What is best bang for buck improvement on a 3.6 rebuild?

[JonT]

Chip?
Cams and chip?
Cams, valves, chip?
ITB, cams, valves, chip, motec?

Where is the line where the hp/$$ goes exponentially up for increases?

Still planning my rebuild and wondering if my current plan for supersport cams and a Wong chip is the way to go for a mild performance upgrade? Should I do the valves too?

I'm not trying to blaze a new trail just build a reliable, safe, street/DE engine with proven performance improvements. And yes I've been doing search after search...

Thanks

[Joe Bob]

Describe your rebuild. Top end or total. Do you have smog restrictions, what is your budget, how thick is your wallet?

Depending on visual inspection....valves are always a good idea. ITBs and cams are a great upgrade. Free flowing exhaust to breathe. Do you need heat?

[DonDavis]

I would focus on SERIOUS oil cooling. Upgrade to the best for your intended use and budget.

After that, steering wheel, driver's seat, brakes. To start with. ;-)

*edit*
my bad, I misread the title. Thought it was an early 3.6 conversion. Wow, I was way off.

[Joe Bob]

I was assuming that with a 3.6 conversion that his cooling needs were met. But still a good idea.

I went with Elephant finned lines, a Carrera cooler in the passenger well and a MOCAL in the nose...a single external cooler didn't cut it. I later added a SPAL fan for bumper to bumper trips.....it's kicked on once.

[Bill Verburg]

Originally Posted by JonT

Chip?
Cams and chip?
Cams, valves, chip?
ITB, cams, valves, chip, motec?

Where is the line where the hp/$$ goes exponentially up for increases?

Still planning my rebuild and wondering if my current plan for supersport cams and a Wong chip is the way to go for a mild performance upgrade? Should I do the valves too?

I'm not trying to blaze a new trail just build a reliable, safe, street/DE engine with proven performance improvements. And yes I've been doing search after search...

Thanks

there's no line just a slippery slope that gets extremely steep. And on who is doing the labor

best of course will be a GT3 bottom end w/ custom pistons and cams ala Singer, Motec etc. 400+ hp for $40K+

when I did mine I built to 3.8RS spec, w/ just RS cams, RSR p/c, RS heads, chip I'd guess ~$20k+ for 300+hp

You can skip th p/c and save a bunch, just go w/ RS or SS cams and a chip, maybe ~$10-15k for a bit under 300hp and a bit less torque than a 3.8

for extreme track use I'd use Pauter rods at a min, on a stock or 964 crank, and ss cams(or may be a little happier) w/ solid lifters

it'd be great to raise the rev limit but the intakes, rods, crank oiling, heads are all limiting factors. So the best bang is to use stockish rev limit and stockish components. options 2 & 3 above

[Bill Verburg]

oh I forgot to add that I wouldn't get too crazy if this was going to be used w/ a 915. I found that the 300+hp from the 3.8RS was too much for a late 915. You can of course spend a bunch to beef up the 915 but in the end it's a losing battle

[Joe Bob]

Bill brings up a good point. WEVO makes a lot of good upgrades. The intermediate plate support is the best street upfix.

[petevb]

Originally Posted by Bill Verburg

when I did mine I built to 3.8RS spec, w/ just RS cams, RSR p/c, RS heads, chip I'd guess ~$20k+ for 300+hp

You can skip th p/c and save a bunch, just go w/ RS or SS cams and a chip, maybe ~$10-15k for a bit under 300hp and a bit less torque than a 3.8

I went between these two with one of my motors. Solid lifter SS cam, bigger RS valves, springs, retainers, rod bolts etc to let it rev but left the displacement at 3.6. 295 at the wheels on the 100 octane chip, about 285 on 91 octane. Pretty good bang for the buck as far is it goes I thought.

This was on a VRam; on the 100 map torque came on a bit sooner that the full 3.8RS and it made a bit more power up top, but it was down on torque in the midrange. On 91 Octane it was slightly behind the 3.8 RS everywhere, but nearly identical peak power up top and it held that power for 500 rpm longer than the RS (probably due to the solid lifter cam vs hydraulic).

Edit: all of the above assumes you do headers and a chip. Especially on an early 3.6 that's the only thing that might actually qualify as "good" bang for the buck

[beamonk]

I went back and forth with my 95 motor also. I communicated with Bill and Steve Weiner and Brady at the 901 shop. all of these guys gave great advice but for my purposes, hot street/ 5 or so track days a year, I decided as follows. I figured as with alot of motors that breathing is important, so I went with George's euro headers, sent my heads to Xtreme heads in Fla. Full valve job with 52mm intakes and larger exhaust. All kinds of head prep goodies, new springs, ceramic coating on pistons, heads, friction coatings on bearings and pistons. SS cams and rockers by John Dougherty and ARP rod bolts. i spoke with Steve Wong about a custom chip and will do a cooler and Wevo tranny plates. i figure that in Alabama cooling and flow will be the key to longivity so appropriate oil cooling will be added. This is the best bang for the buck for me. I can't say enough for the good advice from bill, Steve, Steve, John Brady and Bill at Xtreme. All great guys and getlemen with their advice and knowledge. I can't wait to finish it! figure out your realistic usage, that is the most important. I want longivity and lack of constant tinkering.

