Scott at Team Harco

Hey M -

What's the big idea coming around here and muddying the water with facts and logic? The man wanted to know if his 2.5 NA could turn the turbo...

theedge

No thats not the proper way to ask that...














The REAL question is can it turn TWO of those turbos.... And does he want to swap in an auto trans...

HAD to be mentioned

hrsteel

Pete944: 10k was a hypothetical redline for a full-on race motor, not a 300hp one. A 300hp 2.5L motor should be able to hit 8k or 9k. (Not withstanding design problems such as poor oiling) It probably won't like it and wouldn't be able to hold there, but it should survive a few over-revs.

Geo: Rough idling at or above 2k sounds just fine to me for a daily driver. (It's a far cry from the crappy Fords I always seem to end up driving.)

All:
- Cost: I am currently part of Georgia Tech's F-SAE racing team. As such I have access to lots of free facilities, materials, and engineering. I may be in a bit of a special situation, but self-engineered, hand-built parts are not nearly as hard to make as most people seem to think. We recently built a 33" Ti header for about $100 with some fun noodles, a TIG welder, and some salvaged tubing. (Gotta love e-bay!)

- Motivation: Something inside of me simply hates to see wasted potential. If my motor can breathe 50hp worth more air, I want it to. If I had a turbo, I would go through the same process, but I think the marginal cost to return isn't as good, and I would have a real grenade when I was done. Also, I kinda like my car, if 951 power cost me $3K and a rebuild every three years, so be it. I still wouldn’t be too far behind in the money game: I haven't seen too many turbos in good condition for $7K.

- Content: The lack of technical details makes me think that most of you are not super-geek gear-heads. I suppose that’s a good thing most of the time (and the reason I can’t seem to get a date even when driving a Porsche), but I was/am really hoping to get into the details of what a motor can and cannot do, and how they respond to particular modifications.

Danno

I can't believe no one's brought up the easiest power-adder of them all: NAWZzzzzzzzz....

snakepliskin

Hi,

Although I dont post much, this is definitely one of my favorite topics.

I am with you on making more power with an N/A...

I race an MGB with the SCCA in F-production (see avitar). It's 1800cc, nearly half the displacement of the 944. Its has a cast iron head and block, not to mention the head has siamese ports with the intake and exhaust on the same side. Gotta love British sportscars.

Anyway, I am putting down roughly double the little MG's factory HP, but the motor is an all out racer. Heres what it took for my application...Elgin full race cam, Full race head work, Cosworth Pistons, Carillo's, custom header and exhaust system, oversize carbs and matched intake, approx 14:1 compression and not to mention a fully digital MSD ignition system.

I believe that 944 N/A power is possible, but I would also say its a matter of sourcing the right go-fast parts and managing the strengths and weaknesses of the all-aluminum motor.

Best of luck to you,

Mike

Campeck

tottally off topic.

snake..was your name taken from the movie escape from LA?

snakepliskin

Ha.

Escape from NEW YORK!

-M

Legoland951

The 951 does not require a rebuild every 3 years. Try the search function on the highest mileage 951s I believe is around 350k miles on the original motor, trans, and turbo. My friend (drag racer buddy who builds 1500 hp+ Chevy BBs) and I looked into increasing the HP for the 944 n/a motor before. One of the first thing that needs to be changed is the truck sized hydraulic lifters. By design, these engines are not made for 10k rev limits or else they wouldn't put a lifter that is 3 times the weight of a chevy 350. Also, parts are prohibitively expensive as Danno listed. Unless your facility can fabricate a custom set of high compression pistons, a 16V head along with the saimese cylinder 3.0 block, you still have to put a decent amount of money to extract that little bit of power out of the motor. I gave up on the idea and bought a 400 hp n/a chevy 350 engine for my long term project in the 944.

hrsteel

14:1 ? That's getting rather high. How much advance can you throw at it and what kind of fuel are you on?

snakepliskin

hrsteel,

I run race fuel, 112 octane. Advance and retard are programmable and computer controlled, the MSD adjusts throughout the rpm range. Not sure off top of head where he curve starts, maybe 33-35 degs.

Oh yea, Campeck, "Snake Plisken" was also in Escape from LA, but the original's the best, its not shown much on tv. I think Escape from LA was just recently on FX or USA?

-M

hrsteel

Legoland951, Most 951 motors probably do not need to be rebuilt every 3 years. I was referring to a wound-out NA motor. At any rate, I doubt either motor could survive much longer than that under my control: I would likely have blown it up or have gathered enough cash to go through it again and make it meaner.

