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Pistons, cams, and a gt28

4K views 23 replies 8 participants last post by  20Tsaabsteve 
#1 ·
Got some extra money rolling in.
Thinking about getting a gt28 for the Saab.
Pistons, cams, clutch, and the LSD won't be hard.
But how in the hell do I fit a gt28 behind my motor? I know I need a new manifold. Does anyone make them?
 
#3 ·
because a gt28 is a much better turbo than a td04...

you do not need cams that is unnecessary, as for the turbo manifold just look at the cobalt ss's its the same manifold foot print you just probably want to pick up a log mani. theres several places like hahne, vulcan, ebay...ect you can search and find tons of manifolds.

Do keep in mind that if you do a custom turbo set up you will need to use an aftermarket bov, probably a external wastegate, and you will probably have to rig up a new intake pipe to the turbo, and not only that your gonna have to reflange your downpipe, plug your coolant lines, re do your oil lines (gt28 does not use banjos). and last but not least your going to have to set it up so your intercooler lines hook up. hooking up the turbo alone is not an easy job, but if you want an lsd and clutch your going to be doing a **** ton of work.
 
#4 ·
Yeah.. The 19t would be nice but it wouldn't make 350whp easily. I have a guy who can redo my current downpipe. And I know about the wastegate and Bov. Idk what I'm gonna do yet. My girl started talking me into getting wheels made. So who knows. Maybe I'll just do a 19t with pistons and get wheels.
 
#5 ·
19t wheel and e85 should get you into 350hp. I have been talking to john about it for a while. Those are actually my plans for my car. Doing the 19t upgrade and keeping a unleaded and e85 tune loaded on the handheld.
 
#6 ·
That's assuming he has access to e85.. It's not everywhere. As far as the piping I agree you would have to make a new intake and piping for the intercooler.. which would also have to be upgraded but that's all easy enough to do once you know the diameters you want and how you're going to route the piping it's as easy buying either a piping kit or piece by piece and mounting a new intercooler. What about injectors do you have them already? Jn2 and paco would probably know better than me but it seems that the common upgrade for the 93 are 60lb injectors but if you wanna make 350 reliably on premium pump you might want to upgrade the pump to. All of this is new to me though I'm used to the Asian market so I could be way off.

Paco, why do you think cams are such a bad idea? I'm just curious, if he's going to want to make a lot more than 300whp it might not be a bad idea. Do you know what the rule of thumb is on our valve-train is before upgrade should be pursued?
 
#8 ·
If your shooting for 300+ on pump your gonna need atleast 80 to 100 lb injectors. As for cams I don't think they are bad I never said that, but our cams are meant for boost I see no point in changing the timing when our cams have been shown to run just fine at 400hp. The other issue is what cams are you going to run and your going to need to get the tune in person I'm pretty sure.
 
#7 ·
GT28R turbochargers are internally gated from Garrett direct. No need in an aftermarket external wastegate. You can purchase an intake adapter if you get the compact version of the GT28R. The adapter turns the 2 bolt flange into a coupler fitting where you can just slip an intake pipe/coupler onto it and run it from there. Aftermarket BOV is suggested and I agree with that. The increase in CFM you'll want to vent off compressor surge as best as you can unless you want to recirc the surge into the intake which will keep spool up but you'll loose that whoosh/bov sound that most like to hear.

GT28Rs are water cooled and oil lubricated. He can retain those or at best build better lines that use new billet banjo fittings with braided lines (I would suggest this). New oil lines are A MUST and you have to use a restrictor inline on the feed line as BB turbos require less oil to run properly.

IC piping will most likely have to be adapted to suit fit. but if you are going to this extent to get things working how you want...thats just part of the game. Obviously you'll need a different downpipe fabbed or at best modify your current one if you have one with the 5 bolt garrett flange. You can buy a 5 bolt to a vband configureation from ATP Turbo and that will be a breeze for install/removal at any point. As for the exhaust manifold...I think there is a T3 to T25 conversion flange you can buy that will work but I'm not sure on total deck height of the unit to where it would still allow the turbo to fit under the hood with adequate clearance. You have a few things to look into but if done right..can prove very worth while.

