killer lag on a gt28rs. need help

[ripped200sx]

im no expert, or even close, on turbos so im turning to u guys for sum help. first ill give u the specs so u know what im dealing with.s13 with a sr20det, dicktator management, rising rate fuel pressure reg, brand new wahlbro fuel pump, 63mm exhaust, fmi with 60mm tubeing and a gt28sr turbo.car runs fine, 180kw at 0.8 bar boost. thing is it only reaches full boost at 5000rpm.being a ball-bearing turbo it should b hitting full boost at around 3000 to 3500rpm. had the car at S.A.C for a re-map but they couldnt get the boost to come in any sooner. about to pull the turbo off to have it checked, but if any1 knows what i could try ull b saveing me a lot of time and trouble.shot-alot.[/img]

[The Calibrator]

Add nitrous?

Seriously now
What exh manifold are you running? Have you restricted the oil flow into the turbo?
How much timing adv are they running? 0.8 should be at around 4 to 4.5 based on the other cars I have done.
What wastegate and what boost controller?

If you are in Gauteng maybe you should bring the car past so i can look at it.

[Vlade]

Ummm what is .AR is the exhaust housing? .84 will come in a later (estimated guess 4500rpm at latest) think Duane can give you better figures...

Air cooling and route it follows, complicated routes can also cause lag...


Boost controller: To keep the waistgate completely closed till full boost is reached, this can also help with response?

[n1smo200sx]

Running the standard exhaust manifold could be half your problem. It's a HUGE restriction on the sr20 as soon as you put a big turbo.Maybe check the exhaust wheel size on that turbo.

[The Calibrator]

Sorry I have 2 cars with std exhaust manifold running a GT2871 and gt2876 respectively and they both hit 0.8 bar at just over 4000rpm. Both have 0.2 bar at 2000 near 0.5 at 3000rpm
The GT28 is by no means a big turbo

[ripped200sx]

standard manifold, .AR 60,replaced oil feed with a braided pipe. as for the timeing, dont have a clue. i moved the battery to the boot to free up space for the intercooler pipes, so i dont have any sharp bends. thanks 4 the offer but stay in the cape.

[The Calibrator]

Ball bearing turbos must have a restrictor in the oil line as they need minimal oil. I usually braze the banjo bolt outlet closed and then make a 1.5mm hole in it.

At sea level you should have 0.8 bar under 4000rpm.
Have you had the car mapped by someone who actually knows how to tune cars?

Judging by the amount of CApe Town cars in my workshop they must be in short supply down there.

[ripped200sx]

Steves auto clinic had a go.but no luck.there is one more person im gona try but have to wait till next month.fully booked.

[www.MotorCade.co.za]

Steves auto clinic had a go.but no luck.there is one more person im gona try but have to wait till next month.fully booked.

If you are taking it to SAC in Milnerton, I would never take it there, they like to blow up engines and parts, at your cost.

You could have a boost leak aswell, are you running a boost controller?

And adjusting the wastegate should actually solve it, to my knowledge.

[ripped200sx]

no boost controller and no external wastegate.what boost controller do u guys recomend and can it be fitted without remapping?

[www.MotorCade.co.za]

Seems nobody want to help you. Your internal wastegate can be adjusted.

As for boost controllers, there are a lot on the market, I just got new GReddy ones.

But it really depends on your pocket what you'd like to spend.

You looking at about 2-3k for a really decent one, but you can get a quite reliable manual one for R500, but don't expect much hey.