2.4T lack of power? or normal?
 

I recently registered my first 911 last week. I've been working on it for months to get it to this point. The car is a '74 coupe with a '73T motor that someone swapped in at some point. I am very pleased with how the car starts, idles, runs. Smooth & consistent. But the car has no get up & go! I can put the pedal to the floor & the car goes, but with no authority whatsoever. (My stock '92 VW GLi is quite a bit quicker) Is this what I should expect from this motor? Is it known for kinda being a dog? If thats the case, then I'll just live with it for now. The only engine items that I've looked at thus far, I installed Bursch headers & muffler, adjusted the valves & changed to NGK plugs. Plug gap is to spec & the points were replaced prior to my purchase. I also run a manual thermostat mod as suggested by Grady. As I mentioned, the thing runs very well, just no get-up & go. Open to suggestions: -John

Toast, it's only about 140hp, so I wouldn't expect the T engine to set your hair on fire. Does your engine have MFI, carbs or CIS? You might be able to tune it a bit for more performance.

Have you gone through check, measure, adjust? I was plesantly suprised by my 140 HP T motor, but then again I wasn't expecting much with a dead hole, it running VERY rich and TOTALLY worn out.

It has MFI. I'm combing the archives now to find more info on MFI & tuning. The PO did quite a bit of around town driving. When I was installing the headers, there was alot of carbon buildup on the exhaust ports. I carefully cleaned out what I could from there, but not sure how much that helped. (PO ran the car without the thermostat hose hooked up)
Since putting it on the road last week, I've put 700 miles on the car, mostly highway, mostly at 80mph :)

dead hole? I just found the CMA pdf article, so I will start some lite reading this evening. Hopefully a shady tree mechanic like myself with basic hand tools can handle this task.
-John

John,
Here are a couple of threads that you might find useful.

http://forums.pelicanparts.com/porsche-911-technical-forum/169445-mfi-thermostat-spacers.html

http://forums.pelicanparts.com/porsche-911-technical-forum/170242-mfi-tools-diyer.html

Lots of info in here, including good details on some specialized tools that you'll need to make or buy.

by the way, I have my 2.4 tuned pretty well (it still needs some tweaking) and its power is more than adequate for me. Kind of hard to describe how powerful an engine feels though.

I had a 1969 911T 2.0 litre car.

Although it wasn't fast for a Porsche, it was comparable to most 2.0 litre modern cars (which probably are much heavier).

It was faster than my 2.3 litre automatic SAAB.

Your GLI is around 134hp, and is probably heavier than the 911. So even at only 140 hp, your 911 should have a better power-to-weight ratio than the GLI (not to mention that it should have a lot more torque).

Your 911 if stock, would have been a significantly faster car than the GLI. Even with the smaller engine, it should still not be a slug. I suspect that your 2.4 is not set up/tuned correctly.

-MAS

True. My Gli has 170k on the clock & weighs 2528lbs with a 1/4 tank. (Use to track this car in its younger years).

Skimming the CMA article, it appears fairly technical & some tool fabrication required. I much prefer to do this myself & learn or at least work with someone with the nohow. Is there anyone local who has done this before who wants to tackle this with me?
-John
06776 or 12594

There is no way your GLi should be "quite a bit quicker" than a 2.4T 911. Something is definitely not right. I've owned GLi's and have driven a stock 2.2T and the 2.2T was quicker .....

I use to have a really well tuned low mileage 67K miles 1973.5 2.4 911T CIS.

It had a dansk sport muffler and MSD Ignition, aside from these it was a stock motor.

It was actually pretty quick, I easily took 3rd gear all the way up to 100MPH when I shifted it to 4th it would turn 110-120 MPH easily and still pulling.

My friend who use to race cars has a stock low mileage '85 GT Mustang and he said my porsche was much quicker.

He also went to a porsche school and studied under Jerry Woods and he works on my Porsche personally.

So a well tuned 2.4 CIS is not that slow. I heard a MFI is even a bit quicker.

Also bear in mind that the lower displacement engines do not come alive until about 3500-4000 rpm and then peak out at about 6000. If you are shifting at 4000 (like most first timers do), you are missing the best part in terms of power and sound.

My 2.4T has little power off the line. I consider 1st and 2nd gear are present just to get the car moving. Playing around in 3rd and 4th, while working the car's mid range is fun.

Toast, it's nice that you have MFI. :) With the info available here on Pelican and using the CMA procedure, you should be able to liven it up some more. MFI cars rock!

What kind of transmission does the car have, 901 or 915?

True. I am a bit hesitant to crank on it. I know my Gli is safe to 5800, I dont have that condfidence yet in the P-Car. I have done several spurts of taking it up to 5200ish on the 911, not much change in the power band.

Even though the car runs well, based on opinions thus far, I really should be getting more out of this motor. I will start digging & post results as it progresses.

p.s. I havent found the tranny code yet while crawling under the car. It is a 5 speed.



TIA, -John

If reverse is directly below 5th, it's a 915. Otherwise, 901.

You say it is running smoth; a sign of a health MFI.
Be sure to re-check your point gap(or dwell), then adjuct ignition timing. I like to adjust more advanced than spec, try up to 38 deg @6k, back off if detonation or a decrease in top end power. This will give more kick at the low end.
PS; Never take off that MFI system, nothing beats it.

I have a '73.5 T (CIS) and it certainly feels much better than any 140hp engine has a right to feel. Maybe it's the torque, maybe it's the car's low weight, but it sure likes to rev too.