I've nothing for on you drivetrain as Im not too famililar with the drivetrains on these vehicles but engine wise I can help out as best as I can. I build race engines for a living and use the GT28R turbos everyday on many of my builds. Its a great turbo to use and has a lot of response for the size turbocharger it is.
 
#10 ·
Um no if that were the case i could 300 to the wheels on stock injectors. Stock injectors are 36 lb goto a fuel to horse power calc you need around 60 to get past 300 to the wheels, but i personally would wana be on the safe side and run 80 (and if u were running e85 u would need 80s)
 
#11 ·
A stage III twinturbo Z32 (what I build -intake/exhaust/chip) puts down well over 300whp. Stock injectors are 370cc aka 35lb injectors. I dont see why he would need such huge injectors for the power he's after. 72lb injectors I use in builds making 7-800whp. My suggestion if he were to upgrade injectors would be around 450-500cc. That is MORE than enough fuel for that power.
 
#12 ·
That is a v6 it also has two more cylinders, two more injectors, and one liter of displacement compared to an inline 4. V6's require less fuel injection per cylender to make the same power. Just use a fuel injector calculator, also maptun, and nordic require 60+ lb injectors for their stage 4 and 5, also maptun requires 80 lb for the 400 hp gt28 build
 
#15 ·
Crank is a ****ty way to dyno tune a car anway I hate how all of the tuners for this car talk about bhp. Chasis tunning is a much better way to tune a car because you are putting the engine "under load." It's a bull**** selling point and the reason that car companies use it is to push sales.. 210bhp sounds a lot better than 178.5whp(no reference but average loss due to accessories and drive-train FWD car is generally agreed to be ~15%). Paco 630cc injectors are 60 lb injectors probably running close to 100% duty cycle so that gives me another reason to not like maptun because that's irresponsible tunning, you should never run 100% duty, in this case I agree with Paco. Check here if you don't believe me http://www.witchhunter.com/injectorcalc1.php4 If you want to make more than 350 WHP you would definately need more than 60lb injectors to be safe and price wise you wouldn't want to skimp the extra couple dollars to get 70lb(735cc) injectors.

As for the stock cams being "fine." You would upgrade the cams on a performance engine to give you the results you want. They make cams for the LSJ and they would work fine on this application. Tunning for cams isn't that difficult as it only requires the mechanic to know what your lift and duration is and he would adjust the timing accordingly to give you the desired results.
 
#16 ·
i agree with you about upgrading cam's, but besides the fact that i have no clue what the stock cam lobing is and the fact that the stock cams are boost designed cams i see no point. I can understand if you are defiantly mechanically inclined and you know where you want to be power wise and how you want your power band to be; that cams would be a good upgrade if you do it right. Im not playing cams out im just saying that there are no dyno results and no R&D put into any aftermarket cams available for the b207r and there has been no tuning results, and we have been shown that the stock cams can support 415hp 450nm with a 2871 and 60lb injectors.
 
#17 ·
I already have 60# injectors right now. I figured I would need 60# or bigger.
I ruled out the 19t already, it's a completely different turbo and I don't want to run max psi and risk blowing the turbo, I'd rather get a turbo that makes the same whp and run less boost on it.

I'm probably not gonna do cams, but the pistons are probably needed. Although the cobalt ss motor makes over 400whp on stock motor, and I haven't been able to find a difference yet except someone said they have an extra bolt on the flywheel.
 
#18 ·
you should never blow a good mitshu turbo, hell i boost mine to 26psi all day and its been doing that for atleast 40k miles. As for the turbo my suggestion is the gt28 or a precision turbo equivlant. as for pistons you can take a risk and not run them, but its about 500 dollars worth of insurance that you dont have to pay 2000 dollars for a whole new motor. My suggestion is weisco, wossner, je, mahle, and diamond piston in that order, and if you are looking lsj is the same but some of the company's do specific for the saab like weisco wossner and je but the list them as the same as the lsj.

just a side note another turbo to look at is the 20g, and if you look at the precision their cheaper journal bearing turbos are good and cheap, but their ball bearing's are amazing.
 
