[covert420]

I am currently contimplating getting a Whipple SC and it made me wonder. Exactly how much boost can our engines handle before experiencing negative effects. Not just short term negative effects, but wear over time and other things of the like.

Also, what are some of the negative effects associated with too much boost?

The Whipple SC runs more boost then an M90 on a 4.0 pulley, and runs substantially cooler, so it is capable of achieving a ton more boost without overdriving things too much or creating too much heat. I dont know where the line should be drawn for 'too much' though.

(p.s. I have considered boring my engine out .02" as well, but am unsure as to what types of effects it would have when related to boost and engine heat)

 

[BumpinGTP]

im not sure about the long term affects, but i push 17lbs daily through my motor, non intercooled, on the stock bottom end, i know several other over 20lbs with the same setup

 

[2HiPsi]

With careful tuning the stock bottom end can take a lot of miles, boost, and high HP. However, our pistons are "glass" pistons and a simple tuning mistake can mean a big boom.

 

[covert420]

I plan to getting diamond coated forged pistons. This is what has me considering boring out my cylinders slightly. I dont know the effects of that either though :\

 

[1Hot97]

All things considered, boring the engine will reduce the compression ratio slightly.

 

[spd98]

You can't bore enough out of our motors to make a difference anyway. It's best just to do what you have to do to get everything machined perfectly. I wouldn't overbore unless the block needs it.

 

[Frankie]

i thought, from what I've read, that our m90's were "most efficiant" (sp?) at 9-10lbs. or did i imagine that?

 

[BoogieQ]

The point of 'usefull' boost seems to drop past 11 when heat takes over and you hit diminishing returns unless you run race fuel or get an IC

 

[FastGS88]

i run 14.5 lbs on a hope port M90 Gen3 with no knock on pump gas in 1st gear, and a few deg on pump gas at the top of 2nd, and thats mostly b/c my IDC there is 120%

yea, i think i need injectors and a fuel pump

 

[spd98]

The point of 'usefull' boost seems to drop past 11 when heat takes over and you hit diminishing returns unless you run race fuel or get an IC

Or run a genV. I know a certain someone is pushing crazy boost numbers (18psi on 1 run) with no IC and kickin ASS!!!!!!!!!!! I also have heard a rumor of people peaking a little over 20 with a genV.

 

[covert420]

well, I believe I am actually gonna purchase a whipple SC when I decide to upgrade my engine. So, the effeciency of boost levels on an M90 isnt really relavent here. I am wondering how much boost can our 3800 engines actually handle? With forged connecting rods and piston heads...

 

[BoogieQ]

I think you will find the power to be pretty sick around 15lbs but I do know many run csc's and other blowers over 20 and are having good success. I would however find a way to intercool it.

 

[Merc]

If my boost gauge is correct, i was pushing 17PSI out om my Gen 3 with a 3.0 pulley.

 

[covert420]

again, what kind of stresses does this put on your engine? What will wear and tear from high levels of boost? What are key parts that should be reinforced to prevent damage cause from high levels of boost (20+)?

 

[Merc]

Well if you are wanting to build an engine that will be a racing engine you will want all hardened race stuff, like pistons, cranks, rods, etc...


Pushing that much boost can easily make your engine go boom if you dont do it right. You can crack a piston or melt one. Blow the tranny. Throw a rod.

 

[covert420]

I plan on getting forged pistons and rods, S3 heads, an enhanced cam, stronger valvesprins, gaskets, bearings, bolts & studs, and valves. What else could high levels of boost effect?

 

[Merc]

You will want a good fuel system and certainly a scanning device.

 

[covert420]

ah, as in fuel rods and injectors? already planned. I am mainly talking about bottom end strengthening and known weaknesses when dealing with a boost of 20+

 

[spd98]

We haven't had any trouble using either stock or l32 rods (wich are somewhat better). Breaking rids is typically a result of a bearing failure as a result of oiling issues. I wouldn't worry so much about rods as the turbo car is running l32ers last I heard. As for the boost numbers thats not going to be an issue. There are people putting that down with a genV. The pistons will help because they are more resistant to kr and you WILL have kr at some point even if it's only in tuning.