Big boost turbo's

[GARRICK.CLARK1]

So,If you look on callook lounge there is a race team that's put a 1641 turbo motor down the strip with a time in the 8's. Big boost plays a part in this, Poss 36psi +, so 36psi, what sort of turbo is capable of this sort of PSI. Does the size matter or is it what its made from, special shafts/wheels etc.

[nbuscemi]

There's alot more to the equation than just boost pressure. The size / airflow of the turbo has to compliment the size / airflow of the engine you attach it to. To make matters more complicated, there are two sides to the turbo that has to compliment the two sides of the engine (intake and exhaust). There's no "magic turbo" that makes BIG power. Without the use of VCT, twin-scrolls, and things of the like, sacrifices in your power band have to be made. Big turbos yield big HP numbers (see Dyno-Queens) but are laggy and the power comes on late. Small turbos (most production turbo cars) hit hard, make lots of torque, and give that "in the seat of you pants" feel, but will fall on their face in high rpms.

Your best bet is you research Turbo-Graphing. This will explain the relationship between turbo air-flow and engine air-flow.

I know this doesn't answer your questions, and turbocharging is not as simple as bolt on and go, but research and learning is the key to making power (or deep pockets).

-Nick-

[GARRICK.CLARK1]

Ok thanks Nick.
I did research some before I bought the turbo I have now.
Mine is sized correct for the size of motor I'm using. Not much lag to be fare. I do feel I could go a bit larger and still have a street driver. I think I'll just get the local turbo shop to bore out the cold side INLET, put a bigger wheel on it to allow it to flow more CFM, Maybe bore out the cold side outlet to the carbs as that's on the small side. I don't want to make it a bad driver.
I'm currently using 2" tube from the turbo to the carb hats. I doubt there too small to flow well.
The one I have has 60 stamped on the cold side.
The cast aluminum turbo out pipe O.D is 2" but the I.D of it is maybe only 1 3/4"

[madmike]

Plus the fact that Ghia is tube chassis? wonder what his 'Power to weight ratio is?

[bug66]

Plus the fact that Ghia is tube chassis? wonder what his 'Power to weight ratio is?

It's not.. Pan car with ladder bars.

~500hp and ~850kg on the line

[bug66]

So,If you look on callook lounge there is a race team that's put a 1641 turbo motor down the strip with a time in the 8's. Big boost plays a part in this, Poss 36psi +, so 36psi, what sort of turbo is capable of this sort of PSI. Does the size matter or is it what its made from, special shafts/wheels etc.

2,59 bars (37,5 psi) on the 8,89 run.

It's a Precision 6262

[gbaker770]

That thing is badass. What kind of rpm is it making?

[Kalle]

I used a Precision 5862 AR58 on my 1641ccm and it really started to shine above 2 bar - 30 psi. At 1.8 bar - 26 psi my engine produced 360 hp at the wheels and I took it up to 2.4 bar (35 psi) occasionally. This is all about mapping, proper boost control and well made exhaust header. Reports say that our engines have a tendency to start lifting the heads at approx 43.5 psi but this will of course depend on a lot of things.

-K-

[Kalle]

That thing is badass. What kind of rpm is it making?

The log confirms that he stay above 5500 rpms over the whole run and shift at approx 8500 rpms. You need to be a little cruel to the mouse engines to make them shine. If you lift or shift like a grand dad you might as well abort the run because you will loose too much boost with the big turbos.

-K.-

[buguy]

Kalle I know you mentioned before that you drove yours on the street sometimes, would yours with the 5862 make any boost in the lower rpm range? My tiny turbo begins building around 2300 rpm, 5psi at 3000 rpm, and 10 psi at 4000 rpm. I'm just at the beginning stages of tuning, but since those aren't huge numbers either way, if a bigger better turbo would do similar numbers, I would consider upgrading. My car will be 99.9% street driven. I also saw, I believe, precision has a 5558 which should spool a bit quicker. But it's a gen 2 at close to a $2000 price tag. Owch!

[Kalle]

Kalle I know you mentioned before that you drove yours on the street sometimes, would yours with the 5862 make any boost in the lower rpm range?

Sometimes? I drove it on the street whenever I could and it was (and still is) road legal The turbo started spooling at around 3700 rpms and from 4000 and up you had to have at least one hand on your steering wheel and the other one on your hat That is the beauty of having a big turbo in combination with nice, loooooong turbo gear ratios. You can cruise all day long without creating any extra heat.

-K-

[buguy]

Gearbox is probably my biggest downfall at the moment. It's a stock 1965 1200 box. Super short first gear for sure.

[GARRICK.CLARK1]

Chaps. My next step up in power is
an intercooler and turbo upgrade.
My dilemma is modify the original turbo with bigger wheels etc OR
Get a bigger turbo. I don't mind some lag as its the 2nd gear on torque that I want.
Modify original turbo = same money as buying another turbo.
What is a common turbo being used.
currently have a 60 trim on a 1911cc with no major lag. so wanna go bigger for more AIR.
I don't need a carbon seal one, but it does need to be capable of big PSI. I don't want to be cringing while looking at 2 bar on the gauge haha.

[buguy]

Well Wally and Kalle both used Precision turbos. Maybe start there? I don't know you have checked them yet, but you are looking at $1100-$1800 for one of those. Maybe that will help your decision making?!

[Kalle]

Well Wally and Kalle both used Precision turbos. Maybe start there? I don't know you have checked them yet, but you are looking at $1100-$1800 for one of those. Maybe that will help your decision making?!

Correction; I do believe that Wally have never used a Precision turbo. They are usually way to big for him I used Precision and so does Niklas on his now 8 second super mouse engine.

-K-