[JonT]

More details:

Engine is an early 964. Rod bearing #2 was shot and it looks like the crank can be repaired as well as any rod damage. No other engine damage so it looks like I caught it early.

I'd like to keep things factory but I'm wondering if SS cams and a WONG chip alone will make much improvement. Another Pelican reports 275 rwhp with this setup which is certainly a nice improvement. Will larger valves be a worthy addition? Will I need to replace intake and exhaust? My exhaust is 993 headers.

My current plans are:

repair crank and rod
replace rod bolts ARP
replace head studs
clean up factory heads, cylinders, valves, and pistons
993 supersport cams
Wong chip
replace rings

Budget? 10k

[Joe Bob]

You'll eat 10K up pretty quick. Depends on how much work you do yourself. Machine shops aren't cheap. Valves need to breathe, and intake mods, and cams.

Depends on your use. You can easily dump another 10K to chase a few HP. I'd leave it close to stock as possible and do the minor mods you mentioned.

[Bill Verburg]

Originally Posted by JonT

More details:

Engine is an early 964. Rod bearing #2 was shot and it looks like the crank can be repaired as well as any rod damage. No other engine damage so it looks like I caught it early.

I'd like to keep things factory but I'm wondering if SS cams and a WONG chip alone will make much improvement. Another Pelican reports 275 rwhp with this setup which is certainly a nice improvement. Will larger valves be a worthy addition? Will I need to replace intake and exhaust? My exhaust is 993 headers.

My current plans are:

repair crank and rod
replace rod bolts ARP
replace head studs
clean up factory heads, cylinders, valves, and pistons
993 supersport cams
Wong chip
replace rings

Budget? 10k

Yes, all the above will makes for a nice sub 300hp motor. For a little better breathing change to 993 heads, for a little better change to RS valves(or ss or Ti equivalents)

W/ stock Motronic & plastic intake you will be limited to <7k rpm , w/ Motec you could extend that and get mid 300 hp but that is a lot more $

[petevb]

Originally Posted by JonT

I'd like to keep things factory but I'm wondering if SS cams and a WONG chip alone will make much improvement. Another Pelican reports 275 rwhp with this setup which is certainly a nice improvement. Will larger valves be a worthy addition? Will I need to replace intake and exhaust? My exhaust is 993 headers.

My current plans are:

repair crank and rod
replace rod bolts ARP
replace head studs
clean up factory heads, cylinders, valves, and pistons
993 supersport cams
Wong chip
replace rings

Budget? 10k

Your valves are smaller than the 993 VRam on both intake and exhaust. Going to the RS (or bigger) valves (will likely require some pocketing of the pistons with a good cam) will probably find you 15-20 hp but likely blow your budget.

If memory serves, and this is going back a while, the 964 rods were not as good as the 993.

[petevb]

Originally Posted by Bill Verburg

W/ stock Motronic & plastic intake you will be limited to <7k rpm , w/ Motec you could extend that and get mid 300 hp but that is a lot more $

What's the bottle-neck there, the intake? My 993 VRam pulled cleanly and made power through 7300...

[Bill Verburg]

Originally Posted by petevb

What's the bottle-neck there, the intake? My 993 VRam pulled cleanly and made power through 7300...

964 ports are 41.5/38
993 are 43/39

964 use 49/42.5 valves 9mm stems
993 non vram use the same but w/ 8mm stems
993 vram use 50/43.5 w/ 8mm stems
993RS use 51.5/43.5 w/ 8mm stems

The plastic intake is good but to make hp the 964 barn door air meter needs to go, w/ Motec they use MAP sensors and rpm and throttle position to meter the air very similar to what they used on the 993Cups which are all non vram w/ plastic manifolds

the 993 MAF is much better oem and can get away w/ a chip change

[Bill Verburg]

Originally Posted by petevb

Your valves are smaller than the 993 VRam on both intake and exhaust. Going to the RS (or bigger) valves (will likely require some pocketing of the pistons with a good cam) will probably find you 15-20 hp but likely blow your budget.

If memory serves, and this is going back a while, the 964 rods were not as good as the 993.

964 rods are actually quite good, they are the same as used in 3.0 and 3.2 SC/Carrera and 3.3 turbo. They are also sometimes used w/ GT3 crank. They were also use in 993Cups

993 rods are fine for stock rpm but have a reduced bearing area that is considered questionable for best results.

[fbarrett]

Think outside box: put $5K into making it cool better and be reliable, then spend the rest of your budget on suspension, good driver's schools, and practice. Power isn't everything.

Frank

[beamonk]

That is why I decided to go with the cooling ceramics, etc. I don't want to pry my checkbook open for this again! Make sure you send your crank to a good crank shop. I think there is one in Colorado that has a good reputation or get another one. I am sure someone can chime in on a good crank shop.