading that right, or are you referring to your tire pressure?

 

yea a boost controller should do you. i am assuming he put the spring to work against the wg actuator. since he has a stock ecu and the duty cycle is set a spring may reduce the wg opening

 

We're talking some custom fabrication then. The stock wg is a small flapper door that is vacuum actuated.....

 

Rich I noted the same thing, if thats 10.5psi on stock twins. Its the fasted MPH I've ever seen with just those mods. I didn't think that was possible, especially with an M2 stage 3 ECU, which isn't programed for those mods but CAN be ran with a MP at that boost level. If so thats pretty impressive.

I trapped that with the mods I have in my sig at 14psi, granted I am untuned running rich, and was heatsoaked from waiting in line to run..

 

toolwik: no I definately didn't press the bit into the turbine, I stopped when it just touched the casting, I was doing it very slow, a few thou at time.

soru81: I will be working toward a better mbc than i have now.

ISUposs: I know that i won't have the same low end as before, that doesn't bother me, I have seen people post that they have full boost by 3500-3700 rpm, which I definately don't, and that they get a boost spike of about 12-14psi then it tapers off to 10 psi. My setup has about 5psi at 32-3500, 7psi by 3700, 8-9psi by 4000 and 10psi by about 4500. Desired boost above 4500 is holding pretty steady, about 10-11psi.

GoodfellaFD3S: Yes I added a spring between the nipple that comes off of the compressor housing and the end of the wastegate rod. I actually made two different springs, one using a carb throttle return and the other from a drum brake spring, I had an extra wastegate actuator so i used a tool used to test radiator caps that has a pressure gauge and found some springs that held the wastegate closed longer. I first found info on this here: http://www.scuderiaciriani.com/rx7/non-sequential.html
About 2/3 down the page in the non-sequential boost control section of the page.

about the trap speed, you are reading that right it was 10.5 psi, in 2003 it was the last drag race night at PIR, it was very cold, they started running at 7 and kicked everyone out at 8:30 because there were not enough people that showed up. By the time i came back the return road i was the first person in line every run. I made at least 8 runs and none of them were below 112mph and 2 passes were 114mph passes. Like i said heat soak was not a problem and it was a very cold night. This was also on very shitty street tires, none of the 60' were better than 2.0.

In the 2004 season i went one time and this time i had slicks, I was pulling off 1.6 and 1.7 60' times, best et of 12.6 and best mph of 108. One of the 12.6 runs was actually at 103. I got my best trap speeds when i never shifted to 4th, and my best et's when i did shift.

GoodfellaFD3S: The spring is on the outside for clarification, not internal. It is a helper spring.

 

Are you ported?

 

stock reman mazda

no portwork

stock turbo's setup sequential at that time

 

thank you

 

How did you go 114 in 3rd gear and an M2 ECU?

edit: Wheels maybe?

 

Opening the HD valve all the way will keep your boost lower. You must close the valve in order to build boost. I suggest that you start with the valve open about 4 full turns from the fully closed position. Check your boost, and close about 1/2 turn at a time (checking boost each time), until you see a reaction. Then close the valve in small increments until you find the right spot.

 

thanks adam c

Isu: Went 114 on stock wheels, stock tire size in 4th gear in 2003

Went 103-108 on 26 x 11.5 slicks on stock wheels 3rd/4th, read it again.

 

This explains it. Porting will help spool you 500, even 1000 rpm quicker. Its the non-seq thats how it works. 4000 sounds about average. You may knock off 300 or 500 RPM if your lucky with a proper boost controller.

 

thanx fatman, good info that i've either overlooked or never really seen in the past.

 

Har har. I sense sarcasm.
No but seriously you cant really expect to much better spooling than what you got. The boost controller is probably the last thing you can do . Or maybe your turbo's are on their way out (hope not)

 

I was serious, I would think that if the turbo's were on their way out that i would have a boost problem above 4500