Thanks! And tell us a little about your Mercedes...

well, traffic was crazy and the weather sucked last night but I did manage to drive thru my neighborhood in 2nd gear going from 3200-3500rpm. People thought I was nuts. I found out 2 interesting things:

1) temp goes from 196* to 198* within the first 15-20 seconds but stabilizes there. Now I didn't do it for 5 miles/5 minutes as I just didn't have the real estate to pull that off.

2) Why on earth would you even consider running 4000rpm down the road for any period of time? Change the gear ratio ;)

Well, 4000 rpm is 80 in 5th gear. I agree, all these conversions should swap out at least 5th gear.

my conversion with the radiator in front runs 180-190 on hot days on the interstate. but with the 930 transaxle i am only turning 2200 rpms at 70 mph. and my car has a small frontal opening as it is a ruf yellowbird front spoiler and i dont want to cut the opening larger! the engine is a mast motorsports ls7...427 cubic inches..and makes 700 chp!http://forums.pelicanparts.com/uploa...1403792067.jpg

Larry, can you drive down a nice road in a low gear at 4 rpm for about 5 miles and let me know your temp. If we all have hi temps then it is all about gears.

Yan

Does anyone have instructions/photos/video for a g50/01 5th gear swap. I am looking for a real tall gear for highway quiet and low rpm.

Thanks

my tuner also said it sounds like a fuel or timing issue. High rpm and low load needs a decent amount of timing

Already nicely tuned to correct the issue. I think (and may be wrong) that all of the ls setups will get hot around 4000 rpm (especially after 5 to 10 miles) unless they have a large radiator. Tall gears probably solves all the issues and should be a priority in all swaps. These motors like to run with low rpms I think...

Seconded. Setup depending, I keep 34-40° advance in cruising bins. An EGT probe can help dial in a nice, safe burn.

yessir

my Benz cruises down the highway at close to 80mph well under 3000rpm

yan it is rainy in our area. maybe i can make a run later in the week. as a note, i did not use the renegade hybrids radiator. i had the radiator built by griffin which is very close to me. i had it built as large as i could fit into the frontal opening. it is sealed to the sides and to the inner fenders as well as the hood. seems the faster i go the better it cools. probably due to the relatively small opening in the ruf front spoiler!http://forums.pelicanparts.com/uploa...1404053811.jpg

Larry, what size radiator and fan setup did u use? I am not worried about speed with anyone. Gear size totally makes a difference. I am hoping just even going slow at 4000 rpm for say 5 to 10 miles will show the true temps of the car. I know the car gauges are never perfect but hoping you have a computer of some sort hooked up. I use my iphone with Rev2 and a wifi adapter with the obd2 but anything that reads the temp is fine. If someone with a good radiator setup gets hot with high rpms then it really is all in the gears... Thanks!

Yan

I'll chime in on this, I have 3 radiators on my 966 C4S, now C42. I had a taller ring and pinion installed, in 6th gear I'm showing 80 MPH 2,375 RPM . My temp at highway speed never gets over 190 degrees even in 100 degree temps. However my oil gets hot, at the same temps it will go to 260 degrees. Am in the process of looking into an oil cooler.

I noticed that pulling a grade in 95-100 temps that the oil temp rises quickly. I just returned from 4,000 mile trip in the car so I had lot's of time to look at all of this.

Bottom line, unless you're going to drag race your car, I would go for the taller gears, changing the ring and pinion changed all of the gearing, expensive, but well worth it... At 70-80 MPH my car is quieter than with the 3.6 engine, mostly because the RPM's are lower.

Mitch, thanks for chiming in. You have two of your radiators in your front fenders (stock)? Do you have photos of that portion of your setup? I am wondering if I added an additional radiator in a front fender in my 89 911. Would I need to cut anything to vent or are they just naturally vented in the fender and what size are they? Fans? Or would a center front radiator require or work with a stock valance with a cutout of the valance (this being just an extra radiator).

I do plan on getting the taller 5th gear but I know I must be very close to a fully working setup already and with slightly extra cooling I may be able to maintain temp at any rpms. Not that I plan to ride hard at high rpms but if I conquer the temp issue now I won't have any issues with added hp later. I have thought of adding an extra cooler in the rear right fender or one of the front ones. Just not sure which way to try.

Is there any chance you could ride your car at the higher rpms for about 10 miles (4000 rpm) and let me know what you reach? Do it a slow speed or any speed. I have trouble understanding why no other person has chimed in after doing this. I don't think 4000 will hurt anything even though it may be a bit loud... It will give me a starting point with what size radiator really works!

Cooling...
 

Yan,

Where I installed the 3rd radiator in my 966 won't be the same for your 911... I used the same mounting brackets as the factory "Tiptronic" oil cooler mount. I then connected the 3rd radiator in series with the two factory radiators.

