The "4.9 liter turbocharger, stage 1" thread. - Page 11

illumina · #**151** (**permalink**) 09-19-05, 02:36 AM

Quote:

Originally Posted by N0DIH

Here are the details on the pistons:
http://kb-silvolite.com/spistons.php...tails&S_id=624 for the N*
and
http://kb-silvolite.com/spistons.php...tails&S_id=228 for the 4.5L/4.9L

Interesting, they are 1mm difference in size, and nearly identical everything else. So it would appear they are a decent swap. Comp height is the same, and pin is the same (0.0002 off)

Those links don't seem to work...

N0DIH · #**152** (**permalink**) 09-19-05, 09:23 PM

Go to KB-Silvolite.com and go to Piston Search by Manf and go Cadillac. Look for 4.5L/4.9L and go to the N* one.

Also: http://impalassforum.com/noncgi/ulti...c;f=7;t=016829

For a turbo for sale....

CallMeCrazy · #**153** (**permalink**) 09-23-05, 11:30 PM

Just so you guys know, I haven't forgotten about this thread, but I have been busy. I just completed my first baseline runs on the dyno with my new motor and pulled 233 hp and 343 fpt on a 12V SOHC FWD motor

Since I last wrote in this thread I have also taken on the job of turbo repair at a local shop. Any rebuilds I do are all done using a Heins TC3 balancer and all bearings and seals are brand new. I can warranty every turbo that goes out the door for a full year.

http://www.turbomasters.net

As far as your project, I have some other links I can provide as far as knock control and engine management, unfortunately my dinner break at work is over.

I'll try to post some more this weekend and get you some info.

As far as widebands, check into a PLX made by PLX Devices or a a ZT2 made by Zeitronix. Both of which are top quality items and pretty much the best value for the dollar that you can get for A/F ratio analysis.

I'm still working on the compressor map and the links that you provided will help a great deal, I just have to find time to sit down and crunch numbers. I have a coupel additional info files that will help me figure out various pressure ratios acrossed the board. I should be able to find a guesstimate compressor map for choke and surge as well as a guesstimate efficiency table.

EDIT: Check this unit out for knock control rather than an overly expensive MSD BTM which retards timing based on boost when it's already too late:
http://www.jandssafeguard.com/

CallMeCrazy · #**154** (**permalink**) 09-25-05, 04:11 AM

I'm also going to resize the Pr chart that I found (earlier in this thread) for the RHB series which shows RHC6 and look at the difference between RHF found on IHI:

I have to find out how similar RHC6 and RHF6 are, my guess is that they are the same internally, only the RHF6 is newer.

Here is the RHB/RHC Pr chart:

Capt Fiero · #**155** (**permalink**) 09-26-05, 11:55 AM

Mmmm, Boooost. After seeing PBJ running around in his 4.9 Turbo made some impressive 1/4 runs with a stock 4.9 and boost that as soon as I get all tweaks done to my motor I may look into running 10psi on my 4.9 in my Fiero. (93 Eldorado motor)

davesdeville · #**156** (**permalink**) 09-26-05, 01:41 PM

Quote:

Originally Posted by N0DIH

Calculate the boosted airflow requirements. If the turbo is at 14.7 psi, you are double the CID. Make sure the TBI unit will flow enough air for you, at 7.5 psi you are ballpark 450 cid. You may need a 454 unit, stock maybe, maybe a little porting. You don't want it to be a boost restriction and having it backing up the intake tract. I need to look at the allante intake more (is that Stage 1 or 2?). Make sure there is some plenum under the TBI. Being the 4.9L isn't a high revver, the 454 TBI is probably sufficient, for stage 1....

You aren't going to need a bigger throttle body since the air is compressed it will fit through a 4.5 TB just fine. No way you'd need a 454 TB.

Capt Fiero · #**157** (**permalink**) 09-30-05, 03:01 AM

Quote:

Originally Posted by davesdeville

You aren't going to need a bigger throttle body since the air is compressed it will fit through a 4.5 TB just fine. No way you'd need a 454 TB.

Uhm, do me a favor, pick up a drinking straw and blow through it, pretend that you are making 5psi of pressure from your mouth through the straw. (your mouth is the turbo) Ok now pinch the straw a bit, you are still making 5psi out of your mouth but the amount of air getting out is not the same amount.

