Tsunamix
Active Member
- Joined
- Nov 17, 2008
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- VT 2
Hi Folkses.
First a word of warning - do NOT build the same engine combo I have, unless you have also improved your suspension. This is a serious word of warning. Theres a combination of circumstances and action that would catch a novice by surprise and cause heartache if not grief. Read on for the details but be warned - suspension improvements are NECESSARY for safety from here in.
I drive a VT2 1999 ecotec six, auto. 18 months ago I put a set of MACE 1.98 rockers on it, then a cheap sports exhaust. then I added King spring Low's (not super low), Boges gas sports struts and shocks, 32mm front sway bar, 22mm rear, full nolathane bushes all round, new factory hydraulic engine mounts, slotted brake rotors all round, GSL's police spec pad's, and run on 235/45 R17 Falken FK452's.
Everythings been chosen rather carefully. The Falken's are a wheels tyre test winner, the Boges brand is used by BMW and Mercedes as factory items, and so on. I spent my money on the suspension and brakes before doing much else.
Next was a gearbox rebuild with a beast stally and bands - factory RPM on the stall. Beast do carbon fibre bands so they should last a while. A transgo stage 2 shift kit and corvette servo piston were added. Drives wonderfully. The beast stally locks up solidly, there is no give in it. So if you get up it, it amost feels like an extra gear change when it locks up.
Now for the new additions. A MACE under plenum 12mm spacer, and oversive throttlebody and a chip.
Of course, being a something of a perfectionist I din't read the instructions - I can't read them unless there in swedish or chinese anyway, and since MACE is Australian they were usless too me. Actually they were dead simple. There is only one point to remeber about installing all 3 pieces - the blanking bplug goes into the vacuum hose with the elbow at the throttlebody.
Easy enough really. strip off the plenum, taking care not to drop sh*t down the runners. Leave the injectors clipped to the fuel rail, just remove the wire clamp that holds the black elecrical connectors on. Remove the fuel rail and injectors and remount with the spacer bolts.
Clean the lower plenum face in the valley, and add a very thin skin of sensor safe silastic - conveniently supplied by MACE with spacer kit. More is definitley NOT better. use this thin skin to tack the spacer in place. Clean the sensor o rings and add a little bit of reassembly lube. Like the Penrite one I had left over from MACE's rockers. Clean the mating face of the plenum and add a very thin skin of silastic. Do NOT fill the vent channels between the O-rings. Gently replace plenum in position. Gently wiggle the injectors until they are all seated properley. Remove the factory plenum mount bolts and replace them with the (Grade 8.8 High Tensile!) bolts supplied. Finger tighten them. wiggle everything to make sure its seated. this is important - stuffing an injector o-ring will make vaccum leaks. Tighten and refit everything.
Throttlebody - be careful of the plastic clip that holds the cruise control cable onto the nipple pin. It's often dead due to heat aging.
removing and refitting the new throttlebody was dead simple. Read the instructions that I didn't read and it's even easier.
Mount the mace chip. Have a torx bit screwdriver handy
Disconnect battery for 30 seconds. Reconnect, start the engine, hold at 2000 rpm for 2 minutes. stop engine and restart. Should be good to go.
I found that somewhere along the line, the exhaust gas recirculation pipe fitting had deformed the pipe and I was getting an vaccum leak into the manifold, behind the throttlebody. Made for a slightly insonsistent idle. I removed the recic ipe and blanked it off with a 20c piece and some silastic. I also clamped (flattened and bent double) the end of the recirc pipe until I can get a new one. This pipe is thin and could be bent with tweezers.
Problem solved - but this basically makes the engine illegal as it would fail emissions test. Since today's sunday I will have to get a new one on Monday from Holden.
Ran the engine at idle for a while to get a little heat into the engine, a dribbled a little sewing machine idle on the injector seats to make sure there were no more vacuum leaks (it will drink the oil if there is).
I noticed without the recirc attached, and the spacer in place, that the plenum temp was stone cold (air temp) even with the engine at operating temp.
Jumped in and went for a drive. I drove from Strathpine to Samford and back (northern edge of Brisbane). Winding twisty hilly roads, speed limit of 80 mostly. 20 minutes out, stop and check everything (plenum still stone cold) and came back. Got home, checked everything out again and this is my thoughts :-
Plenum was still stone cold !!!!!! after the run (about 45Km all up plus stuffing around) I was leaning on the plenum checking my handiwork on the 20c piece and it was genuinley cool to the touch.
