S13 SR20DET redtop lagging

[NL-S13]

Wondering if anyone could help me pin point the issue. When I'm not under boost for a period of time( driving in slow traffic and can't get much boost built) the car tends to lag and not build up Set boost level when I hammer on it after traffic etc. Set for 15psi and after driving in traffic or under low boost it will reach 5-9psi Max but if I shut the car down and let it sit for 5-10 minutes and then try and hammer on it the lagging has gone. any suggestions help as this gets fairly annoying. It is a 1991 Silva K

[jedi03]

Heat soaking maybe? I noticed my s13 blacktop did the same and as evening came around I was pulling better...if you have Guage showing that you think it's your boost controller? What do you have overall?

[NL-S13]

It was happening long before I ever had a boost gauge or controller on it. And it can get like it in the night time and it isn't overly hot weather where I live

[jedi03]

Do you have a front mount or side mount intercooler?

[NL-S13]

Fmic it was happening also with the factory side mount

[jedi03]

Are you on the stock boost controller or aftermarket?

[NL-S13]

The boost controller I have is the AEM truboost but this was happening long before I put that in. I was running nothing at all everything was set up factory and it was still lagging then

[Kingtal0n]

As the engine gets hotter, and the turbo is sitting and heat soaking, such as in traffic on a hot day with the A/C on, the boost should build faster.

If you are watching the boost gauge, and noticing that it does not build faster under these circumstances, then I would replace your wastegate...
Speaking of which, is your car running the OEM solenoid still for boost control? The ECU may be sensing the high temps and reducing boost pressure (not sure if that is possible but something to consider)


I actually noticed a looong time ago that the stock turbo on these engines is no good for sitting in traffic, high temperatures, and heat soaks easily. I find myself disconnecting, or at least loosening the wastegate on these factory turbocharger units to prevent me from seeing big boost numbers when just trying to drive normally through traffic.

[NL-S13]

I have the factory boost solenoid disconnected and am running the truboost set up. I was told by the dealer I bought it off that it had an upgraded turbo to the s14 T28 and I am also running 550cc injectors

[Kingtal0n]

So how are you compensating for those injectors

if its a SAFC or similar then that may explain your "problem", Do you have a wideband is my next question...
or a custom ECU

[NL-S13]

Car came from Japan like it. I haven't ever opened the ecu but was told it had a tune. I have the aem wide band but I haven't hooked it up yet