Chalt

I had a 02 VW New Beetle Turbo S (six speed manual), with 180 hp, and it felt very noticeably faster than my 86 stock 944 NA. The bug was top speed was limited at 135mph. So top speed was similar to the 944. But the bug's acceleration was noticeably much better. The bug was stock also, and the stock turbo was designed to kick in for low to mid-range throttle, vs a huge lag and a huge boost in high rpms -- the driveability was great.

So 147 hp to 180 hp is approximately a 22% increase, and it was objectively noticeable.

But it is also hard to compare the two since the bug was a turbo, so power delivery characteristics weren't the same as an NA 944. The 1986 951 has 217 hp. I wonder how the power delivery in stock trim would have felt compared to the 180hp Turbo S bug? I have never driven a 951, so I have no point of reference. Interestingly, I have a 2008 Civic EX-L sedan 1.8L (NA) that is 140 hp stock. The power delivery in low rpms is much friendlier to drive than the 86 944.

Jfrahm

To me it doesn't make a lot of sense to try to add power to car when they make a faster version you can just get instead. Particularly when there isn't a lot of power to be had, even for way more money than the cost of the faster version.
If the reason is sentimental, get over it. You'll be glad you did IMO. Modding a car reduces the value and what you'll get when you sell it to finance the S2 Turbo, 968 or whatever you decide to get. Best thing to do is keep it stock and only spend money on repair and resto and start saving/budgeting/searching for the replacement.

Tony5

Good question. Everything I've done to gain power has been during periods of downtime and with several things done at once. The only exception to this being the LR Maf+tune, where I had an opportunity to do a before and after drive very close together. It was very noticeable. If advertising is to be believed I maybe gained 10hp, which is a 7ish percent increase.
Adding a passenger is also very noticeable. The car weighs just over 2600lbs with me and some gas in it. If I add a 180lb passenger (another 7% change) it changes the cars attitude significantly.

V2Rocket

the actual number of HP gain is really irrelevant.
what matters is the feel of the thing.
the MAF conversion is transformational of the car - really amazing.
a header/exhaust may or may not make the car much faster - but the sound will change and it can feel more exciting.
a header does complement a big cam very well though, which is what a 944 engine desires most.

J1NX3D

I absolutely agree with this. There are gains in reliability and efficiency with some decent modifications that are worth the effort to upgrade from stock. With just an off-the-shelf reputable chip and a throttle cam the driveability and throttle response from my ROW (163hp) '86 944 was like a different car. This was about 14 yrs ago. I did a dyno before and after with the chip. The result was about a 2-3 hp peak. Was I disappointed? A little at first because you can get fixated on numbers on a sheet of paper, but it was so much more fun to drive and behaved like a more modern car because the hp/torque was improved overall across the whole rev range.

forwardtrends

Thanks everyone, I really appreciate all the insight.

Update: Mechanic called this morning and said that my stock down tubes were cracked and had been repaired a couple times already, the OEM muffler was shot with holes in it, and he suspects the OEM cat is probably on it's way out soon as well. So, I'm glad I installed the system.

He said it actually sounds good too (without me asking about that). Not too loud just more aggressive, and better throttle response.

Bad part is, he said the MSDS header is actually leaking from where it goes from 4 to 1. It has to come back off the car to get repaired.

I'll update next week with a video when I get it back.

forwardtrends

I got the car back with the full exhaust finally all welded and installed.

Haven't gotten a video yet ( wanted to get a drive by vid ) due to another issue I posted in the forum, but I wanted to follow up with my initial thoughts after driving it around a few times.

It's definitely louder but not too bad or ricey. Cold start is just a little grumbly and a little louder than stock. Sounds like it's definitely breathing better. Once it gets warmed up it has a nice tone to it at idle and just cruising, like another octave louder than stock if you're feathering the gas. When you hammer on it, it screams in a good way that I'm slowly learning to love.

It didn't add much to the initial launch (wasn't expecting much), but at mid to high RPMs it has a noticeable performance increase. Feels like it's got way more throttle response and a little more pull. I love stepping on the gas a lot more now.

I had to pay an extra $600 on top of the install costs, due to having to remove and weld the leaking MSDS header - which sucked. Also my old exhaust was way worse than I thought so I'm glad I replaced it. Down tubes were cracked and had been repaired a couple times, pipes were all rusty with holes in spots, muffler was splitting, etc.

I'll follow up again soon once I can get a start up and drive by vid.

forwardtrends

Here's a couple videos from today. One is cold starting it in the garage, and the other is once I had just pulled it outside. I'll get more rev and drive by videos once I get an extra set of hands over here.