Jekyll & Hyde

I have done searches and a lot of reading, but I am still left with a couple questions.

I am looking at this bbsdesigns kit. I am going to have everything ceramic coated too. I live in texas and I am concerned about the under hood and combustion temps.

1) One, I have a set of Aluminum L98 heads that I was just about to send off for porting and building. This kit doesn't come with an intercooler, and I was wondering which one would be the best for ported plenum, runners, TPIS maifold.

2) I am still not sure about the cam selection...what is the best cam for a setup like this. It will be used on the street mostly and is going to be a daily driver, so I would just like one to build some power for now until I decide on a new engine.

3) When is the MAF going to be a restriction for turbos? 5lbs, 9lbs? Procharger doesn't say anything about it being a restriction, and they are using 9lbs. I also mean for tuning, at what bar/psi should I be looking at using the sy/ty ecm?

4) Would a 3" exhaust be large enough for both downpipes to fill, or is it going to have too much backpressure for a system like this? I only have about 2 1/4" of clearence for the stock exhaust since I lowered my car, so I don't think that true duals would work well.

5) Last one, how do you read this correctly?



Sorry for the many questions

Jekyll & Hyde

ttt - hello?

BBSDesigns

Hi Maroon-IROC-Z,

To keep the temperature under control when using turbochargers or headers is always good to use some insulation device, such as wrapping material, heat shields etc..
If you are going to purchase another kind of induction I suggets to get the Holley Stealth Ram; more bang for the buck with this option, quick access to injectors, simple designs and good air flow specially on high rpm's.
If you are going to keep it for daily driving I suggest to keep the stock cam it would work just fine.
The MAF won't be a problem, I have pushed slightly over 30 punds of boost a couple of times with MAF and no breakage or restriction problems have occur, but is always better if you can get rid of the MAF.
My 87' GTA had 3" dia exhaust pipe with a free flowing 3 1/2" custom muffler on the back, I managed to get 573hp with this exhaust. If you get the kit just tell the muffler shop technician to join both exhaust pipes that come from the downpipes in a "Y" configuration and then route them in a single 3" dia. pipe to the back of the car. You can get one "Y" from Summit for the muffler shop work installation, I've seen their(Summit's) "Y" connectos and they are very good made.
The graphic shown is the compressor map chart.
The horizontal values is the flow you are looking for. Lets say that you are looking for a turbo that flows 60lbs/min or 30lbs/min using two turbos for your forced induction engine project at 5500 rpm's. The vertical values are the pressure ratio or boost that you are going to run the turbo. The pressure ratio is the result from the sum of atmospheric pressure 14.3 plus the boost or psi you want, lets say 10 pounds of boost. That gives you 24.3 which is then divided by 14.3 = and gives you a pressure ratio of 1.69. Now that you have the boost that you want to run your turbo(s) and the flow needed for your engine, you go to the chart to see if that turbo(s) is capable of supplying the flow that you will need. For that particular compressor wheel the turbo will supply the flow you are looking for at about 122,000 rpms and in the 60% efficiency range which is still accepted. Below 60% is then better to get a bigger compressor wheel with more flow. In twin turbo applications the flow of the engine is divided by two. Remember that I just took some numbers randomly just to explain. You will need to know the theorical N/A flow of your engine makes at a given rpm and then calculate how much more flow the engine will make at a given boost. Then with that final value and planned boost you start playing as I just explained above. I really hope that you understood it. If you need more info or a more deep understanding I recomend getting the "Turbochargers" book by Hugh MacLnnes, is very good

Jekyll & Hyde

This is great information. Sounds pretty much that everything that I have now will work (except have the y-pipe made) for now, until I want more boost. This engine won't take much more than 7-9psi, but with intercooler, I could bring the boost up, and later my other engine...I could boost almost max on the T3(60").

Thank you.