You want Zero restrictions between the compressor housing and the combustion chamber. Having too small of a throttle body is like putting a restricter plate. The turbo may be making 10psi of boost in the area between the compressor and the throttle plate, but if it can't flow that much air even compressed through the TB then it wont be getting full boost to the intake manifold.

Hence why even turbo imports install larger throttle bodies and larger down pipes.

More air you can get in and out the more power you make.

And if you can do it with less restrictions you can make more power with the same amount of initial boost.

I don't mean to sound harsh, but I have really been thinking about tossing a turbo at my 4.9 Fiero. So I have been doing research on the subject. Just to help with the higher end department. Right now it drops out around 130-140mph I would like it to be able to pull strong to 150-160mph. (without using nitrous)

P.S. if you want a bit of a laugh, take a read at Capt's Beginner Turbo Site

I wrote this for the absolute novice person looking to do a Turbo 2.8 V6 Fiero. The language used is plain English and simple terms instead of technical specs. So it is not meant as a bible just a basic get to know your turbos.

davesdeville · #**158** (**permalink**) 09-30-05, 06:51 AM

The throttle body is going to be just as restrictive naturally aspirated as it would be turbocharged. Do you gain power when you swap a bigger TB on a NA motor? If so then you'll gain more under boost. If the intake manifold is more restrictive than the TB then it won't do you much good.

Capt Fiero · #**159** (**permalink**) 09-30-05, 01:56 PM

Yep the factory TB is a restriction. That is why swapping to the Allante intake is worth 20hp on it.

Think of air like water and boost is like thicker air, and the thicker air is even more sensitive to restriction.

illumina · #**160** (**permalink**) 09-30-05, 04:26 PM

Quote:

Originally Posted by Capt Fiero

Yep the factory TB is a restriction. That is why swapping to the Allante intake is worth 20hp on it.

Think of air like water and boost is like thicker air, and the thicker air is even more sensitive to restriction.

The Allante intake plenum (uper intake) will also help to cool the charge air because of the large size from what I understand...

And yes, the factory TB is more of a restriction when running more boost. I would think that for stage 1 and 4-6 psi it will be ok, but not for more. That's why I am going to order an Allante intake manifold (upper and lower) to cure any issues there with stage 2.

Dave, when running a higher amount of boost, air is being forced into the TB unit and beyond. A smaller unit may restrict the air charge, thus limiting the amount that will be fed into the engine in the useable RPM range and may also damage intake components...

For example, when force-feeding 10 pounds of boost in the under 5000 RPM range, you want all of that 10 psi to be used with nothing left over in the intake tract. This will not only help make power where it needs to be, but it will also keep parts from flying from an over-boosted intake setup. Larger is better indeed!

davesdeville · #**161** (**permalink**) 10-01-05, 06:01 PM

I'd have figured the allante intake makes more peak power because of the long runners. But maybe I'm used to northstars where a bigger TB is worth like 3hp and costs hundreds... Like I said, the throttle body is going to be just about as restrictive naturally aspirated as it would be turbocharged (percentage wise.) If a bigger TB would get you 2hp n/a, it would get you about 4hp on a boosted motor making 400hp (from boost alone.) Think of it this way, right now your engine is under 14.7 or so psi boost, so air is still getting forced in through the intake system, boosting a car isn't much different from running it at a higher atmospheric pressure like below sea level.

illumina · #**162** (**permalink**) 10-01-05, 06:21 PM

Quote:

Originally Posted by davesdeville

I'd have figured the allante intake makes more peak power because of the long runners. But maybe I'm used to northstars where a bigger TB is worth like 3hp and costs hundreds... Like I said, the throttle body is going to be just about as restrictive naturally aspirated as it would be turbocharged (percentage wise.) If a bigger TB would get you 2hp n/a, it would get you about 4hp on a boosted motor making 400hp (from boost alone.) Think of it this way, right now your engine is under 14.7 or so psi boost, so air is still getting forced in through the intake system, boosting a car isn't much different from running it at a higher atmospheric pressure like below sea level.

Tom (N0DIH) has been really helpful as well as Capt_Fiero. I trust their opinions because they've done turbochargers before. Me and Tom talk continuously outside of this thread in regards to this project...I also appreciate your input, but at this time, we pretty much know what I must use to make things happen.

