Boost when stopped

[mdelorimier]

Hi,

This might be a silly question, but i can't seem to google the answer.
Is it normal that when the car is stopped and i rev it, i do not get any boost past 1 PSI?

When the car is mooving, i get my boost corectly.

Thanks in advance

[bobbo]

That is very normal. In neutral you can't produce enough load on the engine.

[mdelorimier]

Ok, some mor silly question :

I got 2 gt2860 and full boost only comes at around 5 000 rpms, is there a safe way to get that down.
Also, on my pfc the duty has to be at 100% for it to go up to 1.3 bar.

I have blitz blow off valves (x2)
The actuators on the turbos stay closed and are relatively tight
No boost leak
I am able to produce 430 whp

[rvander1992]

Mods in order of ease:
Cat delete
bigger exhaust
bigger dump pipes
ported dump pipes, turbos, exhaust manifolds
better intercooler piping(i.e divided dump pipe, more efficient piping routes to intercooler, better flowing intercooler).
ported/polished head
higher lift cams with bigger valves(no point in bigger valves)
More retarded exhuast timing advanced intake timing(i think thats the right order?) - requires fine tuning


All this will generate smoother flow or more flow in the case of larger valves. You need more flow to spin the larger exhaust wheel up sooner which will in turn spin the intake compressor and get you boost sooner.

[mdelorimier]

Ok,

Cat delete is done
Exhaust is 3in. or so
SS Dump pipes are done
Stock cast proted manifolds are done
I am planing on doing the twin turbo pipe divider soon

Which cams would you suggest?

[rvander1992]

I'm far from the person to suggest you head work as I've never done it and I'm very new to the engine scene. Divided pipe should help a little but won't do that much. Beyond that I'm not sure what advice to offer.

[bobbo]

430whp is a good, safe number for those mods. Who tuned it? Almasi?

[Dragon Humper]

430whp on a heartbreaker dyno like a Mustang is pretty decent and 5000rpm is a bit high but not un expected. You can drop that a bit with cam timing adjustments and a really crisp off boost tune. My T88 was all in at 1.5bar at 5200rpm and made 600~ whp. A MAP based ECU helps too because you know in the tables exactly where the cross-over to boost is happening. An Ljetro (MAF) needs a whole bunch of fine tuning to achieve that and most tuners dont care to spend the time finding the transition point.



Jon.

[Skym]

Cam timing, cams, free flowing exhaust, adjustable wastegates, boost controller + ECU retune.

Why do turbo's spin up earlier with aftermarket cams?, because there's more air entering engine at lower rpms with aftermarket cams (also throughout powerband) and combined with more fuel from ECU tune = more exhaust gas to help spin the exhaust wheel on the turbo's.

From what I understand, cam timing helps to determine if there is more at bottomend with loss of topend or more topend at loss of bottomend. Or someehere inbetween. Basically adjust's the powerband.

[mdelorimier]

Wow guys, thanks for all the feedback,

I definetly have a "free flow exhaust" as i have de-cated my cat and it's pretty much straight from the front.
The down pipe is quite large, apexi if i recall and the dumps are also aftermarket ss.

I might do a bigger port on the headers an other time (might have been shy with the die grinder the first time).

It got tuned by Pat at ACSP who i think did a great job.

I will definetly consider cams.

Also, i think my clutch is on it's way out so i'm changing it. Can that help in any way?


Thanka again