Danno

"I have a question that I hope someone can answer. Everyone says that the stock NA drivetrain will not hold up against added power, yet at the same time people are chipping their 951's and doing other mods while leaving their tranny and torque tube stock. Why did Porsche engineer the 951's powertrain to handle extra power while keeping the na's powertrain at a bare minimum. "

Well, it comes down to how much MORE power & torque you're going to get when upgrading a 944NA vs. a 951. When you think about it, a stock 944 TurboS has a substantial 68% more HP and 84% more torque than a stock 944NA. That's a HUGE increase in torque. Even when you upgrade a TurboS with our GURU chip-kit for a +89hp/+139lb-ft increase over stock, that's only an increase of +36% in HP and +54% in TQ, only about 1/2 the difference between stock TurboS and a 944NA. So you can understand that to handle the extra power increase in going from a 944NA to a 944 Turbo, Porsche had to upgrade the tranny. AND also to account for the much higher upgrade potential of the 951... (more later).

also.... "Why did Porsche engineer the 951's powertrain to handle extra power while keeping the na's powertrain at a bare minimum. I'm not trying to start any trouble, I just want to know why Porsche would suddenly change their perspective on the upgrade potenial of their powertrains.""

It's not changing their perspective, it's a different perspective altogether. Probably because it's so much harder to extract much more power out of a 944NA, and even harder to squeeze out additional torque, that you'd be hard-pressed to upgrade a 944NA powerplant to the point where it will overwhelm the tranny. Certainly not for the $300 that it costs to get the additional +89hp/+139lb-ft out of a TurboS. Only dramatic changes like forced-induction or engine swaps will end up taxing the NA tranny. In which case, just take advantage of Porsche's R&D and use a 951 tranny. The TurboS tranny is even better becasue it has hardened 1st & 2nd gears.


Many people have put a 944NA into a 944 Turbo to get shorter gearing for autocrossing. However, that's a short-lived conversion that inevitably results in something that looks like this:

L8 APEKS

But how could you possibly know without doing it yourself?

I too am going to be doing this soon. I'll use a Camaro LT1 and an LT4 kit from Summit Racing. I will be buying a used motor, and I probably won't even tear it down before installing it.

I've hung with various "racing crowds" and I've known plenty of Camaro "racers." I've seen looooong, smoky burnouts. I've seen harsh drag race launches. I've seen as much as 150hp worth of nitrous jetted. I've seen missed shifts, redline bounces and the like. Still, I have yet to see one fail first hand, or require a teardown. This was all on cars that I knew well and had ridden in/driven many times.

As long as I'm willing to accept the unexpected, and I'm ready for anything...then why not? There is no downside. The upside is...if it DOES work, which it probably will, then I've saved a bundle of money. If it doesn't, then no harm done...I'll fix it and move on. I would have spent that money first had I gone the other route, without knowing if it was required or not. And I am one who dislikes throwing away perfectly good green!

I also think you're over-estimating the drivetrain/susp/chassis abuse. Hard launches will tend to break parts, yes. But dropping the hammer and passing at 80+ on the highway? Sorry, but it won't hurt anything at all with that much momentum already at work.

I am a little scared to get started as I'll be doing much of the swap myself (my biggest concern is the wiring...the mechanicals seem simple enough so I will put the motor in myself), but I'm excited for the finished result.

I'll be using the stock drivetrain as well...mainly for the reason that most of the talk about longetivity with said parts is heresay. I basically plan to start off driving the car easy, and gradually get rougher with it as I see fit until something breaks. There's been lots of speculation on this time frame to broken parts but I haven't heard it from the horse's mouth as of yet. Time will tell!

Canuck, where are you in the process as of now? I'd love to hear more about it. Drop me a line if you'd like. Best of luck!

Tom R.

canuck,
when you go from obd2 to obd1 how do you still need the key with the chip? a freind had a bitch of a time with his mustang when he put in a svt motor from a wreck. ford jerked him around until he could prove legitimate ownership of the motor.

it would suck to go through the whole conversion only to find out it doesnt start. my buddy was plenty pissed that he lost may and june to a silly issue.

Flying V

I originally used a Painless wiring harness, which came with a VATS module for the GM ECU. However, due to the lack of hookups for the transmission sensors and VSS (vehicle speed sensor), I decided to switch to the Accel DFI system. This solved many of my tuning issues (idle and deceleration) and made a substantial improvement in performance. In addition, since the DFI works off of manifold pressure (MAP) instead of air flow (MAF), modifications to the intakes and/or exhaust will be compensated for more accurately...

