RTEC Engineering - 3000GT staged upgrades

3000GT staged upgrades

This page describes a possible upgrade path for the 3000GT / Stealth (TwinTurbo)

Please note : Every engine is in a different condition. Even at a low boost of 0.8 bars I found knock on a 3S car. Others haven't shown any sign of detonation even at 1.1 bars with the same modifications. Therefore, it is NOT possible to tell how much boost is possible on any stage and the given numbers are the limits for an engine that is in good condition.

RTEC Stage	Parts	Description	Recommendations

Stage 1 (max 14.7psi)	Air filter modification - drop-in element or - open element filter	For Stage 1, the filter is the easiest modification although it is possible that no gain will be seen. This because replacing a dirty filter with a new one always results in better breathing capabilities. But it is the base in the tuning path as the more boost is increased the more any restriction in the breathing path counts.	- K&N Aircharger - K&N FIPK - K&N Drop-In filter
	Boost Controller - bleeder valve - manual boost controller - electronic boost controller	On the 3S cars boost can "easily" be increased by installing a device that alters the pressure in a specific vacuum hose. Installation of such a device depends on the controller used. A bleeder valve mod and manual boost controllers work but are not able to give the full performance and lack of any security option. The later is very important to prevent damage !	- Blitz DSBC - APEXi S-AVC-R
options :	BOV - recirculating BPV - blow off valve	Often after installing an open filter element, a strange "owl"-sound can be heard under partial acceleration. This is NOT a faulty stock bypass valve but the stock design includes a small hole that is responsible for this sound as the valve opens a little. The sound is NOT a problem just anyoing. It is also an investment in future upgrades.	- Greddy Type S - DSM 1.st gen BPV
	Ignition wires	If the cars mileage is already high, replacing the stock wires is recommend. At this time some "high performance" wires can be installed but there will no gain !	- stock wires - Jacobs 8.5 mm - Magnecor 8.5 mm
important :	regapping plugs	When boost is increased, the spark will have to work "harder" to travel. Therefore the gap should be decreased to about 0.032". If the cars mileage is high or the plugs in a bad condition they should be replaced too.	- stock plugs
	boost gauge	The stock boost gauge does NOT show accurate boost as the amount is calculated upon the amount of air is measured. For a precise reading a real boost gauge should be installed. This is not recommended when an electronic boost controller is used (already integrated)	- Blitz - APEXi - HKS - Omori
	fuel system	The stock fuel system is equipped with 360cc injectors. At 14psi the injectors are on an IDC of 98% or even more. It is NOT recommended to drive any injector above 80% for a longer period. Therefore the boost MUST be limited to 14.7 psi whereas IDC already reached 100%.

Stage 2 (max 15psi boost)	Exhaust modification	The exhaust modification is an important part to allow the engine to breath. But it is important to read the comments as the combination is what rules !
	Gutting pre-cats	This is a very important part as the pre-cats are the first restrictions AFTER the turbos (the turbo itself is a restriction !!). This mod frees up the turbo and let it spool up quicker for better acceleration and earlier boost, as well as less lag.
	Downpipe	The stock dp design is bad (the rear enters in a 90° angle to the front stream!) and heavy. Any better design is recommend as this will prevent the stock restriction. There are downpipes that already eliminates the front pre-cat.	- Stillen - ATR - Buschur
	Cat-back exhaust	Only when all mods beforehand are done, an aftermarket exhaust can help to gain power. Even more it may help as the weight reduction together with the rest of the exhaust part is worth a few tenths !	- Stillen - ATR
options :	Main-cat	The stock main cat is big enough but will not fit any downpipe. Therefore a high flow cat or for track usage a test-pipe can be installed. Some downpipes already eliminate the cat.	- ATR high flow
note :	exhaust	It is important to know that an aftermarket exhaust only gives you sound and no power if the pre-cats and downpipe are still there. We do recommend to add the cat-back as the latest modification on street cars if weight is not really an issue !

Stage 3 (max 17psi boost)	Fuel System Injectors (440cc - 860cc)	To be able to run more boost, the desired amount of fuel must be delivered. Original DSM 440cc injectors are a possible way with the stock ECU but fuel cut could be initiated pretty soon as the fuel table is not in the right dimensions.	- Denso inj. - RC Eng. inj.
	Air/Fuel controller or ECU upgrade	A fuel controller is needed to tweak the ECU for the larger injectors. When installing a modified ECU, any fuel controller is not needed, but would help for fine tuning ! Fuel controllers like the ARC-GP2 do replace the stock Mass air sensor with a MAF sensor to remove the restriction in the intake path.	- APEXi S-AFC (old) (only up to 440cc) - APEXi S-AFC (new) (only up to 560cc) - Split Sec/GT-PRO ARC-GP2
	Fuel pump	When increasing boost the fuel pressure may drop in the top end. Therefore a larger in-tank pump is needed.	- HKS high flow - Denso high flow - Supra pump - Walbro High Press
options :	A/F meter	If an AFC is not equipped with an A/F gauge a good one must be installed to make sure not running too lean.	- SplitSec ARM-1
	EGT meter	It is important to know what is going on in the car. At this stage, and EGT makes sense to see where the cars limits are and to prevent damage. High EGTs (above 870 °C) are harmful to the internals. It is possible that EGT rises highly when the timing is decreased. But also a low timing also means present of knock and therefore another danger forthe engine !	- Blitz - APEXi - Autometer
	Water/Alcohol Injection	Even with dumping fuel into the chambers knock may appear even on low boost ! If the intake temperature is too high detonation may occur much earlier than thought. Water Injection can help to cool down the temperature and to increase the knock resistance like high octane fuel. Alcohol is only recommend if the installed fuel system cannot deliver enough fuel !	- ERL Aquamist
important :	Data logging	When boost is increased, detonation may occur due to the high intake temperature. Observing the knock sensor is only possible with a 1st gen car as no other tool is able to record the sensors signal. For a proper tuning datalogging is the most helpful tool and the only way to know if the car is safe !	- TMO DSM Datalogger
	Knock sensor	It is not yet possible to read the knock sensor with any external tool (without the Datalogger). Therefore an external knock sensor can be used. TRhe MSD product will be threaded into a hole in the block and acts like a microphone. There are not yet any experience available	- MSD knock sensor
note :	boost	Even with all the modifications, knock can still be found on low boost. Unfortunately knock this is only readable on 1st gen cars with the TMO Datalogger. Therefore, A/F ratio and EGT must be watched closely when boost is increased !

Stage 4 (max xx psi boost)	Turbo
options :
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Stage 5 (max xx psi boost)	Intercooler
options :
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Stage 6 (max xx psi boost)	Internals
options :
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