Van
03-12-2001, 05:49 PM
I got and installed these parts at the same time, so I'm just gonna do one review of them and separate some facts about the two. :D
I bought both parts on sale from Forced Performance, ported for $422. This price included all gaskets necessary for re-install except the DP gasket.
The porting by FP on the exh. mani., was just done in the collector area, FP did a nice job. I knew in advance that the runners would not be ported when I made the purchase, so I ported the exh. runners to the gasket myself. The porting on the O2 hsg. by FP was more extensive, very nice IMO. I still did a little more porting myself, just to remove some more internal casting roughness I found.
FP's service was excellent, Robert was straight up and told me he was buried in porting work and the shipping would be a little delayed. No problem by me. I've had nothing but good service and experiences with FP.
Got some tech. facts for you that are interested:
I did some internal volume tests and measurements on the parts and found some interesting things.
stock 1g O2 hsg. = 420ml (milliliters)
ported EVO3 O2 hsg. = 510ml
1g O2 hsg., main exh. inlet has a 55mm opening
ported EVO3 O2 hsg., main exh. inlet has a 65mm opening
1g O2 hsg., main exh. outlet has a 55mm opening
ported EVO3 O2 hsg., main exh. outlet has a 65mm opening
The EVO3 O2 hsg is huge, it has 90ml more space for exhaust flow over the stock 1g O2 hsg. Its internal passages are alot smoother in design also. It is much beefier, the O2 sensor sits in the stock location for a 1g, the stock heat shield will bolt back up correctly. However, the angle of the EVO3 hsg. DP flange is different, your DP will probably need a flex section to fit properly. It twists the DP towards the transfer case and rear driveshaft on an AWD. The stock DP clamp by the oil filter will still work though. Also, the DP studs are set wider apart, your DP flange will need slotted bolt holes to accomodate this. Seems like most good DP's have slotted flanges on 'em. My Buschur DP has a slotted flange and a flex section. I replaced all the O2 hsg. to turbine hsg. bolts and the stud with 10.9 grade, high strength alloy bolts. You'll have to grind a little on the outside of the O2 hsg. in the "niche" where the stud was to get the bolt in. Very easy, not too much material has to be removed there.
I did some internal volume tests and measurements on the exh. mani's too:
stock 1g exh. mani. = 768ml
stock 2g exh. mani. = 828ml
ported EVO3 exh. mani. =805ml
stock 1g exh. mani. has a 55mm collector opening
ported EVO3 exh. mani. has a 60mm collector opening
If you are like me you're thinking WTF, right about now! Me being the optimist, I'm hoping that the EVO3 mani. is the better of the three. This isn't necessarily true, only a flow bench test would prove one better. There could be wasted space in the 2g mani. that doesn't flow as well, who knows...
The EVO3 exh. mani. has the beefy construction of the 2g exh. mani. and the stock 1g heat shield bolts right back up in the stock locations.
Install wasn't really too bad... I decided to upgrade all nine studs with the 10x1.25mm studs. Not exactly easy, but worth it now, while it's all out, IMO. You can get these studs at NAPA for $5 a pack with 2 studs and nuts in each pack. I also replaced the mani. to turbine hsg. bolts and the stud with 10.9 grade, high strength alloy bolts. They cost about $4 ea.
These mods aren't about bang for the buck. It's all about flow, the turbo spools right now from a stop! (I did port my stock turbine hsg. to match the openings in the EVO3 parts too.) The top-end seems to pull alot easier, the exhaust is abit quieter while cruising too, but a little louder at wot. It also dropped my boost about 1 psi, with no other changes. I suspect that less overall restriction caused this. Not really a problem, just something I noticed. My egt's dropped some too, about 50-75 degrees F. I expected this as the exhaust can flow better and spend less time saturating the egt probe. Which also responds a little faster now too. From cruising at 3000rpm to wot, no boost, in fourth gear, the turbo hits 19 psi in under 2 seconds easily, at 3200rpm. A bit faster than before the EVO3 parts were installed, with alot more neck-snapping authority!
I ended up having to wrap a piece of metal strapping around the dp from the first exhaust hanger bracket (by the dp, under the car, on the frame,) to pull the dp and cat off of the rear driveshaft. I also did the same strap on the first exhaust bracket for the cat-back. Just to make sure the "twist" was taken out evenly and it didn't end up breaking something else. Not hard, just a little hassle. Worth it IMO!
