The Saab Link Forums

The Saab Link Forums (
-   N/A Performance Modifications for the NG900 / Old 9-3 (
-   -   Ever tried to Turbo a N/A? (

Saabotage89 08-22-2007 09:12 AM

Ever tried to Turbo a N/A?
Has anyone with a 2.3L 900 S N/A ever tried to put a turbo on their car? I know everyone will tell me to just go buy an SE, but I'm curious if this has ever been attempted.

I'm sure there's talk of it somewhere on here... maybe someone could direct me to the right thread?

Thanks :mrgreen:

stevehayes01 08-22-2007 09:25 AM

Try starting here...

Now with that said you will probably find little support for this idea from most people here (with the exception of myself and a handful of others). IF you want to use the standard Trionic to control the car then I beleive it will be much more complicated to do.

If you look at most Honda or Acura motors that are boosted you see 9.2.1 as an average compression ratio on them. So how far off is the compression of the 2.3N/A motor from that?

Just off the cuff I was thinking for the parts needed I think you could source a 2.0 Crank and rods and then add some dished pistons and a megasquirt system and go from there.

stevehayes01 08-22-2007 09:47 AM

When I built my N/A turbo saturn I used a copper gasket from a company like this company to lower the compression ratio on my car.

JK 08-22-2007 09:52 AM

My opinion on this is that the standard high(er) compression 2.3 in the n/a ng900 would probably be fine to throw a few psi of boost at.

If I were to get a n/a ng900 the route I would go would be to source the following:

exhaust manifold - off of any turbo ng900 or og9-3
Plumbing from a 2000-2002 9-3 (or any 9-3 with the T7/Viggen style intercooler)
ETS/Forge intercooler
TD04hl 15t turbo and associated plumbing (oil feed/return & coolant feed and return) - no need for a bigger turbo with the stock 2.3i internals
exhaust - 3" downpipe with stock exhaust/saabsport would be fine, 3" turbo to tailpipe might be better.

Lastly you would want to find someone who can rewrite the Motronic ECU to keep your fueling (A/F) in the safe range.

Other things to think about are ignition control and boost control, and possibly the need for upgraded injectors and knock sensing/protection. You could use megasquirt to get the whole fuel, ignition, and timing thing taken care of if you were so inclined.

This is a project that I would really like to see someone do, it should produce a pretty peppy car, and really wouldn't take a ton of work to get it going (getting it all tuned may take some time).

edit: And yes, I have turbo'd a n/a car before. I did a 1983 900, I left the high compression motor in, and it was probably more difficult to turbocharge that car than it would be to do a ng900 because of the scarcity of parts for those old 8 valve classic 900s. I've only driven the car about a mile since I did it, so it's been more of a boredom/side project

Saabotage89 08-22-2007 09:54 AM

Well what about the viggen turbo set up? I know the N/A has the b234 and the viggen has the b235, but they're both 2.3L...

I guess I dont really know much about viggens (someone please enlighten me!).

I'm just looking to get more power out of my 900 S without having to sell it, haha. The car is kind of a family heirloom, and i like having a project to work on, and I thought a turbo might be fun / a nice challenge :D

Any other sources of power gain other than air intake and exhaust for the N/A?

Drew in Houston 08-22-2007 09:55 AM

Steve's right. It would be neat to see you do it, but your problem is going to be compression ratio.

I seem to remember reading somewhere that the NA's are over 10:1 so unless you lower the compression you won't be able to run pump gas. You could probably build a high compression turbo setup that would really scream if you had access to high octane race gas all the time.

Perhaps running water/meth injection would let you boost enough to make it worthwhile?

The other issue would be the engine control and since your combination would be very different than what's out there already probably your best bet would be to go with a stand alone controller.

90SPG 08-22-2007 09:59 AM

If you go through all the trouble of turbocharging your n/a, which I fully support, you might as well put on a c900 exhaust manifold so it sounds like a car it supposed to sound.

Drew in Houston 08-22-2007 10:03 AM

Is the bore the same as a 205R motor? I wonder what you'd get if you transplanted the 205R pistons/rods/crank into the NA? Of course at that point you'd probably be better off just swapping the whole engine.