#21 ·
Okay, so I'm gonna snag some DR pistons.
Another question just popped up. I know the motor is an SS motor. what about the flywheel and everything after that.
Would an aftermarket SS clutch bolt right up?
cause i think it's dumb Spec wants 1k+ for it and they have it for like 600 for the cobalt without the flywheel.


and, currently I'm running the stock bpv. I have a block off plate, but when i tried to put it on, my ssqv wouldnt open unless it was under 15psi.
does the synchronic bov really work better? and how the heck does that work.
 
#22 ·
did you try adjusting the bov, im pretty sure if you adjust the screw on the back it will allow it to open sooner or later. my syncronic works great, the only issue i have is that it does open a bit delayed under low boost i think thats only because of electric bypass noid.
 
#23 ·
It's not that you need 80lbs, Paco can correct me but I think his point was it's safer to have some leeway in them. Like I stated above the math says that a 60lb injector is running at 100% at a tune that makes 402bhp on an I4. 100% is bad because injectors get dirty. So if your injector gets dirty and you start running lean you're gonna go boom and your friends are gonna be like dude what happened while you sit there palming your forehead. If they're affordable it's always wise to have an injector stay below 80" capacity. This will give you 20% to play with. Eventually you would need a new fuel pump as your power demands increase but so far seems like saab's is well enough. Good thing about a turbo application is that you can actually clean injectors by using high test gasoline.. but they'll still be dirty eventually.
 
#24 ·
Cams really wouldn't be a bad idea. The one downside is that you would have to have someone who knows these computers fly out and tune you. Or I found on here that there is a program to tune the T8's (trionic 8 suite) so if you found a tuner who can use it then you would be set. I have the factory cam specs if you would like to know what they are. I also have the factory LSJ cam specs if interested.

As far as pistons go, these are pricey but I would recommend them:
http://shop.zzperformance.com/store/p/642-Forged-Coated-Pistons-for-LSJ-LE5.aspx

For the turbo manifold, you can run zzp's:
http://shop.zzperformance.com/store/p/406-Ecotec-Stainless-Turbo-Manifold.aspx

It is cheap. And you can also use the bullseye s256 turbo they have in one of their kits for the LSJ as it bolts on to that manifold, so I would assume that if it clears the firewall in the cobalts, it should be fine in the saab. It also has a flange for your aftermarket wastegate, just hook up a dump pipe to the wastegate and done. You could also get the turbo kit they have for the LSJ's, although I am not sure if the charge piping would fit 100%.

As far as clutches go (don't quote me on this) but everything that I have researched shows the B207 block and the LSJ block to be the same. The heads are also the same, minus the cams. They also use the same crank. So I imagine that a clutch for a cobalt ss would bolt up (5-speeds, I am not sure on the 6-speeds). I am sure you could get a Cobalt flywheel just to be safe, that way you know it should bolt up.

Here is a very affordable clutch for the 5-speeds:
http://shop.zzperformance.com/store/p/489-ZZP-Stage-Clutches.aspx

I might check tomorrow or sometime this week to see what the differences are between the 5-speed and the 6-speed as far as clutches are concerned (I am a GM tech, so I can check the parts catalog and possibly check to see if there are spline differences).

Another thing that I will research in my spare time is the differences in the ECM's. If the Cobalt ECU would work in the Saab after rewiring then that would open up a ton of possibilities for Saab owners as you can tune with HPTuners, which is an extremely popular software. The hard part would be to make sure the Cobalt ECU would be able to communicate to the rest of the car.

Has anyone switched to a blow-thru MAF setup? (i.e. MAF in cold pipe) This could be done (would also need to be tuned) and could also open up an array of possibilities.

I will see where my research brings me. Sorry for the OT ;).
 
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