Geo

Indeed. And Jon Milledge Engineering has all the stuff someone would need. Now they just need to be doers instead of talkers and have to be willing to pay a reasonable price for the parts (The JME cam at $600 and header at $600 seem very reasonable to me). I cannot as I have class rules to deal with that won't let me. But people keep asking about this and no one has the stones to really take on a NA improvement program.

kennycoulter

i havent taken the head off of my 944 n/a or done much engine work, but about the hydraulic lifters: could they be replaced with "solid" lifters for lighter weight and higher revving? im only used to ford parts, but i know titanium valve seats and valves and keepers are available. and the new beehive springs, that allow higher revs because of less weight. seems like there wouldnt be much splurging really except on those and the pistons. what are the rods like in these cars? im pretty sure that SOME factory ford rods can be made to handle high rpm and power. i bet if the research is done, you can find a manufacturer that has a connecting rod close to the 944's size, that you could make a stroker engine out of. what are the pistons size? 4"? im sure its actually in metric... chevys i think are 3.5-3.75, and frods are 4" im sure you can get domestic similar pieces for tons cheaper out of jegs or summit, and have your school or whatever do some free machining. my 2 newest cars are the only forced induction cars ive really driven, and i agree i think i prefer the n/a predictable power. but im more used to torquey engines.

Danno

I would say that most of the extra costs in these cars when it comes to upgraded parts is due to the small market. There are easily 10,000x more Ford and Chevy engines out there, thus you can amortize development and production costs over a large number of them. In the Porsche 944 market, you gotta spread that same cost over a much lower number of upgrade buyers.

Yes, solid-lifters are availble, but they are expensive because you need extras, like precision tools to measure the clearance (can't check valve -clearance with cam-tower on the car). Then you'll also need a custom cam to take advantage of the types of profiles that you can use on solid-lifters (won't work on hydraulics).

Cams must also be matched to compression and you're cheating yourself if you stick with stock compression. Gotta go with at least 11.0:1, and if you're going to use race-gas, start at 13.0:1 compressoin. But the inefficient 2v heads won't really make the most of high-compression due to the slow burn.

Avoid titanium valve-seats, they're soft and do not conduct heat as well as the stock ones. You'll end up with fried valves. Beryllium seats are the way to go.

Rods are HEAVY. That's because of the super-heavy piston pins and pistons. If you lighten up the pistons and pins by 200gm, you can take another 200gm off the rods. Better to go with Ti rods anyway. Again, due to low volume, you're not gonna be able to find Ti rods for less than $2000/set. There are NO Ford or Chevy rods that will fit the 944 crank. You can try to retrofit a Ford or Chevy crank if you want, but you'll need to modify the block somehow to fit the non-metric main bearings. Again, a one-off job that requires spreading the R&D and production across a single car.

I'm not even gonna talk about pistons, it's been beaten to death on the 951 board. Bottom line is to use domestic non-iron-coated pistons, you gotta replace the cylinders. Sleeves are OK, but have had mixed success. Complete cylinder replacement with Darton MID ones are the only way, costs about $2000 per block, then you can use cheap pistons. As George said, it's easy to design an engine from your armchair, but no one ever steps up to the plate.

Geo

[QUOTE=Danno]I would say that most of the extra costs in these cars when it comes to upgraded parts is due to the small market. There are easily 10,000x more Ford and Chevy engines out there, thus you can amortize development and production costs over a large number of them. In the Porsche 944 market, you gotta spread that same cost over a much lower number of upgrade buyers.QUOTE]

Actually....

I'm pretty involved with the Nissan SR20DE market, as a consumer, an enthusiast, and a vendor. It's an even smaller aftermarket than the 944 in terms of production numbers. What is actually different is that the SE-R/NX2000/G20 guys actually are willing to spend some money to buy quality products.

In the Nissan SR20 world, cams run $600, same price as the Jon Milledge cams. I'm positive Jim Wolf Technology has sold more cams than JME. The latest header runs $600, same as the JME. I'm quite positive Hotshot has sold way more headers than JME.

Interestingly enough, the SR20DE market also suffers from a the same thing as the 944 market. Cheap turbo applications. But the SR20 guys still spend the $$$. The difference is some people willing to spend the money on quality products and proving their worth. It seems everyone in the 944 world just believes (incorrectly) that nothing can be done to improve upon the factory performance. If my car were a road car, I would do it, but unfortunately, I don't have the luxury of changing cams. I have a Bursch header, but once I get my car on the track and sorted I will either build a header to JME specs or buy one of theirs. I honestly think the first person to make and honest 200 hp with an NA (which I believe is very possible) will have plenty of business from NA folks who have brought their cars back to life, but don't want to trade a now pristine NA 944 for a fixer upper 951.

IMHO all it will take is someone buying quality components proven to work and turning them properly.