How would stock Buick turbo do on LS1 at 5-9 psi?

[Brainhead]

I got a used GT6776 for a 99 Corvette and I'll be running methanol with the turbo remote mounted near the rear axle, but I was recently informed that this turbo might not like this low boost level.
I'm not concerned much with choking power off over about 5k RPM's, I'm willing to trade that for power down as close to idle as possible up to 4500. I had planned on buying a stock Buick turbo too and seeing how it does, but I would appreciate thoughts. And I'm all about doing things on a budget.

 

[Getsidewayz04]

why dont you just mount that 6776 under the hood? there's really no such thing as turbo kits on a budget, if your gonna go the turbo route I would just spend the money and do it right the first time. just my .02

 

[turbo buicks]

I got a used GT6776 for a 99 Corvette and I'll be running methanol with the turbo remote mounted near the rear axle, but I was recently informed that this turbo might not like this low boost level.
I'm not concerned much with choking power off over about 5k RPM's, I'm willing to trade that for power down as close to idle as possible up to 4500. I had planned on buying a stock Buick turbo too and seeing how it does, but I would appreciate thoughts. And I'm all about doing things on a budget.

run the 67. a stock buick turbo would be out of air so fast on an LS1. seriously ur dealin with basically 2 more liters of displacement. go get a compressor map of both turbos and plot out your engine airflow specs and youll see what i mean.

 

[turbo buicks]

Turbocharger Compressor Calculations


theres another website out there where u input the specs and it automatically plots the specs on the map, ill try to find it.

 

[Brainhead]

Thanks.
I can't mount it in the front because the manifolds on the Vette come out so close to the cross member. I think it is possible to put a turbo on for relatively cheap. I'm on my way to doing it. (Of course if I were paid $5 dollars for every hour I've put into thinking about it and working on it, it would end up costing almost as much as a kit I could order. But this way I will have done it myself and learned a lot.)
My method in the past with go fast things for cars is to buy the parts that sound reasonable from what other people have said, put them on, and learn as I do it, and learn more after it's done. You can spend a thousand hours researching something without ever getting anything done.

 

[Blazer406]

Here is a T66 compressor map. I don't have a 67 compressor map... but this is the closeest thing I have (the GT style compressor wheel is slightly different and this turbo has a P-trim 76 exhaust wheel I think)

The T66 wheel isn't real happy down that far on boost. It seems to be happy from a pressure ratio of 1.6 - 3.4 (approx 8 psi on the low end to 35 psi )

I think it will make a ton of power on the street.... maybe not ideal.... but bad @ss none the less.....

 

[turbo buicks]

lookin at that map, even at 1.6 PR and 30 lb/min air its still 74% efficient which is good. i think 1 lb/min = roughly 10 hp

 

[turbo buicks]

Thanks.
I can't mount it in the front because the manifolds on the Vette come out so close to the cross member. I think it is possible to put a turbo on for relatively cheap. I'm on my way to doing it. (Of course if I were paid $5 dollars for every hour I've put into thinking about it and working on it, it would end up costing almost as much as a kit I could order. But this way I will have done it myself and learned a lot.)
My method in the past with go fast things for cars is to buy the parts that sound reasonable from what other people have said, put them on, and learn as I do it, and learn more after it's done. You can spend a thousand hours researching something without ever getting anything done.

research isnt a waste of time and can save u money in the long run. remember what they say, "measure twice, cut once"

 

[ITSNOTAGN]

2 stock buick turbos would still choke off that engine. put the one you have on, even in a rear mount situation it will spool good enough. honestly for a LS1, a T-70 is considered the minimum for a front mount setup, and a 67 is a great rear mount turbo. you should get boost by around 2800 easily with that, and you can say all you want that your fine killing power over 5k, but i wouldnt beleive you for a second if you told me that. it is a very very dissapointing feeling when your turbos out of breath at 4k, i know.
Gary

 

[Blazer406]

I found a site that had a chart of engines... and their respective flow rates at different RPM's....

LS1 Engine Flow Rate

It says that 9 psi (1.61 Pressure Ratio) in an LS1 @ 5000 RPM flows 47 lb/min of air..... now looking at the map I posted above... it is about on the 70% efficiency on the lower portion of the map....at lower rpms (3500) the flow drops back to 33 lb/min still at 9 psi.... this is better on the compressor map for efficiency...about 74-75%.

Should be around 510 fwhp maybe....educated guess

 

[JOELO'S T-TYPE]

I saw an install like the one that he wants to do on "Horsepower" on Spike TV about 3 weeks ago. I see what I can find, that Vette sounded NASTYY!!

 

[Brainhead]

I'll have to study all these flow rates and efficiencies one day. Right now I'm content to trust you who know and just concentrate on buying and installingl.
I know what you mean about high end power ITSNOTAGN. I consider sometimes that I should set my rev limiter to 6100 to save the engine, even though it can be safely spun to 6700. But in a tight street race I'd be willing to drive it to 7200 if it would go that high. At those times I have no concern about it blowing up, I'm just thinking about winning.
But still, I would rather have power down low than up high because I hardly ever get a chance to race anyway.