Cam upgrade

[MitsuE95GST]

I have some 1G 90 5sp turbo cams, that I want to put in my 95 GST. I know they are an upgrade but what one is an upgrade? The intake cam or the exhaust cam?

 

[cmc]

Hey, did I send you a 14b last month?

 

[allturbo]

both of them

 

[MitsuE95GST]

You sure did CMC, thanks dude, I think i'm going to have to buy a rebuild kit for it though no biggie. Thanks allturbo I was'nt sure if there was a difference in only on or the other.

 

[Bohrn]

is the 90 an upgrade for only the 2G cars or the other 1G cars as well? I ask because there are several differences between the 90 and the later ones. Usually not upgrades tho...

 

[cmc]

Man, all I did to mine was take it apart and clean the carbon off of it, then replace the bearings, and I'm getting full 20 psi(I did once, but run at 12, then flip up to 18 w/ the profec.) Mine was in the same shape yours is(really mine was a little worse when I began) But I cleaned it up and did the bearings, and Bam!! A nice turbo. You might want to try this before you spend alot of money on it!

 

[MitsuE95GST]

Bohrn, i've heard there are several different levels of performance from differenct cams. I guess the 90' GST/GSX manual had the best from all years/models then there was the 1G automatics, then 2G manuals, 2G autos, then there was the 1G NT. If anyone else knows better than let me know.
Hey CMC where did you get the bearings from?

 

[97GSTAT]

2G A/T and M/t is the same. Everything on a 2G is the same except the tranny.

 

[cmc]

I took the bearings to napa, and they hooked me up!

 

[MitsuE95GST]

97GSTAT your right thanks.

 

[BatmanGSX]

'90 cams are the worst 1G cams and I have heard that they are actually worse than 2G cams.

 

[allturbo]

Here are the specs from the dsm cd manual (cam height in mm).

90:
Int- 35.493 Exh- 35.493 (turbo m/t cams)

93:
Int- 35.49 Exh- 35.49 (turbo m/t cams)

95:
int- 34.91 Exh- 34.91


This only tells max height so you really can't tell if the 93 cam is more agressive than the 90 or not.

 

[BatmanGSX]

From what I understand, the 1Gs got progressively more agressive every year. There are other important specs besides lift. Overlap, lobe center, duration, etc. I just don't know what they changed each year. Obviously not lift.

 

[allturbo]

]

There are other important specs besides lift. Overlap, lobe center, duration, etc

Exactly, the shop manual doen't tell anything about the cam profile other than height, but I would image that the 90 cams would be an upgrade to 2G's. Can anyone shed some light on this? I'm swapping out my 2G cams for some 1G's (not sure which year) so I hope I won't be losing power

 

[larryd]

from RRE

"The 1G cams have .010" higher lift. and are an upgrade by themselves. "

it doesnt say what years.. but it was talking a 1g vs 2g

 

[NDgsx]

Originally posted by allturbo
]

Exactly, the shop manual doen't tell anything about the cam profile other than height, but I would image that the 90 cams would be an upgrade to 2G's. Can anyone shed some light on this? I'm swapping out my 2G cams for some 1G's (not sure which year) so I hope I won't be losing power

I wouldn't bother putting 90 cams in. They have a shorter duration than the later 1G cams. I have no idea what type of duration 2G cams have though.
Even though the 90 cams have more lift, they MIGHT not actually make more power.

Quinn at www.crco.com, who is the only person I know of that has done any measurements of stock cams, recomends the 93 or 94 cams over any other year. He said they have longer duration and if I remember right shallower ramp angles.

 

[allturbo]

Unfortunately I have to put the 1G cams in. When my timing belt broke recently it put some nasty scratches on the some of the cam lobes. The cams came from a JDM head I think. On RRE's page for head swaps they say that 92 heads and up have better coolant passages between head and block compared the older one's. Does anyone know if this is visible or is the passages internally better? If it's visible then I must have 92+ cams since the passages look identical to my 2G head.