Campeck

and why is everyone stuck on suspention upgrades in proportion to the turbo!!! im not MAKING a 951.
im turbocharging a 944. the 951 is a different machine. im not copying ANYTHING off the 951 except the concept of the turbocharger. just because you have more power doesnt mean you need all the extra little crap porsche did. would be nice, but if you want upgraded suspension then BUY SOME!

Campeck

hell. a fuel controlling apexi afc2 only costs $200! where did you pull $500 from!?!?

hoffman912

sorry matt i wasnt comming accross as an *** hole. i was answering honestly. is this to be a test of ones self and their engineering skills. or are they trying to make a poor mans 951?

any time i see a 17 y/o talking about turboing an NA i assume they are trying to short cut the costs of the real thing. by being honest and saying its not cost effective, im not being an *** hole, im being realistic.

if its a project to make something cool, cost no object, then go for it, by all means, and do it right. engineering is cool stuff.

instead of spending 4 or 5k on upgrades to turbo an NA, i think it would be more effective to take that 5k, and tur the car into a more track worthy NA. better suspension, racing harness, tires, wheels, brakes, etc. extra power doesnt mean squat if you cant use it efficiently.

Matt O.

Hoffman you're the farthest from an ******* on Rennlist. It's just frustrating when a guy like Campeck is trying something new and all anyone has to say is negative. He's not spending their money -- Rennlisters can be so stupid sometimes.

like putting a 968 motor in my car was "smart." "Sell your car and buy a 968" right? Wrong. It was fun and I have a unique car. I think Campeck should go for it.

-Matt

Campeck

its alright...

im dead tired..not thinking straight. a coke then sleep.

Serge944

Campeck, take it easy. If i want to turbo my n/a ill consult Andy, because he is very knowledgeable. I'm sure everyone else would do the same. Btw, not everyone can get all that crap free from rennlisters...

Create a bullerproof transaxle would probably be better for you.

Matt O.

Oxymoron?

Campeck

LOL.
i dont know man...it helps me! *pffffft! opens coke and thinks..."hey! thats what the BOV will sound like when im finished!" and falls asleep.*

Porsche-O-Phile

For fuel costs you also have to consider the costs of the injector(s), wiring, harnesses, lines, etc. If you can do it cheaper, more power to you.

Look man, FWIW I think your project is cool. I'm doing a turbo conversion myself. All I'm saying is the notion of turbo-ing an n/a is never going to fly as a "kit" concept and be economically viable, unless some pretty drastic changes to the laws of supply and demand happen! Can you do it yourself? You bet. I'm doing it myself. I think it would be a great learning experience for you. Will you ever get back what you put into it? Well, economically no way - intangible "smiles per mile" benefits? Quite possibly

You may seriously want to consider upping the suspension on this though. If you want to do it later on after you've done the other stuff that's fine, but I think you'll quickly learn that power without control is nothing.

As my daddy taught me - "there's fast and there's half-fast (half-assed)". Get it? Take your time and do it right. You'll have more pride in the finished product.

KuHL 951

Sorry you don't agree but that extra ump comes with a stiff price tag to convert ...just replacing an N/A trans with a turbo trans sets you back some big bank. Parts are becoming harder to find as time goes on. The reason I said my N/A is the King of the Twisties is the balance between gearing and power band; it's just not the same with a turbo. You get a turbo on a 951 in the first place for the same money and even got some good brakes with the deal. Sorry you don't agree that's how opinions are...I've got both cars to drive and compare so I'll stick by that.

Geo

The single biggest hurdle, and one that should not be ghetto is the engine management. It is the key to this whole deal. An Apexi AFC2 is ghetto. I'm not dissing here. You guys know I think folks here should stop the narrow thinking that keeps development from happening. It's just that a good engine management solution is really necessary to do this right. Otherwise, I think turboing a NA 944 shouldn't be a big deal. I also think there is a market for it (as well as extra power remaining NA) because while 951s can be found for the price of a turbo kit, from what I can tell most are in need of a lot of restoration. A lot of people have restored their NA and don't wish to go through the process again with a 951. But I bet many would spend on PROVEN power upgrades or even a well designed turbo kit.

OK, just to stir the pot a little, here is what can be done with a proper development program. This car is a 2 liter twincam and is owned and developed by a good friend of mine. The car is a road car, although built heavily on the performance side (read harsh for a daily driver), although it didn't need to be. It's not a drag car. It has a semi-race suspension (no metal suspension bushings) and is pretty equivilent to a lot of dual purpose 951s. He just posted this to the SR20 Forum last night (Sentra SE-R, NX2000, G20). This car was built with pretty much off-the-shelf parts, just well selected and well tuned.

=============================================

Ok so we dynoed the latest set up at last. I know its been years since I posted but I havent had time to work much on street car stuff over the last few years since I started running in SE-R Cup.

Since I last talked about the car I added the following:

1. Turbonetics 60 trim TO4E in a .60 a/r compressor housing, 76 trim T350 turbine in a 0.83 turbine housing, single ball bearing center section. Housings and wheels ported and extrude honed polished.

2. O2 induction intake manifold.

3. 3" downpipe and Tial wastegate with sort of lame semi merged wastegate discharge.

4. JWT's latest 92 lb injector program with Lighting 80mm MAF.

5. Ported the F-Max/ Turbonetics exhaust manifold and gave it a light extrude honing.

The rest of the set up is very simple and not exotic either.

Off the shelf Turbonetics/F-Max turbo kit with slightly bigger than normal IC
87mm JWT Pistons 8.5:1 compression
Tomei Metal head gasket
Tomei Studs
Crower Rods
DPR light clean up headwork
Oil squirters
Underdrive pulleys
S3 cams
Crane Hi-Fire igntion

The power I am getting is crazy, beyond anyones expectations!

