Twin turbo V8 systems, can you beat on them???

[shortrack]

If I were you and had a clean slate I would do a LS with a Magnussen type blower.

Hey thanks for chiming in Charlie.....do you have a car with that set up?....I know you have the ex Tony Stewart Nascar.....how do you like the engine in that?.......is it race gas because Ive sworn myself to building a pump gas engine.

[shmoov69]

Well it has definately been beat on!! Prolly no less than 50 passes down the strip......among "other" activities not on the strip!! Lol

The carb mods are basic stuff at first. Which were cutting the choke horn off and welding up the rod holes and putting solid floats in it. Whammo, that's it!! LoL! After that while trying other stuff was adjustable air bleeds and drilling out the PVCR (I think that's what it was called) channels out.
The boost reference part is on the fuel pressure regulator only. Gotta have a return style fuel system also.

[MonzaRacer]

OK so are there any turbo guys(JIMMY?) who can tell me if this turbo is any good spec wise
http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWAX%3AIT
I have been told by guys using it its reliable but I just dont completely understand reading turbo info.
So I am wondering if I do something like Jimmy's but use an LT1 intake and my ci will be in the 302-305 range if these would actually work or are they some odd ball POS?

[DButler]

I have a pretty much stock 355 with a mild cam in a 67 camaro. I am running twin 57mm turbos with a front mount intercooler. I am running custom built stainless steel headers. My fuel system consists of a BG 400 pump with an Aeromotive boost referenced regulator. I had my carb modded by the carb shop in Cali, and it seems to be fine. I have got to drive it much yet, but what I have driven it, it runs cool and makes awesome power. We still have to fine tune it and dyno it. I am using an Innovate LM2 for air/fuel ratios. I have pictures on my PT garage.

[Ash]

Ahhh...the E-bay turbo question. Can't speak from experience, but many others have. Just Google E-bay turbo and spend some time reading all the forums that pop up...there are PLENTY. Jimmy brought up a good point with the balancing, but you have to consider that a good balance wont make up for crap internals or questionable quality control over the long haul.

[aronhk_md]

avoid the ebay turbo specials...as mentioned its not worth it when something goes wrong. For a couple of dollars more you can get quality stuff. That said there ARE good deals on ebay for turbo piping and connectors.

A single turbo adds complexity to your powerplant...twin turbos add more. The argument for twins has always been a quicker spool up, but a properly sized single can really spool just as quickly, and a larger single is actually more EFFICIENT. Not to mention less expense up front than twins. Twin Turbo sounds cool when you say it though.

As for whether they can stand up to track abuse...watch the following video. I think these guys are in Holland? I know that at least in europe they were a bit of a sensation. Anyway, their 1407 hp twin turbo knightrider style trans am has a few entries on youtube. Its fun to watch the smoke billowing from the tires as it accelerates after turns...lol.

http://www.youtube.com/watch?v=5S4KY5_nO_o

In fact, I believe the car was run at an event where they had the latest porsches practicing, and the drivers of those modern cars made impressive comments about the trans am......read it a while back so I dont recall the details.

heres another...

http://www.youtube.com/watch?v=ISk3z...eature=related

[RSX302]

My 2 pennies...

With my Incon twin turbo 302, it was perfect. No excessive under hood temps (cast iron manifolds), no turbo lag what so ever (small turbos) and very reliable.

IMO, a small cubed V8 is the best with small turbos. Response great, great all around power and still gets great mpg. (50hp+ more than a supercharger) Full boost by 2000-2500rpm.

Yes..more complex to install with a little more weight.

It all boils down to proper design...(engine too)

Don't get me wrong..superchargers work very well in specific applications.

[John Wright]

avoid the ebay turbo specials...as mentioned its not worth it when something goes wrong. For a couple of dollars more you can get quality stuff. That said there ARE good deals on ebay for turbo piping and connectors.

A single turbo adds complexity to your powerplant...twin turbos add more. The argument for twins has always been a quicker spool up, but a properly sized single can really spool just as quickly, and a larger single is actually more EFFICIENT. Not to mention less expense up front than twins. Twin Turbo sounds cool when you say it though.