Right now I have the car on my lift working out the new oil cooler so it's not going anywhere any time soon. I had 3 weeks of fun driving so I'll give it a rest while I do some more upgrades.

The only thing I can say is you can't have too much cooling capacity, why not change out the ring and pinion instead of the 5th gear. Then you have taller gearing through out the RPM range. If nothing else I would consider taller wheels...

I would also consider an oil cooler, my LS3 motor only holds 5 qts of oil and being in the rear of the car I don't think it's getting the same airflow as a front engine install. I know the same LS motor in the current 2014 Corvette is a dry sump engine. The point here is if you want a factory operating, everyday car I think you need to look at all of these options. If you just want a 0-60 hot rod then you don't need some of this.


http://forums.pelicanparts.com/uploa...1404399667.jpg

Mitch, what is the H x L x D of that center radiator? I wonder if I could run one in series with my rear one. No fan on it? No venting in back? Do you have the part number for it and the brackets? Would it fit on my 89?

The rack and pinion is a bit expensive right now. I have been restoring a 52 MB...

1952 220 Sedan W187 build restoration

So funds will have to wait and the one gear is not too bad.

Yan,

I can't find the dimensions right now of my 3rd radiator. I've got shop drawings and details but I just can't lay my hands on them right now. But I can tell you my radiator that I had custom built will "not" fit your car. It's not vented as my radiator system is a closed system. And I don't have a fan on the new 3rd radiator. So far it doesn't seem to need one. However once I get my oil temp uncontrol I'll revisit that.

Mitch, Just looking at my setup with my stock valence/spoiler - you are right - won't fit. I purchased this front spoiler from Better Bodies a while ago. I know that the cooler would fit with it but I really like the stock look. Thoughts? It would allow for the extra cooler. I also attached a CBR cooler from ebay that says:

CBR PERFORMANCE COOLING PRODUCTS SMALL OFF-ROAD OIL COOLER -10JIC W/ 9" SPAL FAN
8"X9.5"x2.25 Fans- Single 9" SPAL

If I could mount it somewhere it would be great as a second radiator mounted in series also. The rear right fender may work or near the rear bumper. or just the taller 5th gear...



http://forums.pelicanparts.com/uploa...1404435821.jpg

http://forums.pelicanparts.com/uploa...1404435837.jpg

Have you had any luck with your cooling.

Everything cools well except at the 4000 rpm range. I am going to add a front center 996/997 radiator and see if that is an immediate fix. Steve at renegades is always a help even with my toy jet setup. I am going to run some inch and a quarter lines up front and mount it temporarily, running it in series. If that solves the cooling then I will add the radiator into my spoiler or my 935 spoiler. This will tell me if I have or don't have enough square inches on my radiator... After that is solved I can add a tall gear also.

Not a single person did the 4000 rpm challenge! 😞

Yan,

The Porsche center oil radiator has 7/8" ports so other than your system holding more water you're still dealing with small ports. Plus the oil radiator has both ports on top, not one up, and one down.

Mitch,

I am going to see if I can get a custom made one with low restriction and 1 1/4 ports made. I just sent back a boxster front radiator with the 7/8ths ports. I am hoping that the small amount of sq inches extra should be the answer. If not then there is something else wrong. The car runs smooth and is a blast to drive. Long highway runs are the only issue at higher speeds...

Yan,

Sounds like you're on top of it... I just returned from a 4,000 mile in my 966/LS3?480 HP. I had no problems while driving in 100 degree temps and 75-80 MPH, but my oil temp got over 250 degrees. I'm not going to install an engine oil cooler, I hope that helps. If I drove 65 MPH the oil temp would go down. However at 80 MPH I'm only turning 2,375 RPM's.

Have you checked you oil temp?

Mitch, I really like your rpm range at 80. That is what I am looking for eventually. What is a good oil temp range? I will probably add an oil cooler eventually. Which one are you going to add?

Yan

Oil temp gauge...
 

Yan,

I'm installing an aircraft oil cooler with aircraft insulated hoses that will be custom made. I found this water and oil temp gauge on the internet. You can buy one or two probe sensors. The gauge can be set, it has an alarm that sounds when you reach your temp setting. Very small, has a big LED display...

Engine Temperature Alarm Dual Sensor Latest Technology Compact Display | eBay

Here's some pixs of my install: I did some surgery on the ashtray so it's hidden when not needed. This is the nicest compact unit I've found. The owner of the company is a car guy and we've become friends, albeit he's in Australia, I'm in Texas...

http://forums.pelicanparts.com/uploa...1405978759.jpg


http://forums.pelicanparts.com/uploa...1405978921.jpg

Oil Temps...
 