[Edited by Van on 03-13-2001 at 05:51 PM]
I bought both parts on sale from Forced Performance, ported for $422. This price included all gaskets necessary for re-install except the DP gasket.
The porting by FP on the exh. mani., was just done in the collector area, FP did a nice job. I knew in advance that the runners would not be ported when I made the purchase, so I ported the exh. runners to the gasket myself. The porting on the O2 hsg. by FP was more extensive, very nice IMO. I still did a little more porting myself, just to remove some more internal casting roughness I found.
FP's service was excellent, Robert was straight up and told me he was buried in porting work and the shipping would be a little delayed. No problem by me. I've had nothing but good service and experiences with FP.
Got some tech. facts for you that are interested:
I did some internal volume tests and measurements on the parts and found some interesting things.
stock 1g O2 hsg. = 420ml (milliliters)
ported EVO3 O2 hsg. = 510ml
1g O2 hsg., main exh. inlet has a 55mm opening
ported EVO3 O2 hsg., main exh. inlet has a 65mm opening
1g O2 hsg., main exh. outlet has a 55mm opening
ported EVO3 O2 hsg., main exh. outlet has a 65mm opening
The EVO3 O2 hsg is huge, it has 90ml more space for exhaust flow over the stock 1g O2 hsg. Its internal passages are alot smoother in design also. It is much beefier, the O2 sensor sits in the stock location for a 1g, the stock heat shield will bolt back up correctly. However, the angle of the EVO3 hsg. DP flange is different, your DP will probably need a flex section to fit properly. It twists the DP towards the transfer case and rear driveshaft on an AWD. The stock DP clamp by the oil filter will still work though. Also, the DP studs are set wider apart, your DP flange will need slotted bolt holes to accomodate this. Seems like most good DP's have slotted flanges on 'em. My Buschur DP has a slotted flange and a flex section. I replaced all the O2 hsg. to turbine hsg. bolts and the stud with 10.9 grade, high strength alloy bolts. You'll have to grind a little on the outside of the O2 hsg. in the "niche" where the stud was to get the bolt in. Very easy, not too much material has to be removed there.
I did some internal volume tests and measurements on the exh. mani's too:
stock 1g exh. mani. = 768ml
stock 2g exh. mani. = 828ml
ported EVO3 exh. mani. =805ml
stock 1g exh. mani. has a 55mm collector opening
ported EVO3 exh. mani. has a 60mm collector opening
If you are like me you're thinking WTF, right about now! Me being the optimist, I'm hoping that the EVO3 mani. is the better of the three. This isn't necessarily true, only a flow bench test would prove one better. There could be wasted space in the 2g mani. that doesn't flow as well, who knows...
The EVO3 exh. mani. has the beefy construction of the 2g exh. mani. and the stock 1g heat shield bolts right back up in the stock locations.
Install wasn't really too bad... I decided to upgrade all nine studs with the 10x1.25mm studs. Not exactly easy, but worth it now, while it's all out, IMO. You can get these studs at NAPA for $5 a pack with 2 studs and nuts in each pack. I also replaced the mani. to turbine hsg. bolts and the stud with 10.9 grade, high strength alloy bolts. They cost about $4 ea.
These mods aren't about bang for the buck. It's all about flow, the turbo spools right now from a stop! (I did port my stock turbine hsg. to match the openings in the EVO3 parts too.) The top-end seems to pull alot easier, the exhaust is abit quieter while cruising too, but a little louder at wot. It also dropped my boost about 1 psi, with no other changes. I suspect that less overall restriction caused this. Not really a problem, just something I noticed. My egt's dropped some too, about 50-75 degrees F. I expected this as the exhaust can flow better and spend less time saturating the egt probe. Which also responds a little faster now too. From cruising at 3000rpm to wot, no boost, in fourth gear, the turbo hits 19 psi in under 2 seconds easily, at 3200rpm. A bit faster than before the EVO3 parts were installed, with alot more neck-snapping authority!
I ended up having to wrap a piece of metal strapping around the dp from the first exhaust hanger bracket (by the dp, under the car, on the frame,) to pull the dp and cat off of the rear driveshaft. I also did the same strap on the first exhaust bracket for the cat-back. Just to make sure the "twist" was taken out evenly and it didn't end up breaking something else. Not hard, just a little hassle. Worth it IMO!
[Edited by Van on 03-13-2001 at 05:51 PM]