987.1 Mods so Far

Hello! Over the past couple of years I have filtered through several of the common areas for upgrades and modifications on the 987.1 3.4l. Many experienced members are providing great info, but if you are interested, here are some impressions and experiences with the mods I have taken on so far. Exhaust: Carnewal GT by Cantrell Motorsports. 4-stars! I’m not sure I have ever seen a bad review of this mod. At idle it sounds very tough, you will likely know your car is running in the driveway from inside your house. It is by no means subtle when you get on the throttle. Off-throttle cracks and pops are perfect. As a bonus, the exhaust came back from Cantrell cleaned and polished up nicely. One small tip, if you are a long way from Washington St., there are online shipping sources for discount UPS labels. I was able to cut UPS ground shipping costs by more than half using one of these services. Coilovers: Ohlins R&T, Tarett camber plates, and adjustable tie rods. Again 4-stars! The adjusting knob is easy to access from under the car without raising it. Just a few ‘clicks’ make noticeable changes to the feel. Also, height adjustment is easy and takes only a few minutes per wheel. One point I misunderstood in my research on lowering and coilovers; with the focus on gaining negative camber, the cost is you lose positive camber potential. That is, if stock you could adjust from +1.5 to -1.5, now you may be only to adjust from -2 to -5. On my install, the least amount of camber I could get in the rear was -2.5. I expected to set it up with a little less neg. camber in the rear than the front but ended up being able to get a max. of -2.2 in front and minimum of -2.5 in the rear. Adjustable control arms, I assume, would remedy this, but I’m not sure it’s a problem as the car feels great to me and handles like a little beast. Sprint Booster: 4-stars! I would sooner take out the turn signals than want to drive without this gadget. To boost longevity with the M97, I took advice from Flat 6 Innovations and LN Engineering. Installed the 2-qt deep sump & skid plate, BRS remote oil cooler, 160-degree thermostat, center radiator, new injectors, and O2 sensors. The oil cooler lines were a challenge to route without kinks or spots of potential abrasion. The shop ended up using some pre-formed lines with bends for some spots. Where minor kinks were left in the oil lines, small holes opened up within a few weeks (which turned into big holes) and those had to be replaced with some tougher hydraulic lines than what came with the kit. Still, the BRS cooler is significantly larger than the stock and I have to believe it makes a big difference. After the oil line leak, I installed an Autometer oil pressure gauge in place of the Sport Chrono stopwatch. If you don’t know, there is a port below the air box. There are good videos out there on how to install the gauge. I did have to use a 90-degree fitting for the sending unit to clear the air box. At this point I’m weighing what would be the best next step; sway bars, adjustable controls, headers & tune, or a limited slip differential. Or maybe nothing!

Bob, nice update and great pics. A couple thoughts on future mods. 1) Grilles to protect radiators. 2) GT3 brake master cylinder and stainless brake lines make the braking a much more enjoyable experience. They do to the braking what the Sprint Booster does to the throttle. 3) Tarret sways compliment the Ohlins very nicely. 4) Pedro’s brace for the rear suspension is an easy and inexpensive way to improve handling.

Thanks for the tips! I hadn't heard much about the brake cylinder upgrade. From what I've just been reading it sounds like a great next project.

I'll second on the grills. I'd go with Zunsport grill protectors for your oil coolers. also, -The GT3 brake ducts will fit the 987 perfectly. You can get them at suncoastparts.com -the all red euro taillights for the 987 look great on darker painted cars like yours -bumperplugs.com to plug those license plate holes in matching paint code color. -the strut tower brace from the 911 will fix a cayman as well. look up the how to on this forum.