We put down 520 whp@ 7000 rpm and 450 lb/ft of torque @ 5500 rpm at only 20 psi of boost!

At only 15 psi it was over 410 whp!

This was with a super conservative program with a 11:1 A/F with JWT's off the shelf fuel and spark curves. With the reduced backpressure the engine would really respond to more advance and leaner mixture, not to mention more boost!

The clutch could not contain the power and this power was while the clutch was slipping. JWT is looking into ways to build a clutch that can contain this power and still be streetable! If the clutch haddent slipped, the power would have been greater!

So there is still plenty to be done.

We will develop a clutch, play with tuning and cams. I also plan to swtich to a Pro-Tech manifold soon as well. It looks like there will be a path to have an off the shelf parts, non exotic, easily duplicatable 600 whp formula for the SE-R soon!

========================================

That is what can be done. Very few 951s (like less than can be counted on one hand if that) have anything for this car.

Porsche-O-Phile

This is still a helluva lot more work than the word "kit" implies. You also have a HUGE problem in piston availability when it comes to alusil engine applications. The only options currently are the stock variants coming in various bore sizes or the Mahle Motorsports ones, which are ungodly expensive. Even with the latter, I believe your choices of compression ratios are very limited. 8.0:1 for turbo / forged construction or 9.5+:1 for n/a applications. That's a HUGE gap. I will likely just use 951 pistons in the Callaway project and slightly shave the head to bring up c/r by a tenth of a point or two.

Not to say it CAN'T be done with n/a internals but I'm a little leery of having a momentary tuning "burp" or lean spot that would be absorbed by a strong forged internals engine end up blowing up a cast piston and ruining the pistons, block, crank, etc. etc. etc. Essentially if that happens, the ENTIRE engine is junk and you're probably out a good several thousand bucks.

The alternative option is to run with steel sleeves and then you have many more piston options, but sleeving is hardly cheap and is not really part of a "kit". This is actually what Callaway did on their conversions (steel sleeves) and they opted to run 8.0:1 pistons of their own design and manufacture. At the point they were made, there were no 951s and therefore no other options for 8.0:1 pistons. Just a side note.

Also you have to consider the inherent problem of the n/a transmission. I personally believe it will hold up fine for a while under 200-250 h.p. applications ASSUMING it's not used for hard launches or anything. To go higher than that I'm absolutely going to get a 951 transmission - probably with LSD and actually transplant the n/a high gearing into it. This will give fabulous performance up to about 90-100 mph and nice tall high gears for highway / top end.

Geo

Jeff, very good points. However.....

I'm not buying the factory piston thing. I'll chalk that down to lack of research by those with 944s. Before you go off on me, it's a problem I face. My first race engine will be stock internals just for the sake of expedience, but I'm already thinking with the 101.0mm pistons for the NA being virtual unobtainium and even if you can find someone with a set they want your left nut and to hold a mortgage on a kidney. As I get closer I'm going to start talking with the various coaters, starting with Dan Swain of Swain Tech. The coatings on the OEM pistons are not magical fairy dust. Somebody can do this. I have no doubt of it. It's just a matter of finding someone willing to do a little work on it. I think Dan Swain can do it. They already make all their own coatings anyway so it's not like a lot of places that rely on coatings someone else makes.

In a nutshell, I think with some research and persistance, this can be overcome. Pistons still won't be as cheap as a Nissan or Honduh, but they won't require a Swiss bank account either.

The 9.5:1 CR of the NA is certainly an issue of concern. However, the Nissan SR20DE (NA) engine comes with the same CR and people turbo it every day. Of course, the combustion chamber design on that engine is much better and resists detonation quite well, but I do believe with a good engine management system and some good tuning it can be done. I have NO doubt someone like Danno could do it.

One thing I don't know about the stock pistons is whether some material can be removed to lower the CR safely.

I'd also agree about the production of a kit. It's certainly not something an individual would (or should) want to take on themselves. I think individuals can put one together for their own car, but trust me, there is a HUGE difference between producing a one-off for yourself and producing a product for sale. I found this out when I started my parts business (mostly for Nissans at this time, but I'm not a Rennlist sponsor so I can say more - we don't sell enough to sponsor anyone). A good kit can be done I think, but the R&D to produce a kit a monkey could install and tune (and you simply have to shoot for that level) is big.

Campeck

let me ask how most of you are so sure that a lean spot will blow the pistons? or a knock or two will blow a rod through the block?
if it hasn't been done with a stock na internals then all of those are assumptions.

geo. can you reccomend a good standalone or piggyback? ive been looking around (no im not using an apexi. it was an example) and have found a few. but im hesitant to try them.

Geo

They can't be 100% sure, but that is pretty much what happens. With boost you don't have to miscalculate much. Their warnings should be considered carefully. That said, folks have SC'd the stock internals 8v NA, so you should be able to turbo even easier. Don't expect to be able to use much boost though.

Sorry, but I can't recommend a piggyback. To me, those are ghetto and I doubt they will be accurate enough to do a good turbo conversion. As for a stand-alone, I'd really recommend finding one that can use a MAF, but most are expensive so most people use a MAP based system which IMHO are not a good a choice, but certainly less expensive and IMHO better than a piggyback.

Truth of the matter is, if I were to attempt this, I would buy the Apexi programmable ECU they sell (can't remember the name) for the Nissan SR20DET. Performance numbers for the engines are similar so the requirements likely be in the ballpark, and it uses a MAF and a knock-sensor. You'd have to acquire or make an engine wiring harness and do some modifications. Then you would have to reprogram. But, you'd end up with a reasonably modern ECU, sequential injection, MAF, and knock sensor. It would probably be cheaper and easier than buying a good quality stand-alone that will accomodate a MAF.