Dave, I didn't make this thread to argue with anyone, and I am not going to argue with you about it either. Please refrain from arguing with anyone on this thread, as I DO NOT want this thread closed too.

Thank you

illumina · #**163** (**permalink**) 10-01-05, 11:57 PM

I have been writing Terry Kelly about the Cadillac ECM. Although he will not give out the definition files for the Cadillac ECM (because it's not really that complete), he might know a couple of people that may be able to burn a chip that will supply enough fuel for stage 1. Rockcrawl from Fieroaddiction.com is one of them, in which I have emailed just a few minutes ago. Terry said he would email me about another person that could help out too.

Capt_Fiero has also been very helpful in this too (you know what you did!!! Thanks dude

)...

So here's the big thing, should I make successful contact with someone who can make this chip happen, I will need to either have CallMeCrazy finish his compressor map, or I will have to build one of my own, just to see where boost will likely occur with the 4.9 liter engine so that fueling this thing wn't be the big issue that it is now. Either way, this development is potentially huge, so let's hope this works out...

N0DIH · #**164** (**permalink**) 10-03-05, 01:35 AM

The reason I chose the 454 TBI unit, is it is dirt cheap at a boneyard. I am a big proponent of GM factory parts, often found at boneyards. My 301 Turbo ran a 800 CFM Q-Jet (I haven't seen smaller than 800 cfm after 1976 or so, they are easy to ID), draw through, carb size was never an issue, and that is wet flow. But when I had the secondaries locked out for something like a misadjusted choke, I was limited to 85 mph at WOT. And the risk to my carb'd turbo was lean mixture, which is a piston melter.

Agreed, it might not be a major HP gain ("Buy now for an instant 100 hp gain!!!") but to keep things flowing proper with minimal issues, go as large as a N/A motor is for the boosted engine (a 300 CID boosted to 7.5 PSI is approx 450 CID airflow). Strictly by the numbers. If I knew fluid dynamics and all, I might be able to tell you exactly what the stock Cadillac 4.9L throttle body will flow. Else, it is a simple one to bolt on and eliminate issues.

Yes, I know, at sea level, 14.7 pressure is already present. Which gives us 300 CID. So we will be higher than that at any boost level over 14.7.

So a turboengine at 6 psi boost is likely the same in power as a N/A engine with an atmospheric pressure of 20.7, right?

Quote:

Originally Posted by davesdeville

I'd have figured the allante intake makes more peak power because of the long runners. But maybe I'm used to northstars where a bigger TB is worth like 3hp and costs hundreds... Like I said, the throttle body is going to be just about as restrictive naturally aspirated as it would be turbocharged (percentage wise.) If a bigger TB would get you 2hp n/a, it would get you about 4hp on a boosted motor making 400hp (from boost alone.) Think of it this way, right now your engine is under 14.7 or so psi boost, so air is still getting forced in through the intake system, boosting a car isn't much different from running it at a higher atmospheric pressure like below sea level.

illumina · #**165** (**permalink**) 10-03-05, 02:30 AM

Much to my chagrin, there will be no hacking of the Cadillac ECM. Rockcrawl has pretty much set me strait on this issue from an email today.

That said, there are currently four options that I am will to try:

a.) Megasquirt (MS) fuel system. I would use this system to run two TBI injectors in reference to boost. There will basically be an extra fuel pump, feed line, and return line feeding the TBI system for auxiliary fuel supply. Because the MS system reads over 2 bars, fuel wouldn't come on until boost is being made if I so choose...

b.) 454 TBI setup. Tom, I would like to know exactly how to power the injectors and what parts I need to make this work. Please let me know because I cannot find the information you gave me a while back...

For both of the above systems, I will have to adapt the throttle position sensor from the current 4.9 liter setup to work with the TBI setup. It's all a matter of tuning then.

c.) Another ECM that will read boost. This will be especially difficult because of the Cadillac BCM will not be able to function without the stock ECM...

d.) MSD fuel management unit. This device gives extra voltage to the fuel pump, which in turn overdrives the injectors. Along with higher flow injectors and a rising-rate fuel pressure regulator, this is an option. The thing about this setup is the lack of tuning that can be done...

Please feel free to give any extra options if there are any...