Great mods and thanks for sharing info about them! Seems like a track weapon. FWIW - There's a lot of good grill/vent protector threads if you're interested. If you have more cash than time, the Zunsport is apparently fantastic. For my 981 side scoops, I wound up going with the $0.93 (plus tax) Home Depot special to catch the leaves and it surprisingly looks fantastic. (I originally ordered metal and that was a mistake...I scratched things up a bit and couldn't get it right.) Saved my vents a few times this fall already, with all the leaves that were caught (on just a few drives). Two questions for you, Bob: 1) Which model (manufacturer) sprint booster did you install? I keep hearing great things about it per changing the accelerator curve -- although it doesn't literally add horsepower.​ ​ 2) Which online shipping place worked for you for Carnewal? Shippo? I'm eventually thinking of doing Carnewal, but a round trip shipment from MA to WA is quite expensive.​ Cheers and enjoy the drive!

Hey there. The brand is Sprint Booster , I think it's the V3, specific for 987.1 . I believe it has 9 'street' settings and 9 'race' settings. I couldn't figure out a good place for the small controller. I have it now upside down next to the radio, which is okay. It really is amazing. Setting '5-race' is probably the best overall, but dial it up to '7' or '8' and the engine becomes ridiculously responsive. So much, it's easy to stall the car in 1st if I forget I've got it set so high. For the exhaust shipping, I used a site called 'Pirate Ship'. I know what you mean, UPS wanted $250 or more from Central Florida to Washington State. I left the UPS store thinking 'maybe I'll get the Soul Exhaust after all at that price!' I did a little googling and found that site. I think I ended up paying $99. I agree, I have seen the price of Zunsport grills. For that money, I'll add that GT3 master cylinder instead. There aren't too many leaves blowing around down here. Do you know if cars with the factory center radiator come with a grill over it?

Thanks for the tips! I'll be sure to look into the Pirate Ship thing. $99 each way sounds pretty reasonable, to be honest. Also cool about the Sprint Booster too.

Oiling upgrades. These will help with several M97 engine issues. Install a FVD 1/2 quart sump plate & windage tray. While you're in there switch out the oil return tubes that Porsche went cheap on. Upgrade those to the 996 swirl pots (Oil Separators 996.107.080.54) to help with removing foam from the oil before it's returned to the sump. Swirl pots spin the foam oil a circular cylinder to force bubbles out of the oil (left). Cayman tubes just sprays the oil against the side of the case (right). Switching to Driven DT40 5w40 or Liquid Moly Top Tec 4100 SAE 5W-40 & Cera Tec additive with molybdenum and reduce oil change intervals down to 5k or 6 months...

I'm with you and think I have those covered! 10 qts. of fresh DT40 in right now with a case of XP6 standing by for next weekend's Auto-X.

A few additions to your to do list; 1. Numeric shifter and cables. These two compliment each other and give you a real secure feeling of the shift engagements. I downshift a lot, so these parts grouping really help in the lower gears staying away from a dreaded money shift. 2. Tarett Cup Race LCA's without rubber bushings. 3. Tarett GT swaybars f and r. 4. 996 Cup front brake ducts and GT2 rear brake ducts. If using Tarett LCA's then a shop metal band to secure the duct to the bottom of the LCA. 5. Function First Orange engine motor mount insert and Orange transmission mounts. 6. Summer tires like RE71RS. 7, 1 inch wider wheels in front and rear. I have 2 sets of Forged light weight wheels, 18 X 9 in f and 18 X 10 in r. Titan 7 TS 5 and Signature Forged SV104. 8. Hartech sump distributed by Slakker Racing Developmennt which is a step above LN 2 Qt system in preventing oil starvation. 9. Soul long tube cat less headers with a Softronic tune . 10. Wavetrac LSD , no clutches to wear out and has plenty of torque transfer from spinning wheel to traction wheel without inducing understeer, Try these parts out, you will not be sorry, just a little less in your bank account. I've had these parts for at least 5 years without issue except for the Hartech sump which just became available in the US in the past few months.

But only as much as you upshift

Hi Bob, Nice mods so far. What exhaust tips did you pair with the Carnewal exhaust ? They look great.

That radiator is THE best mod you could ever buy for those motors… the rest is just great improvements, the radiator is a lifeline

Shameless plug , hartech sump install. Works great so far: https://www.planet-9.com/threads/diy-hartech-racing-deep-sump-install.255080 It's one of those mods that doesn't feel better, nor does it make the car faster, but it should keep the engine alive longer. Same with the radiator.

