Upgrading 147 1.9 JTDm 16V
first-off let me say that i am very impressed by this forum. The amount of JTD knowledge and interesting projects is so much higher than in the german alfa-forums.
My name is Moritz, i am from Germany and drive an Alfa 147 1.9 JTDm 16V Q2 (110kW) as my daily-drive car, which i rebuilt last August. I renewed the head-gasket, fitted refurbished injectors (which are now about 15.000km old) and cleaned the whole intake. On the engine side, the car now has these mods:
- fixed swirl-flaps
- removed guts of precatalyst
- removed guts of DPF, the main cat is still in to prevent boost creep
- Novitec duplex silencer
- remaps (Tomfile1 and Tomfile2)
Some other mods were also fitted, including powerflex all around, strut bar in the front, Eibach springs and dampers and custom camber-correction bushes for Powerflex bushes.
I started out with the EGR-Delete and a remap to 365Nm (referred to as "Tomfile1"). After that, i removed the guts of the precatalyst (the shell needs to stay in place in case i get pulled over. The only option for fitting another downpipe is to fit it inside the existing precat housing) and tried to measure the car with my obd-dyno. Please be aware that the numbers on the dyno-chart may be way off. I'm using it just to measure the impact of the individual mods.
Because the clutch slipped at WOT between 2000 and 2600 rpm and strong vibrations occured, i got another remap, which has lower IQ between 2000 and 3000 rpm but increased power output on the top end. (referred to as "Tomfile2") With this remap I also deleted the DPF. The slipping clutch is better now. After removing the DPF i noticed a lot of black smoke when i floor the throttle in low rpms. Once the Turbo has spooled up, the smoke is gone. I guess that is normal?!
I still have to do a proper 6th gear log once i get a better traffic situation here.
My goal is to get the most out of the stock engine while maintaining reliability and keeping it smokeless. I'd like to be able to reach a topspeed of 230 km/h. Therefore, i reckon i would need about 200bhp.
I think there are some mods which could be fitted in the future and with your help, i'd like to decide what to do first.
As the requirements to pass the MOT in Germany are quite strict, i cannot do visually obvious mods without paying a ton of money to pass the MOT. Fitting a custom 2,5" exhaust would cost 500€ just to have it tested by the officials, in addition to parts and labour. An obvious turbo upgrade will probably cost even more to get it officialy certified.
During my logging-runs i noticed that my intake air temperature is getting quite high. If I go WOT, once I hit 4000 rpm on 4th, 5th or 6th gear my IAT is already at 70°C (ambient 23°C) and it stays there until i go slower again. Somewhere i read that 10 degrees of reduced intake air temperature can result in 3% power gain. So to increase my topend power, i thought about installing an FMIC or a waterspray system for the stock SMIC. The question is: How much better will an FMIC perform compared to the stock SMIC with waterspray? The cost for both systems is about the same, except i have to get an official approval after fitting the FMIC. And most important: Will colder intake air really result in higher power?
I have read some threads in this forum (including the great threads by JS,yan.ko,tribesman and many others) concering a turbo upgrade. The problem is, that, if i decide to upgrade the turbo, i need something that looks quite like the stock GT1752v. So a GT2256v from a 2.4 JTD will probably be too big to fit under the heat-shields. With the GTB2056 it is probably difficult to fit the downpipe inside the stock cat. I also read that the stock turbo is good enough for 200bhp and could bear up to 1,8 bar boost, what other mods would be needed to reach that figure? Is this the upper limit or is the turbo still reliable at that point?
Currently I am running 1,6 bar boost and IQ 85 mm^3/i is it possible to still gain something via software or is a hardware-upgrade immient?
Would WM-Injection make sense on this state of the engine? This is something i could easily hide and if i look at JS JTD's 147, it gives quite a big performance boost. Im wondering if i push the turbo into the area of overboost/boost-creep from the added exhaust gas as a result of the WM-Injection?
So to sum up my questions (TL;DR):
- FMIC or SMIC+Waterspray to reduce intake temperature?
- How much more IQ can the stock injectors handle at 1750 bar?
- Which Turbo will i be able to "stealth"-fit (not necessarily bolt-on) and provides a decent performance upgrade? GTB1756V? Hybrid?
- When is a bigger exhaust necessary?
- Can i remove the main cat and still prevent boost-creep with the stock turbo?
- Does WM-Injection currently makes sense?
- Any other ideas which i maybe haven't thought of yet?
I'm looking forward to your suggestions and opinions.