How much can this take? - Second Generation Forum

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How much can this take?
Saturday, May 21, 2005 8:27 PM
How much power can the stock bottom end of a turbo sunbird take?
I've heard around 300, but I have big plans for it that is going to push it beyond that and I cant think of any way to make the bottom end stronger, except APR rod bolts.
So does anyone know for sure how much power it can handle? and What can I do to make it handle more?
Also what about the tranny? I've heard the same thing 300hp max...so what can I do to make it stronger, I'd also like to be able to do two wheel burn outs, lol is there anykind of LSD for the Getrag trans?
thanks in advance





Re: How much can this take?
Saturday, May 21, 2005 8:39 PM
what's up tyrin! miss ya buddy

as you may know, I'll soon be handling slightly over 400 but mine isn't a stock bird turbo. so really I guess I just felt like braggin'. lol. I think both the tranny and turbo could handle 350 most... I'm not entirely sure about the full specs on the stock turbo GM put on the bird any time I've ever heard someone bring it up it was 300 also.

wheel burnouts obviously means you need to find more ways to get the front to grip and stick low to the ground. I'm doing so much front end bracing. one thing I'm afraid of is when I get it on the strip, I know my front end is going to stand up. any way you can make the front end more aerodynamic is also a given. that way the car is pushed closer to the ground by the air, causing more grip. I'm about to burn out the tires on my stock rims til I get everything set.

so as usual, I was of no help at all but I missed ya and felt like braggin'. still have those tails? if not that's my own fault I've been MIA lately.



Originality and Creativity surpasses Popularity

Re: How much can this take?
Sunday, May 22, 2005 8:27 AM
I've still been around, just havent posted much latley cause after youve ben here for over a year you'll notice how boring all the same topics get as there posted over and over again and new things dont pop up to often.
Anyways, I have huge plans for this and I worked it all out and I'll be making anywere from 350-465 I found some pretty cool formulas online to calcutate aproximate horsepower I dont care how much the stock turbo can take cause I'm not using it I've got a little surprise, I found a turbo that is putting 4 cyl into the 8's in the 1/4 mile. I dont plan to run 8's thats just insane, I'm shooting for 12's and maybe 11's depending on how hard it is to get into 12's.
I've got lots of ways to gain traction, the biggest things are slicks, and a two stage boost controller, with the two stage controller I can limit boost just low enough so I cant spin the tires on launch and then once I'm up to whatever psi its set at I can flick a switch and it switches me back to high boost, I bassically have two grainger valves and a vacume switch that directs air through one or the other, dawes devices sells them, but I just made one its not hard.
I've also told you about my copper head gasket so I can crank up the boost, and I've got a few secrets for getting quite a few more psi in there, I am going to be running 28psi which might sound a bit insane but if you knew the ways of how I was packing it in there its safe, the only thing i'm afriad of is breaking something in the bottom end, I've made the top almost bullet proof and I'm not worried about the pistons cause there forged, its just the crank and rods I'm worried about.
Anyway's I caould go on forever about this, lol so I think now would be a good time to end it before it gets any longer.




Re: How much can this take?
Sunday, May 22, 2005 11:16 AM
When you reach the 200hp/ liter mark, you're really in a whole new world. Sh^t breaks. Not just cranks, or axles, but all sorts of things. The car gets hammered and unexpected failures occur, like alternator brackets cracking, or motor mounts failing every couple of weeks, or splits appearing where body seams are welded together. It's really a whole different experience. Tuning and driveability can be a be-atch. Injectors large enough to support that much hp don't like to be "turned down" to allow frivolous things like idling and driving to/ from work.

The engine build is really critical at this level and throwing something together with stock parts and/ or clearances can easily result in that same something being thrown back apart. 28 psi boost is definitely in the "not fooling around" region... you'd better understand how detonation occurs, how fueling and temp and octane and cylinder head design work together to prevent or encourage it. No engine is immune to detonation, and when you do things like installing forged pistons and super-strong head gaskets, all you're doing is changing what's going to fail if there's a problem.

I would, if I were you, start learning a *lot* about tuning and especially with the factory ecm. You can buy a 3 bar MAP sensor and use a custom Syclone/ Typhoon program with it in the stock turbo 'bird ecm to have good factory style engine management. I would try not to rely on FMUs and MAP / wastegate bleed valves.

Remember that it's torque, not hp, that breaks things. 300 hp at 1000 rpm will do serious damage while 300 hp at 5000 rpm isn't so bad. The low rpm power figure comes with a tanker-towing 1576 lbs.ft of torque while the higher power figure is produced from only 315 ft/lbs tq. 315 ft/lbs applied to parts that are already moving is much more likely to be non-damaging. One advantage to the turbo imo lies in it's ability to produce a wide torque curve, which in turn produces quickly rising hp numbers. I would try not to build a peaky engine which sacrifices the wide torque curve for a higher power output in a narrow rpm range.

Before using your "magic grip" traction aids, remember that every system has a weak link. When you increase power and improve traction, you move the weak link to some other point. I often think it's better to design in the weak link on purpose... then you know what's going to break first. If you picked an axle, for example, you could carry spares to the track and change them right in the parking lot. If you don't know what's going to break you just might end up towing your car home.

hth
-->Slow
Re: How much can this take?
Sunday, May 22, 2005 4:51 PM
Very well said slow. every point I agree on. especially...

slowolej wrote:Remember that it's torque, not hp, that breaks things


that's why I've been spending so much time reneforcing and bracing the front end. knowing what I have braced and where and knowing what my weak points are. all because while I'm going to be pushing just over 400hp, that's not what concerns me at all. as you said in the quote it's the torque that called upon my attention first and that's where I started the work.

tyrin, I've got a few things up my sleeve as well. I've been hit with little things here and there and a few tricks and toys added in during the process as well... that's why I'm not finished yet. it's taking a bit longer than I had expected.



Originality and Creativity surpasses Popularity

Re: How much can this take?
Sunday, May 22, 2005 7:01 PM
i've read there rated for 300ish with the ARP bolts...




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