Yan,

You want your oil temp to be at least 220, but not over 250. If it gets hotter than 250 some of the additives can start to breakdown, at least that's what I've read. However for shorter time periods your synthetics can tolerate temps as high as 300 degrees. However you would want to change your oil after that.

I'm installing an aircraft oil cooler with custom made aircraft insulated hoses.

Mitch, why an aircraft oil cooler? Where are you installing it? Any photos?

thanks for the info! I will probably order the same duel sensor.

Yan

Yan,

I just completed the mounting brackets yesterday and will post pictures when it's done. I'm a pilot and most things with airplanes are well done, you're life depends on it. Plus the cooler fits, I had a hard time finding any place around the engine that would accommodate the cooler and still be in a wind stream, but not up against the exhaust headers. I didn't want to mount it under the front bumper valance since that would require a lot of plumbing. So I really don't know how well this is going to work until I give it a try.

You want to bring down the oil temp, but not over cool the oil. I wish there was a mechanical thermostat. I was told even if there was one that because of the sandwich adapter between the oil filter and block you can't cut off the oil flow, it you did it would stop the oil flow to the engine. I'm not sure this is correct???

I love this. Where in Hudson Valley are you? I'd love to see this car....

I did the 3500 rpm for a couple of miles the other afternoon. Temps never went over 200* and as soon as I went to a more reasonable rpm temp dropped to back to 191*. But again this is not in a Porsche. Front engine car

I can keep it to 195 or 200 but for some reason after about 5 miles the temps start to climb. I am sure that the oil is warming up good also. I never see a problem until about 5 miles and if you keep the rpms up it climbs. As soon as you drop the rpm's my temp drop immediately and go right back down to 190 ,180 and lower. If you never above that perhaps your radiator is just big enough. I ordered the front center 997 radiator and will put it in series when it arrives. I have a feeling that I will no longer get hot. We shall see...

Jbaker... New Paltz area

Took my front spoiler off and mocking up my Better Bodies Motor Sport 935 narrow body front spoiler. It has enough room for a 996/997 center radiator. I got one from Csfrace.com The inlet and outlets are 1.75" but with the Porsche plug and play hose it bottlenecks it down to 7/8"! I ordered a 1.75 to 1.25 silicone reducer and will run the front radiator in series... Got my fingers crossed.

Here is a photo of the mock up.http://forums.pelicanparts.com/uploa...1406595692.jpg

and hoping when it is all done it kind of looks like this...:

http://forums.pelicanparts.com/uploa...1406595742.jpg

Someone else is selling their 911 so I hope they don't mind I borrow a photo for inspiration...

creative floor jacks
 

Are you using USPS cardboard boxes as floor jacks? :) Very creative, but man that makes me nervous for you. It seems like they could slide to the side very easily. There are so few of us brave/crazy enough to put chevy's into a porsche, I would hate to loose one of us :(http://forums.pelicanparts.com/uploa...1406647578.jpg

it looks like the flat rate boxes are holding up the valance, not the car

Lol! You guys are killing me! Yes they are my floor jacks to hold up the valance so I guess you are both right! They were acting as shimmy's to line everything up.

http://forums.pelicanparts.com/uploa...1410399354.jpg

http://forums.pelicanparts.com/uploa...1410399422.jpg

http://forums.pelicanparts.com/uploa...1410399468.jpg

http://forums.pelicanparts.com/uploa...1410399503.jpg


Slowly getting there...

Leave him alone
 

People I can appreciate all the purists but its his car and he can burn it if he likes. If the LS conversion appeals to him then why post all those negative comments. We all try to do something out of the box to our cars to make them slightly different then the next guy. SO PLEASE! Stop all the negative comments, we are all here to appreciate Porsches and help one another. Just saying!

LS V8 Oil Cooler...
 

A pix of my oil cooler install...

http://forums.pelicanparts.com/uploa...1410793553.jpg

Mitch, we were looking at options today for an oil cooler. Same issues as you. Not much room. I may scrap the front radiator. Lots of plumbing unlike your 996 with porsche installed plumbing. I may just put the tall gear in first...

http://forums.pelicanparts.com/uploa...1410825985.jpg

G50 01 5th gear swap
 

I have the g50 01 tranny with stock gears. I am going to replace just 5th gear because anything more then that is really large bucks. The stock gear is in the .892 range and the tallest after market gear is around .667 Additionally, I understand that a G50 50 fifth gear will work and it is in the range of .756

My goal is to have a highway "overdrive" type gear for cruising and really drop the rpms. Can anyone give advise on what they have done for fifth including extra noise that an aftermarket gear makes and the large jump I would have from stock forth to the taller fifth.

If I do the swap is anyone interested in my 5th gear or trade for a tall 5th gear