Important point - On cruise control, the shift pattern for the auto was aggresive. I don't know if thats's part of the memcal programming. Several times it surprised me by changing down 2 gears instead of one, and giving it a solid rev. up to about 3500rpm (This happened on hills, and the road was twisting as well as climbing) . In the wet, that would have broken traction. Part of the issue is undoubtledy related to the stall convertors torque multiplying effect, but unless your suspension is sorted, I could imagine it throwing you sideways a bit in a single wheeler diff equipped car, in the wet. If the Memcal has something to do with shift points, then between it and the way I have built my gearbox, it's too aggressive for the cruise control.
There is definitley a boost to low down torque. it will catch you by surprise the first time you touch toe to accelerator. I have a loose draw in the dash under the stereo which used to occasionally come out under hard acceleration. Now it's every time I come off the mark.
I think economy may be improving with it. You certainly need smaller throttle openings to achieve the saem acceleration. The electronics are telling me that I will get 720 Clicks to the tank if I keep driving that way - which was not all that gentle. Let's wait and see.
the car had a best quarter mile time of 15.72 before today. 3 runs gave me a 15.32, a 15.48 and a 15.44. Solid. This is tested with my iphone's in built accelerometer and a dyno progeam, so It's probably not exact, but i think it's a decent indicator.
Driving normally, you notice more low down torque, but the build in the higher rev's you get is less pronounced. This is because there is less difference now between lower end acceleration and the mid/high range the ecotec has.
It's a decent nett gain in my books. With the advantage of improved driveability as it's not as sluggish down low, and a large improvement in consistency as the plenum air temp has to be more consistent.
I spent less than $500 bucks, and maybe 2 hours getting my hands dirty for an improvement. I get the feeling that now the factory cat is holding me back a bit (I have extractors and a 2.25" sports system), so I think that I will keep the extractors and switch to a 3" with a bullet cat. Yes it's big for a Naturally aspirated system, but I plan to raptor it and it will be fine for that.
In general - its good value.
First a word of warning - do NOT build the same engine combo I have, unless you have also improved your suspension. This is a serious word of warning. Theres a combination of circumstances and action that would catch a novice by surprise and cause heartache if not grief. Read on for the details but be warned - suspension improvements are NECESSARY for safety from here in.
I drive a VT2 1999 ecotec six, auto. 18 months ago I put a set of MACE 1.98 rockers on it, then a cheap sports exhaust. then I added King spring Low's (not super low), Boges gas sports struts and shocks, 32mm front sway bar, 22mm rear, full nolathane bushes all round, new factory hydraulic engine mounts, slotted brake rotors all round, GSL's police spec pad's, and run on 235/45 R17 Falken FK452's.
Everythings been chosen rather carefully. The Falken's are a wheels tyre test winner, the Boges brand is used by BMW and Mercedes as factory items, and so on. I spent my money on the suspension and brakes before doing much else.
Next was a gearbox rebuild with a beast stally and bands - factory RPM on the stall. Beast do carbon fibre bands so they should last a while. A transgo stage 2 shift kit and corvette servo piston were added. Drives wonderfully. The beast stally locks up solidly, there is no give in it. So if you get up it, it amost feels like an extra gear change when it locks up.
Now for the new additions. A MACE under plenum 12mm spacer, and oversive throttlebody and a chip.
Of course, being a something of a perfectionist I din't read the instructions - I can't read them unless there in swedish or chinese anyway, and since MACE is Australian they were usless too me. Actually they were dead simple. There is only one point to remeber about installing all 3 pieces - the blanking bplug goes into the vacuum hose with the elbow at the throttlebody.
Easy enough really. strip off the plenum, taking care not to drop sh*t down the runners. Leave the injectors clipped to the fuel rail, just remove the wire clamp that holds the black elecrical connectors on. Remove the fuel rail and injectors and remount with the spacer bolts.
