Turbo

The stock unit is a Mitsubishi TD06-17C-8cm2 with a stock boost pressure of 14.5 PSI. It's rated 550CFM. You can see on the compressor map below, that you have a ~3 PSI of headroom to raise the boost. There is no point to push it toward this, since it out of the acceptable efficiency range. You'd rather generate a lot of heat.



Just for clarification the fastest Syclones with stock turbo cover the 1/4th mile around 12.3-12.4s. I know it's sounds good, but it's not so easy. Requires a really healthy truck and a lot of tuning. Typically a Syclone with a stock turbo, untouched engine and tranny, some mods could run around 13s flat. * If you want step further than this you have to upgrade the turbo. I've to add here, that before you do this you should do some safety mods, like upgraded fuel pump, adjustable fuel pressure regulator and a fuel pressure gauge. Also replace your fuel filter. The stock system barely could keep in line with the stock turbo on stock boost levels. My upgraded fuel pump came from Ron Gregory at Auto Performance Engineering, and it's a Walbro 255 ltr/hr high pressure unit. The SyTy's use an in-tank pump and this pump is perfectly fits into the stock location. There are some companies out there selling external fuel pumps, but I not recommend them. They are quite noisy and should require some fabrication to mount. The above pump could keep up some serious ponies. My AFPR came from KB. It's a billet aluminum one. You can get these units from several other places, we are using the same units as the Buick TR's and GN's. One remark here. Don't try to modify your original regulator. Won't do any good. * So, back to the turbo upgrade. One of the most popular ways is an upgraded Mitsu unit with a TD06H-20G compressor side. It's rated as a 650CFM turbo. On the turbine side you can choose from 10cm2, 12cm2 or 14cm2. With the 14 you should change to a higher stall TC too. Check my tranny page for more info on TC's. With this upgrade you can pick up and additional 0.5s on the 1/4th. This turbo is a direct bolt in, but will go out of steam around 20 PSI like the stocker. The compressor map of this turbo can be seen below.



* Do you wanna step further? I want(ed) to. There are several ways to choose from. There are some KB and ATR units. I don't know too much of them, but they are seem to be Garret units. The Garrets has a quite wide range to cover all of your needs. You will need some fabrication and/or adapter plates to make the fit, but it can be done and has been done by others. * Now, thanks GOD a company called Precision Turbo & Engine (PTE) developed and recently released a combo kit for the SyTy's. It consist of the turbo itself, a 3" downpipe, high flow cat and an integral wastegate. It's around $1600 and could be a TE44, PT51 or PT52 turbo.



They also offer five stand alone turbos 44, 51, 52, 54, 60. The 60 is a Garett unit. They don't rate their turbos by CFM, but by HP. The respective numbers which these turbos could support are 565, 585, 600, 620 and 580. These numbers seems to be a bit high to me, though. Maybe you can reach them with some serious boost level, but this would indicate engine mods as well. According to other guy's experience and some calculations a PTE44 could work with the stock converter, and could make a Sy to cover the 1/4 around mid 12's. Above this you will need the a higher stall converter for sure preferably a 9/11 from Brian Hartman (see my tranny page). The PTE51 and PTE52 could drop you into the 11's zone, but I'd use larger injectors here to be on the safe side. No large boost for sure with the stock injectors! With cool heads (I mean the one sitting on your neck) these turbos could live with the stock motor for a long time. * An other option, which I finally choose, is to go with a P52 turbo with Mike Lee's downpipe which also host an Innovative Turbo Systems external waste gate.


The down pipe is 3" with two 1 3/4" pipes to and from to the WG. The internal WG has been removed from the PT52 and the smaller diameter pipe connects the WG hole on the turbo's exhaust housing to the external WG. The advantage of this setup over the PT downpipe? Well, maybe better potential of the external, and a bit better boost control. On the other hand the Ultimate can't control boost anymore. * Let's see the compressor map of the PT52, which is using a Garett T04B-60-1 compressor side.



You can compare this to the above maps. This turbo will go out of steam around 16-18 psi, which is more than most 4.3 turbo can handle. * I also had to fabricate a new turbo-to-IC pipe too. It has been made from three 90 degree SS elbows, welded together and polished. I used Samco silicon couplings (in red of course) and T-clamps from Summit. The pipe has a 52mm ID.



* There are larger turbos out there as well for example the Precission 70 series including 72 which seems to be a favorite pickup for the "all out effort" guys. These larger turbos are typically requires the deletion of the air conditioning and would need some built engine, stand alone engine management, built tranny etc. Not my focus at this time. * Anyway I gonna gather more information on turbos in the future for sure.

Boost control

The stock boost control based on a solenoid. It has three vacuum ports. One vacuum hose is coming from the compressor side of the turbo, this is the passenger side. An other vacuum hose goes from the upper driver's side port to the wastgate actuator. The third port is a vent port.


These solenoid controlled by the ECM to trick the wastgate actuator. The stock wastgate actuator has a spring in it which gives a base boot of 10 psi. This is where the actuator opens out the wastgate completely. With the rapid opening and closing the vent port of the solenoid the ECM could make the actuator believe that it sees only 10 psi when the actual pressure is 15 already. This is the basic stuff. With a properly tuned truck you can get quite decent boost control that way even up to 19-20 psi. If you have a problem with the spool up or boost level and ruled out all the usual stuff, like ignition, vacuum leaks etc, you can try to adjust your WG's arms. There is a rod coming out from the actuator with an eylet on its end. This eylet connected to the WG's arm. With loosening the nut holding the eylet you can adjust the length of the rod by half turns to turn the eylet itself. If you shorten it, you will get better spool up and/or higher boost (depends on your chip). The factory specs is 7/8 overlap between the eylet and the WG's arm. * The PTE setup are using the same way to control boost. The advantage of this, that you can still use the Ultimate like chips to change your boost levels. * There are quite a few other ways to control boost. You can get an actuator with a stronger spring (or use an outside helper spring) to raise your base boost. You can get rid of the solenoid with this, but you won't be able to change your boost levels on the fly with out some electronic boost controllers. There are quite a few guys using external WG's even with the stock turbo (stock WG welded shut). Externals can't be controlled with the solenoid, so you have to use an electronic or choose your boost level and stay there. * There are still other forms of boost control. The most simples are bleeder valves, venting out a specific amount of air, adjustable by screws. I'd not suggest them, because setting the boost leves a pain in the but and they are very sensitive to the temperature changes. You won't get the same boost on a cold day. Pretty anoying. I'm playing with an other type of manual control however for some time. It's called a grainger valve. It's just a nickname for a simple ball & spring check valve with adjustable spring tension. I can get pretty decent results with it. If you check my 2002 Perf page, the latest run there were with this valve. I can't say this is the ultimate solution, but it's cheap and pretty reliable. However I've problem to go over 16 psi with it with my stock actuator. I can reach that kinda boost, but only with the adjustment of the WG rod. On the other hand if I adjust the WG rod too tight to get higher pressure, spikes will come, so I stayed with 15 psi so far.


* On the high end there are the different kind of electronic controllers. The simpler ones using the same type of solenoids (or even the stock one) as our original boost control does. The more complicated ones has their own pressure sensor and adjusting the control based on its feedback. I don't have hand on experience with these, but will gather some information soon. * Please note that the above recommendations based only on my experience, so they could be wrong. *