Maybe I missed it somewhere but what is your goal for this car? Street, track, show?

I like those too, they are the straight-cut black satin from Soul. I wish they were just an inch or so shorter so they would be more even with the plane of the bumper opening and not stick out quite so much.

When it comes down to it - a street car. I seriously doubt I’ll track it on a consistent basis, if ever. But, working on cars is a hobby of mine and figured if I can help the longevity of the motor and maybe up the suspension game a bit, that would be cool.

Bob, Have you installed sway bars? Your Ohlins give you plenty of ride height drop so you may need the Tarettt GT sway bars F and r and drop links from post #16 If you have not installed the GT3 front brake cooling ducts, I would highly recommend the 996 Cup front ducts as they are about 2X larger and catch much more cooling air. In the rear, GT2 ducts do the same thing as the Cayman does not have rear cooling ducts. If you are interested in a wider stanse and more camber, then I would add the Tarett Cup Race LCA's. I've had mine installed 5 years ago and have had absolutely no problems the these LCA's. Your car basically sits on these arms, and the Ohlins work extremely well with this LCA as well. Some people say, that these are RACE arms and will give you more NVH. Yes to a certain level, but they also give instant turn in response and control the camber nicely. In the rear, the axles can move forward and back a total of 3" with the OEM LCA's buttery rubber that connected the arms to the frame. Tarett's LCA's Cup Race description below. You will really like these mods. The red center solid thrust arm bushing is what I am talking about in both the front and rear axels moving forward and aft on OEM LCA's. "Solid thrust arm bushings and sealed monoball inner ends are used to eliminate the spongy rubber OEM bushings and provide a precision ride for improved feedback, steering response, and overall handling. Both are CNC machined from 6061-T6 aluminum alloy and are anodized red for a corrosion resistant and attractive finish. The solid thrust arm bushing is adjustable for increasing or decreasing wheelbase and adjustable caster. Camber and track width can be accurately and repeatedly adjusted with precision GT3 style shims. A competition proven design that allows for up to 20mm of adjustment per side and up to an additional 2 degrees of negative camber by adding optional shims."

Hey thanks for your reply, I've been wanting to ask you a couple questions for awhile now. First , I've read nothing but great reviews of the Tarett sway bars and LCAs, both from your postings and others. I think all those parts are in my various on-line 'Carts' all over the internet. Also, I did install the front GT ducts when I installed the Ohlins, just not the rears yet. I'm also hopeful I'll run across a nice set of wider used rims, but no luck yet. But...I'm thinking maybe I better replace the shift cables first. This car has 64K on it now. I keep thinking mine won't snap, that only happens to other people, but lately the shifting seems just slightly gummier, so its got me worried. I thought I would save a little with the OEMs, but they are significantly more expensive than the Numeric. So my question is - people always say the install is very challenging. What so hard about it, other than access and number of steps? Is there a difficult adjustment process once installed that doesn't get discussed as much as the physical installation? I suspect that is the issue, getting them set up right once installed. Did you have problems there? My other question is a little out there, but I have been curious. Have you ever heard of people or shops milling the heads down for more compression on these engines? My experience has been more with early GM cars and that was just hot rodding 101, a few thousands off the heads and a nice thin steel head gasket to up compression a little, gasket match the intake and exhaust runners and off you go. I haven't heard any talk of cylinder head work on these motors and assume there isn't much to gain. But I was just wondering if you knew if shops like Cantrell's were doing that sort of thing from time to time.