Clean the lower plenum face in the valley, and add a very thin skin of sensor safe silastic - conveniently supplied by MACE with spacer kit. More is definitley NOT better. use this thin skin to tack the spacer in place. Clean the sensor o rings and add a little bit of reassembly lube. Like the Penrite one I had left over from MACE's rockers. Clean the mating face of the plenum and add a very thin skin of silastic. Do NOT fill the vent channels between the O-rings. Gently replace plenum in position. Gently wiggle the injectors until they are all seated properley. Remove the factory plenum mount bolts and replace them with the (Grade 8.8 High Tensile!) bolts supplied. Finger tighten them. wiggle everything to make sure its seated. this is important - stuffing an injector o-ring will make vaccum leaks. Tighten and refit everything.
Throttlebody - be careful of the plastic clip that holds the cruise control cable onto the nipple pin. It's often dead due to heat aging.
removing and refitting the new throttlebody was dead simple. Read the instructions that I didn't read and it's even easier.
Mount the mace chip. Have a torx bit screwdriver handy
Disconnect battery for 30 seconds. Reconnect, start the engine, hold at 2000 rpm for 2 minutes. stop engine and restart. Should be good to go.
I found that somewhere along the line, the exhaust gas recirculation pipe fitting had deformed the pipe and I was getting an vaccum leak into the manifold, behind the throttlebody. Made for a slightly insonsistent idle. I removed the recic ipe and blanked it off with a 20c piece and some silastic. I also clamped (flattened and bent double) the end of the recirc pipe until I can get a new one. This pipe is thin and could be bent with tweezers.
Problem solved - but this basically makes the engine illegal as it would fail emissions test. Since today's sunday I will have to get a new one on Monday from Holden.
Ran the engine at idle for a while to get a little heat into the engine, a dribbled a little sewing machine idle on the injector seats to make sure there were no more vacuum leaks (it will drink the oil if there is).
I noticed without the recirc attached, and the spacer in place, that the plenum temp was stone cold (air temp) even with the engine at operating temp.
Jumped in and went for a drive. I drove from Strathpine to Samford and back (northern edge of Brisbane). Winding twisty hilly roads, speed limit of 80 mostly. 20 minutes out, stop and check everything (plenum still stone cold) and came back. Got home, checked everything out again and this is my thoughts :-
Plenum was still stone cold !!!!!! after the run (about 45Km all up plus stuffing around) I was leaning on the plenum checking my handiwork on the 20c piece and it was genuinley cool to the touch.
Important point - On cruise control, the shift pattern for the auto was aggresive. I don't know if thats's part of the memcal programming. Several times it surprised me by changing down 2 gears instead of one, and giving it a solid rev. up to about 3500rpm (This happened on hills, and the road was twisting as well as climbing) . In the wet, that would have broken traction. Part of the issue is undoubtledy related to the stall convertors torque multiplying effect, but unless your suspension is sorted, I could imagine it throwing you sideways a bit in a single wheeler diff equipped car, in the wet. If the Memcal has something to do with shift points, then between it and the way I have built my gearbox, it's too aggressive for the cruise control.
There is definitley a boost to low down torque. it will catch you by surprise the first time you touch toe to accelerator. I have a loose draw in the dash under the stereo which used to occasionally come out under hard acceleration. Now it's every time I come off the mark.
I think economy may be improving with it. You certainly need smaller throttle openings to achieve the saem acceleration. The electronics are telling me that I will get 720 Clicks to the tank if I keep driving that way - which was not all that gentle. Let's wait and see.
the car had a best quarter mile time of 15.72 before today. 3 runs gave me a 15.32, a 15.48 and a 15.44. Solid. This is tested with my iphone's in built accelerometer and a dyno progeam, so It's probably not exact, but i think it's a decent indicator.
Driving normally, you notice more low down torque, but the build in the higher rev's you get is less pronounced. This is because there is less difference now between lower end acceleration and the mid/high range the ecotec has.
It's a decent nett gain in my books. With the advantage of improved driveability as it's not as sluggish down low, and a large improvement in consistency as the plenum air temp has to be more consistent.
I spent less than $500 bucks, and maybe 2 hours getting my hands dirty for an improvement. I get the feeling that now the factory cat is holding me back a bit (I have extractors and a 2.25" sports system), so I think that I will keep the extractors and switch to a 3" with a bullet cat. Yes it's big for a Naturally aspirated system, but I plan to raptor it and it will be fine for that.
In general - its good value.
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