*Michael.*

Canuck,

Any update on the conversion?

-mike

L8 APEKS

Last I heard there was a snag, I e-mailed him about it. I decided to put it on hold because of my financial situation at the moment, and if I go ahead with a swap I'll do it to a base model car instead.

Bob Ward

Anybody talk to or know this guy??

I sent him an email off his website and it got bounced!

V-8 engine swap site

ilikemy944

Bob - that was on ebay I think... a long time ago.

dmsog

..if you want to shoot the **** about these conversions (or have any questions about them) I'm about 2/3 the way through mine. Here's a gigantic picture of the engine bay, before powder coating the headers and installing polished aluminum valve covers (NOT for 56k unless you have patience):

http://www.560sec.com/lt1.jpg

The first (next) hint of a flame about this topic in this thread and I clam up.

Doug

Matt H

I'll be using the stock drivetrain as well...mainly for the reason that most of the talk about longetivity with said parts is heresay.

You wont be using it for long, it is not heresay and the picture Danno posted is about right, I have 3 that look just like it.

FWIW, your quote is (I think) something I made mention of WAY at the beginning of this. For what he originally asked for I still think it is a mistake. He wasnt asking for more power he wanted daily reliability for which I woulc have 3 NA motors in the garage and one perfectly sorted in the car and have money left over. Additionally, somewhere he mentioned he got a ton of miles on his NA. Whatever, not of interest.

Doug, this was not a flame, FWIW, I am sure some people want to hear your experience.
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Bob Ward

VERY CLEAN LOOKING!!!

I wish my engine bay was so clean. You would have thought that avfter puling the motor so may times that I would wise up and doing some cleaning my self.

But i am focusing on getting a 3" downpipe to fit in the back of the engine.

Sledge hammer to the rescue!

L8 APEKS

Out of all of the V8 conversions running around now, I have not heard of, let alone seen, one of them that has actually destroyed the stock trans.

All of the naysayers are people who have never done the swap, and every person I've talked to with a V8 944 (and even two with stock 914 transmissions) are driving around with the stock gearbox.

Aren't there a number of 270+ to 325+whp 951's on the board? That's far more power than a stock LT1. Why aren't they blowing gearboxes left and right?

Anyway...if it's NOT heresay, then let me hear it from some of the V8 guys who have blown gearboxes with easy/moderate driving. (I don't know of any yet, though I'm sure there are a couple, naturally). Just because you swap in a V8 doesn't mean you automatically have to drive it like an F1 car. You don't need to floor it to reap the benefits of the swap.

I'm not saying the stock trans will be 100% a-ok to handle a V8 in a car that's driven hard. I'm simply trying to point out that if driven reasonably, there's no reason for the trans to just up and fail automatically because you have an LT1 under the hood, as many are making it sound.

EDIT: Dannos picture is also a picture referring to RACE CARS who use the N/A trans to RACE with because of shorter gears. Not the same thing at all. I doubt cruising down the interstate puts 1/10th the amount of strain on the car as a few laps of an AutoX course. It's not apples to apples.

Matt H

Aren't there a number of 270+ to 325+whp 951's on the board? That's far more power than a stock LT1. Why aren't they blowing gearboxes left and right?

BECAUSE THE NA AND THE 951 HAVE A DIFFERENT F*CKING TRANSAXLE.

I have had 3 NA gearboxes that look just like that, two were in a NA car (track abuse) one was lightly used in a 951.

I'm not saying the stock trans will be 100% a-ok to handle a V8 in a car that's driven hard. I'm simply trying to point out that if driven reasonably, there's no reason for the trans to just up and fail automatically because you have an LT1 under the hood, as many are making it sound.

YES, there is, it is called TORQUE. You are more than doubling (actually almost tripling) the stock output of torque.

Out of all of the V8 conversions running around now, I have not heard of, let alone seen, one of them that has actually destroyed the stock trans.

How many is that? I bet you can count them on two hands.

All of the naysayers are people who have never done the swap, and every person I've talked to with a V8 944 (and even two with stock 914 transmissions) are driving around with the stock gearbox.

The naysayers are myself, Danno, TonyG, and almost anyone else who has ANY experience with these cars at all.

Go to the turbo board and see how many of the modded cars have trashed turbo boxes which is an INFINTETLY stronger box to the NA box.
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L8 APEKS

Wow dude.

Decaf.

So then a guy spends 700 bucks and buys a 951 transaxle...are you happy now? Good.

Matt H

Yeah, probably worded too harsly. Oh, well. So goes life.
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