Bob, no milling of the heads to gain more compression, but here are shops that blueprint the heads by opening the passage way and smoothing the air flow to gain more air/fuel velocity on both the intake and exhaust side (porting and polishing). This is expensive as there are water and oil passageway that could be uncovered. The big boys just put in liners that are larger diameter and add higher compression pistons and lighter wt /stronger rods. Tarett GT sway bars and down links are almost a must have once you start lowering the car. One, the down links to keep the parts alignment correct and the swaybars with different holes in the ends to adjust the understeer/oversteer balance front to rear. Once you have this done, your shop can corner balance the suspension taking in drivers weight in the seat. This is done as usually only 1 person is in the race car. Factory setting is balanced is for 2. You can look up corner balance to see if you want the expense. The highlight is the turnin will be the same both direction as the diagional cross weight with be as close to 0 as possible. You will be surprised how flat the car will corner, almost no body roll. That puts more emphasis on street camber. So I would shot for about -2.7 f and -2.3 r. Having those Tarett LCA's allows for a wider stance, so you can have the outside tire side walls even with the side of the car.

I'm sold on the bars, links, and LCAs. Have to get through the Holidays and see how work settles in first of the year. I have one issue with these mods though, an it comes down to a sort of Newton’s third law problem; what I get caught dropping on Porsche parts comes back as an opposite reaction (although not always equal) for things like... new cookware, maybe a new sofa, new flooring! That is why someone I know thinks that Ohlins cost about $300 and I mail order special engine oil because of the savings; LN Engineering is like a new Amazon or Chewy, great deals!

Bob, It's part of the 5 year plan, or in my case 6 year plan. I had to make sure the other half got her say so. Hard to do with roll bars, bucket seats and instruments all over. She does not race so I have to respect that part. The NVH part is sort of ignored, as in I do not have much to say about her car selection. None of her girl friends have asked me to take them for a ride. Porsche vs book of the month club. Most of the husbands have ridden in the car though. I even let them drive it at parties, especially if they give a review with the Sprint Booster Red 5 engaged.

yeah, It's fun to build them over time and plan it out. Around here the Cayman is misunderstood. I have an old Chevy and friends and family love that car and don't understand why I would waste time with the Porsche . If they drove both, '66 Chevy vs. Cayman S , I have to believe they would see the light. I'd post a pic of that car, but not sure how that would go over on a Porsche forum... Anyway, again thanks for your input. I'm gonna replace those shift cables first of the year and then start planning for the other stuff in 2024.

I can relate, nobody understand the Cayman in my peer group as well. I'd love to see to 66 Chevy . I love all cars. I'll break the ice by showing my 68 Ford.

I hope you like the connectedness and immediacy of the brake pedal as much as I have. It makes the brake pedal almost as rewarding as the gas pedal.

@Bob E 396 I'm sure this is far from the most sophisticated method for flushing the ABS, but when I did mine a few years ago, I did it by driving the car. Basically, I activated the ABS about 10 times fairly extensively and followed that with a full brake flush (I had done a full flush before the ABS activation as well). Near my house was a single lane bridge with steel plates as the surface. Only about 40 feet long. I drove over it after a rain and hit the brakes hard enough to activate the ABS. I ran back and forth at least 10 times. By using a slick surface I was able to activate the ABS extensively, yet not put abusive levels of stress on the car. After doing the second flush, the pedal was very firm with very little travel. I don't know the Foxwell enough to point you in the right direction for an ABS flush. Perhaps someone on here does.

I was planning on trying that, lol! We have a little rain in the forecast for this weekend so why wouldn't that work! The Foxwell seems to get good reviews, but again I spent an hour more this morning trying to update it and actually got to a 'download update' window - which was dead and did nothing.

Nice

I installed a set of Top Gear catless headers and a Softronic tune to go with the Carnewal GT exhaust . I have about 100 miles on it since then. I have to say the car feels radically different and the attitude is significantly more aggressive. I would attribute most of this to the tune. The catless aspect is going to take some getting used to as I find the odor obnoxious. But the exhaust tone, especially at higher revs, is absolutely wild.

Buy a Sprint Booster and use Red 5 with soft soled shoes to feel the throttle pedal better. I have all above modifications and more. Using Softronic Race kit built especially for the 987.1 S. I know that I should be able to achieve the same effect by mashing the throttle, but no way. The SB simply is much faster, especially when used for down shifting. In traffic, you see an opening and just push on the throttle, the response is over the top. I use RE71RS as my street tire and have a Wavetrac LSD so no worries about wheel spin it just goes.