Reducing Boost Without Adjusting Actuator

[Carl.]

For some reason when i set my actuator to boost 0.8 bar or below it takes the turbo until above 4000 revs to spool up. but when i have it above 0.8 it spools up at 2000 - 2500 like it should. trouble is i then obviously hit fuel cut when i boot it.

does anyone know how to lower the boost to 0.8 bar but keep my actuator set above 0.8

i was hoping i could get a manual boost controller but i imagine they only restrict the vacuum pipes to increase boost.

any ideas??

[DavidAshton]

I know someone who had the exact same issue as you have described above.

What he did to cure it was put in the little metal reducer ring that comes with the hks actuators and that sorted it. No idea how / why but it did.

Strange actually, was also a white 98 spec he had.

If that dont work you could lower the actuator boost and try bringing it back upto 0.8 bar with a boost controller, ive got a manual one you could borrow if need be.

[Carl.]

what i think the problem is david is that when its set to 0.8 the arm is extended so much its really slack on the wastegate lever so exhaust gases are been allowed through. so i dont reckon a manual boost controller will do anything. thanks though bud

by the metal reducer ring do you mean the little copper/brass thing. ive got that in.. was actually thinking about taking it out to see if it does anything.

need to get my hands on an ecu so i can have best of both worlds lol

[durmz]

from what i can gather from what uve said is ure problem is boost creep. because, at 0.8 bar ure actuator is set slack and is already letting out gas from the get go, causing u loads of lag, but as soon as u tighten it the creep is then fucking u over.

at 0.8 bar the actuator should not be slack, u should have to pull on the actuator to get it attached to the wastegate arm

[Carl.]

at 0.8 bar the actuator should not be slack, u should have to pull on the actuator to get it attached to the wastegate arm

yeah, at 0.8 it just slips into place but if i increase it one turn i have to pull the arm.

ive ported wastegate to 25mm though.

i think im going to remove that reducer in the pipe and hopefully that will open the wastegate quicker when its needed to stop it over boosting

[DavidAshton]

What air filter set up are you using?

[Carl.]

its had standard airbox took off and a aftermarket airfilter slapped on end of the efi pipe. dont want to restrict it tho

[nastyrash 2003]

a quick way of increaing or reducing boost levels are by adding helper springs to your wastegate actuator. can be put on the standard actuator to increase boost, a very cheap way of increasing proformance.

[DavidAshton]

TMIC still?

[Carl.]

TMIC still?

yep.

i was driving round for ages with it set at 0.8 spooling at 4k ish thinking it wasnt slowing the car down too much bt then at cortonwood had a little blitz with a silver v n it left me straight from roundabout so i thought ohh must have been that lad with td04 set up. but then when he let me get at side of him and we both put footdown he couldnt get past me so im thinking wtf? so other day i decided to increase boost to see what it felt like and SHHHHHHHHHHHH*****TTT so much more power down low, couldnt believe what ive been missing since i started f**king about with it from standard.

[Carl.]

oo yeah forgot to say aswell, the same day i put boost up, clutch decided to slip. really really stunk and now bites right at top so gnna have to get a new one i think. hasnt slipped since though so i might just adjust it or time being

[nastyrash 2003]

TMIC still?

yep, do not cut corners at any point, mityvac tool comes in handy wen adusting turbo actuator, so you not leaving increased boost to chance, plus a boost gauge, exhaust temp sensor, oil presure gauge and temp, and wide band lamba if you can aford it. plus a throught on intake air temp, as heat soak can be a big problem wen increasing boost.

[durmz]

yeah, at 0.8 it just slips into place but if i increase it one turn i have to pull the arm.

ive ported wastegate to 25mm though.

i think im going to remove that reducer in the pipe and hopefully that will open the wastegate quicker when its needed to stop it over boosting

ure defo getting boost creep imo, thats ure problem, im sure of it because its the exact same as my car, atm i get around it by modulating my foot lol

[Carl.]

yep, do not cut corners at any point, mityvac tool comes in handy wen adusting turbo actuator, so you not leaving increased boost to chance, plus a boost gauge, exhaust temp sensor, oil presure gauge and temp, and wide band lamba if you can aford it. plus a throught on intake air temp, as heat soak can be a big problem wen increasing boost.

how does heat soak on tmic effect boost?

[Carl.]

something to do with the pressure increase from the air not been cooled enough?

[nastyrash 2003]

something to do with the pressure increase from the air not been cooled enough?

thermel efficenty. is wat its all about, as turbos boost increases, so does cylinder temp, thr are lots of reasons y, from the turbo design to a heated throttle body, recert valve or dump valve, air fuel ratio. and equaly many way to combat this from thermostates, to fuel coolers, the method tuners use is to simply add more fuel to cool cylinders, but bore wash can be a result as well as petrol (which has a low cytane rating) contaminating your engine oil, i tend to use engine mechanics first in the engine build things like cylinder quench. removing throttle body coolant pipes, and many more. but the effects of high air intake temps can mess everything up.

[DavidAshton]

I asked if you had a tmic because when I had mine on a tmic it would creep really bad, soon as i switched to fmic it settled down a lot.

I still cant get mine perfect even with the wastegate ported as much as possible, its still 1 bar creep to 1.1 and thats with a decent boost controller, ct9's are difficult to get boosting properly with a free flowing set up.

[durmz]

I asked if you had a tmic because when I had mine on a tmic it would creep really bad, soon as i switched to fmic it settled down a lot.

I still cant get mine perfect even with the wastegate ported as much as possible, its still 1 bar creep to 1.1 and thats with a decent boost controller, ct9's are difficult to get boosting properly with a free flowing set up.

yeah ile agree with that, ive had ct9 ported, not majorly though as mine had a crack, hks actuator, avcr boost controller ( one of the ebst imo) rx7 top mount, and i get creep like a whore, got a bit of a change up coming soon tough which im hoping will help me, getting hdi front mount which will give a small pressure drop and a new ct9b with no cracks in wastegate, so gonna port it right out, and a screamer style decat which increases flow of the wastegate, hopefully after that lot ile finally have it under control lol