As for whether they can stand up to track abuse...watch the following video. I think these guys are in Holland? I know that at least in europe they were a bit of a sensation. Anyway, their 1407 hp twin turbo knightrider style trans am has a few entries on youtube. Its fun to watch the smoke billowing from the tires as it accelerates after turns...lol.

http://www.youtube.com/watch?v=5S4KY5_nO_o

In fact, I believe the car was run at an event where they had the latest porsches practicing, and the drivers of those modern cars made impressive comments about the trans am......read it a while back so I dont recall the details.

heres another...

http://www.youtube.com/watch?v=ISk3z...eature=related

LOL...Polly lays down enough tire smoke where the competition can't even see their driving lines....Love it! In that first vid there is a silver car trying to keep up as Polly drives by and then you can watch it hang the rear way out and then end up spinning.

[Charley Lillard]

Hey thanks for chiming in Charlie.....do you have a car with that set up?....I know you have the ex Tony Stewart Nascar.....how do you like the engine in that?.......is it race gas because Ive sworn myself to building a pump gas engine.

What I have is Jackass. It is a LS9 Corvette ZR1 engine. Makes 703 hp on pump gas and gets over 20 mpg with the ac on. The LS9 can kind of be duplicated by doing a LS engine and adding a similar type supercharger.
Tony Stewart car engine is a race gas only engine.

[aronhk_md]

LOL John...those videos are fun to watch arent they? They abuse that car. Now if you want to see a turbo car that gets the CRAP beaten out of it........you HAVE to watch this...

http://www.youtube.com/watch?v=4TshFWSsrn8

0-60 mph in 1.9 seconds. And they used to say the AC Cobra 427's were fast...lol. Not to mention Ken's driving skills are just inhuman. I just watched it again...next time I think I need snacks and a big screen. I dont think he lets off the gas pedal EVER by the sound of that rev limiter.

[CarlC]

Hey thanks for chiming in Charlie.....do you have a car with that set up?.

Mine is similar to what Charlie describes. It's a lot of fun to drive. An LS3 with a Magnuson supercharger would have significantly more power than mine.

[overZealous1]

they sure can hold up to a beating. but, proper oil drainback and correct fittings and routing of oil lines is a big deal to reliability. keeping your oil cool is another. the oil will get heated even more and will thin out under prolonged beatings. thin enough, and well loss of oil pressure and oil passing by the seals will happen. oil and water cooling the turbo is a good way to go, but adds more fittings and correct routing of hoses. the key to longevity is basically those things. ofcourse a quality turbo, and an engine to handle it are obvious. correct tuning is key also. egt's in the 1600 range is too high for something you want to last. add more fuel.
header style manifolds with turbo on the end of them will need to be supported back to the engine. on every turbo system i do i mount the engine solid. it will keep the flex down in the joints lessening the chance of the tubing coming apart or leaking. all your tubing ends on the compressor side should be bead rolled. use good t-clamps. s.s. gaskets for turbo and w/g or file flushand seal with high heat silicone. a leak will kill spool up and boost overall. a bad leak, will make the opposite turbo make all the boost and compress it back to the other turbo (which will be making it spin WAY past designed speeds).
there is abit more. in other words, don't go cheap on your connections. keep your attention on heat control. do those, and you can beat the hell out of it.

[MonzaRacer]

Well I have been talking to a local guy with a GN turbo, and many of his friends are using Ebay turbos with no ill effects, but lots of people also say you need to get learned up to buy the right turbo.

[aronhk_md]

Well I have been talking to a local guy with a GN turbo, and many of his friends are using Ebay turbos with no ill effects, but lots of people also say you need to get learned up to buy the right turbo.

There are plenty of bad experiences out there to look up. When a turbo goes it can dump metal filings into the oil, which then drain back into your oil pan, which then...

...well, I think you get the idea. If you have nothing invested in your motor maybe its worth taking a shot with one. I know what is invested in my motor, and it isnt worth it to me to save a few hundred dollars by skimping on a turbo.

[protour_chevelle]

Not that I suggest the use of ebay turbos but we have a couple guys up here running the garrett 88mm ball bearing china knock offs and have been going strong for a couple years now. The key, atleast in my eyes and I have confirmed with precision turbos is, -4 feed for oil and a very nice easily flowing and large volume(I use -16) drain is what keeps a turbo alive. The seals are not designed for any pressure, they are simple designed to allow volumes to flow over and lubricate/cool the shaft. One car is a twin 88mm knock off turbo car that has been doing passes in the mid 8 second range for 2 years now. Street driven 3800lb car. Making some serious power!!