Saabotage89 08-22-2007 10:04 AM

Yeah... stevehayes01's link above said the N/A's were at 10.5:1

Sounds like quite the operation... problem is that this car is also my daily driver, and unless i plan on not going any where for a while... this probably wont happen anytime soon :(

... anyone have a loaner car? haha

Saabotage89 08-22-2007 10:06 AM

really glad to see some support on this though... i was almost afraid to post because i thought all id get would be "Get a Turbo!" or "Buy an SE!"

:D thanks guys

Drew in Houston 08-22-2007 10:08 AM

If it were me and I didn't want to change cars, I'd run the one that I had till it dies and in the meantime keep a lookout for a wrecked B205/235R that got hit in the rear, and buy that car outright for the engine swap and all the supporting pieces, harness, turbo, etc...

The other issue is how many miles are on the existing engine? You probably wouldn't want to just bolt a turbo onto a tired high miles engine anyway.

stevehayes01 08-22-2007 10:10 AM

For the occassional use you can put your car on the "bottle" with a 50 Shot setup that will run with no real issues.

But if you are going to go forced induction then I really have to say lower the compression ratio first and then look at boost.

Now you could talk to JE Pistons or one of the other manufacturers and tell them what you want to do and they should be able to build a piston for you (on special order) that would accomidate some of the compression ratio issues.

Or do the always mentioned..... 2.0 Crank, Piston and Rod swap which essentially give you a 2.0 motor (in rough translation) with a little extra bore.

stevehayes01 08-22-2007 10:14 AM

90 mm bore, 90 mm stroke, 10.5 compression ratio on the B234i

Where I think the B205R has a 90MM Bore but a 78MM stroke if I remember correctly.

Drew in Houston 08-22-2007 10:15 AM

The other issue is how many miles are on your current engine? If the car's a '94 with a bunch of miles it may soon be time to consider a rebuild/upgrade anyway?

I don't think you'd want to put a real high miles daily driver on the bottle, or add a turbo for that matter.

Although... a high compression turbo engine with full time water/meth injection might be doable, and would be very cool too.

stevehayes01 08-22-2007 10:17 AM

All I would say on a higher mileage car and using the bottle would be to do a HG on it and make sure that there is no blow by going on with a leak down test on the cylinders.

AS for a spare car keep an eye out for a low cost C900 of 9000 and use that as a daily while you build a turbo 2.3(used to be n/a) sleeper!!!

Saabotage89 08-22-2007 10:19 AM

think i could find some ricer out there running the same compression and run a similar turbo set up? probably not, eh? theres just too much coming into play with boost now a days ;)...

just seems so easy for all those damn japan cars to slap a turbo on... ta da!

its not fair!

haha :)

Saabotage89 08-22-2007 10:21 AM

oh... my car is pushing it for sure. i shouldnt even be thinking about this stuff with 150,000 miles :D

curiosity killed the cat right?

stevehayes01 08-22-2007 10:26 AM

You know if it the compression ratio was under 10:1 (say anything around 9:5:1) I would say to go for it in stock form with and use an SDS controller to add fuel to the motor when under boost.

I just think that with an almost 10:5 compression ratio you will end up grenading at some point and time. But man keep in mind.... dont be afraid to dream!! Thats how this country was built!

JK 08-22-2007 10:39 AM

I've heard of people running 12+ psi on b212 motors in classic 900s. Not sure of the compression ratio, but it's up there too.

Tweek's Turbos 08-22-2007 10:44 AM

First off, take a look at your mustang, now look at how fast it is/ compared to the money you spent on it.

Now look at the na saab. Think about the money that will be involved in making it slower and more expensive than a regular turbo saab. Do you want to be in so deep, as with the mustang?

Yes the Na 2.3 and viggen have the same displacement, but the viggen is made for the rigors of turbocharged life, the 2.3 na wasn't. Thats why we put 2.3 9000 aero engines in our cars, not 2.3 na engines.

All times are GMT -8. The time now is 01:05 PM.

Powered by vBulletin® Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Friendly URLs by vBSEO 3.5.2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
All content is copyright The Saab Link and it's original authors.

Garage Plus vBulletin Plugins by Drive Thru Online, Inc.