I myself abuse the ever living crap out of mine on a daily basis, well in the summer atleast. On low boost, junkyard 6.0l with a baby cam and arp rod bolts on 12psi the car made 600rwhp and 620ftlbs. I went 10.90@130 on 11lbs of boost. No meth, 91 octane pump gas. I had a meth pump die on me so we couldn't turn it up to the planned 18psi I wanted to run.

I say giver!!!! Even masterpower 70mm turbos are a cheaper route and are proven!!! You will not regret it. The car drives on the highway like a stock efi car. Then you pour the coals to it and it grabs the limiter in 3rd nicely and starts paving the road, with drag radials on the back

[shmoov69]

Well I just bought a couple bigger turbos for the car....to "beat on" harder!! Lol!! They are not too much bigger, but they are t-3/t-4 super 57's with a bigger exhaust wheels. Hopefully add around 150 or so HP!! SWEET!!

[John Wright]

proper oil drainback and correct fittings and routing of oil lines is a big deal to reliability

This seems to be a theme in these replies about whether the turbos can be beat on or not.....
it must be worth the extra effort to make sure this is done right to get things to live for a long time.

[Procharmo]

avoid the ebay turbo specials...as mentioned its not worth it when something goes wrong. For a couple of dollars more you can get quality stuff. That said there ARE good deals on ebay for turbo piping and connectors.

A single turbo adds complexity to your powerplant...twin turbos add more. The argument for twins has always been a quicker spool up, but a properly sized single can really spool just as quickly, and a larger single is actually more EFFICIENT. Not to mention less expense up front than twins. Twin Turbo sounds cool when you say it though.

As for whether they can stand up to track abuse...watch the following video. I think these guys are in Holland? I know that at least in europe they were a bit of a sensation. Anyway, their 1407 hp twin turbo knightrider style trans am has a few entries on youtube. Its fun to watch the smoke billowing from the tires as it accelerates after turns...lol.

http://www.youtube.com/watch?v=5S4KY5_nO_o

In fact, I believe the car was run at an event where they had the latest porsches practicing, and the drivers of those modern cars made impressive comments about the trans am......read it a while back so I dont recall the details.

heres another...

http://www.youtube.com/watch?v=ISk3z...eature=related

Twin turbo's will give an amazing amount of power for the money invested. However although people have pointed out the heat issues which can be overcome. The less than precise power output to throttle input can have disastrous effects when on the limit anywhere but a straight line. As seen on the Polly Trans Am video they were able to smoke out the opposition on straight lines. But when they wanted to go faster they ditched the twin turbo's and installed a Procharger F3.

They may have made the same power but had less heat and more control....They went on to achive 252mph.....




They then went on to bring the car over to the US and win the SSCC...Making Big Red look slow with averages of over 220mph on twisty roads..



So in a nut shell. Yes you can beat on TT's but if you want to go fast under control get a fixed relationship between the impeller rpm and your left foot.

[overZealous1]

^ puts an end to things quick when you snap a belt though. which i have done. 1600 miles from home i might add. that sucked!! carried an extra belt with me after that.

i look at the tt as more of a street car set up than all race. sure, big singles in supercharged or turbo set ups make big power, but offer limited fun for the guy going stop light to stop light or wanting good passing power without a downshift. the centrifiguls still only make power in the upper rpms and have similar torque curves to a single turbo. look at a well set up twin, and your bottom end grunt can be outrageous. great for the street car.

[aronhk_md]

I agree that you can achieve a more linear power curve with centrifugals, but dont necessarily agree that its better for any type of racing. The owners/builders of Polly changed setups, but who is to say how they would have fared with the turbos on the car during those events.

I also don't believe that twin turbos are necessarily any better than a properly sized single for low end response. I've seen data that suggests otherwise, and a single turbo is definitely more efficient than a twin design, just as a single prop on a boat can be more efficient than twins.

Oh..............and I have seen and heard of MORE than 1 incident involving belts on centrifugal superchargers. They are terrific power adders, but each type has its own pros and cons.

I think the answer to the original poster's question has been answered though :D