Turbo or Nitrous?

M

MandarinaRacing

Famous Member
OK, since turbos are the rage on the forums right now, and after hearing about drag-200stang's ride I want to ask something...which is better TURBO or Nitrous ? Other than the obviuos that N2O is not power on-demand and bottle re-fills....which has more power generating potential. Both would require major mods to the engine, I'm not talking about 5 psi, or 50 shots, I want to blow the doors of this thing !!!!!
Comparing to some of the big boys in drag racing, supercharged pro-mods are doing better than their nitrous counterparts, also in NMRA almost everybody has gone to blower or turbos (except for Glidden) heck even the import crowd, all the PRO imports use a turbo.

Comments?

Alex
 
Use both!

Turbo
A turbo at 9 pounds will give up to 1.6 times the original unturboed horsepower if the fuel air mix is well distributed. If you can give it 14 pounds, you can get almost twice the power of a non-turbo engine. An N02 set-up will give a 1.5 times hp multiplyer if the engine is built to cope with the termal load.

(Thermal Stress Breakers:-Forged pistons perhaps, or very good cast pistons with a chamber with no negative deck register and no sharp edges at the anular gasket interface, and no sharp edges at the valve seat, and exhast valves and gides which can transmit the thermal loads into the water jacket. Composite gaskets are better than steel or tin in a turbo application, thicker cylinder bores are best. O ringing should be looked at. Roller rockers to stop side loading the valves are needed when the cylinder pressures are only very high. The valves can spot weld themselves to the head under huge loads.)

A 200 Ford engine has no prpblem giving 165 hp in a 2-bbl log engine with the right ~ 265 degree cam. A street turbo will cope with cams up to 280 degrees with the right turbo housing size. 9 pounds can therefore give about 265 hp without drastically increasing the overall stress to the engine. And there are minimal mods needed at that level. To run 14+ pounds and get over 320 hp, you need to start ticking off all the mods above to run it safely without detonation or termal load hitting the recipricating components. What people just don't understand is that a turbo engine responds to the same performance mods that a non turbo engine responds to. The wilder cams can operate on a turbo as well, but its limited by:-

a) drivablity/surge of the turbo at low rpm. A race engine can cope with a turbo way too big if its never at anything but wide open throttle. A street car will destroy itslef.

b) the duration on over lap and especially on exhast must be minimised. You can still run very wild cams on turbos, but often you back off on totla duration. On a Ford Six, you need to go a little wilder than you would on a Pinto or Mustang 2.3, as the exhast is restrictive.

Nitrous
Shove a 150 hp Nitrous kit on it, and you have 400 hp. So long as each cylinder gets an even lick of fuel and air, it will work fine.

The pistons, if very good cast pistons, or some of the forged items, could cope with that.

Read David Vizard 1988's books on turbos and nitrous. His work on

1.the V8 powered Morris Minor with a Buick Rover 3.5 liter V8 with Porsche 928 Mecahnical injection, No2 and twin turbos is simply a legand. The guy Nik who built that car was no millionaire, and the car did low 11sec quarters while remaining perfectly streetable.

2. Racer Walsh and Jim Flynns Turbo 1973 Pinto 2000. A 450 hp drag racer which just killed everything in its class.

3. Turboed Minis and Austin Metros. Admittedly, his involvement with these turbo engines was minor, but his information on how to avoid the big bang and torching your investment is vital. And 200 hp from an A-series 78 cube, 1275 cc 3-bearing 4-cyl is of some note, don't you think?


The Turbos, nitrous and giant killing perforamance.It is the answer.

If you read up on this stuff, you'll be able to budget the dollars for it, as you'll be famous for being able to run a six way past the big boys. V8 and four cylinder owners just don't understand how strong that little 200 engine is. (Wait for the 300 boys to cotton on to this!)
 
FWIW the IHRA allows the giggle-gas fed Pro-Mods a much larger engine displacement than the supercharged ones. It's not apples and oranges though, the forced induction cars burn alky and the nitrous breathers run gasoline. Still, in an all-out motor, I'd say there's more performance potential with a blower. Which type of blower will work best has a lot to do with engine type, chassis weight, drivetrain and a ton of other factors but, in general, I'd sat aturbo has an advantage on the belt and/or gear driven types.
 
XE, all this turbo stuff is very confussing, the more I read the worse it gets, it's frustrating. Import killer used a .82 exhaust turbine (Buick GN T-type) on his 200, according to Turbonetics an engine from 150 to 200 ci would need something between .63 and .82 exhaust. Problem is that I've been trying to find a used turbo here and most are from imports, I don't know if any of these would work, they seem to have very small A/R ratios. So I'm back where I started, not knowing what to chose. Bear in mind that all this turbo stuff is very NEW to me, and I'm still learning, it be good if I could find an import turbo that could work for a 200 six.

Alex
 
According to Ray Hall this is what I need ...
LinkPhoto


Alex
 
Please do your own math and look at the maps yourself. Do NOT trust that calculator.


-=Whittey=-
 
Ray Halls turbo site has, unhappily for me and all here, been updated to work with only the new Garret AiResearch ball-bearing turbos, not the good old T03 and T04 AiResearch turbos we can find at the swap meets.
Major Bummer!

In the old days, I used this to prove that a TO3 60 trim is all you need for a low-pressure turbo on a 250 I6, and it'll be plenty for the 200, no worries. 10 psi and 266 hp is what you'll get, not the 333 hp my run yielded.

http://www.hpphoto.com/servlet/LinkPhoto?GUID=469252d3-a260-6c4f-5cc8-756b6e4939f5&size=

Here is where to find the maps

http://64.225.76.178/main.htm

These days, if you click on the same link like you did, all you get is the newest Ball Bearing turbo. :cry: This is so the poor young ricer punter lines the suppliers pocket with new money on a new turbo. It's not for 'Raiders of the Lost Part' like us guys.

Something like the T25 is a Toyota spec turbo, and there are a bewildering aray of new turbos to find from Jap imports. Beware, all Jap turbos are sized for response, not peak power. Examples are the Mitsubishi Turbos, the Toyota CT26 series twin turbo's (too small, not enough room fro proper boost control with the integral waste-gate), and all the other BS set-ups which get ripped off and replaced with a good TO4 anyway. Exception is Mazda with there RX-7. If you keep looking for good used turbos for lots of boost, you end up wanting either TO4's, or the latest GT40 turbo used in the XR6 Turbo Falcon. Things like T72's are for those lined with 24 carat pockets.

In the States, the trick is to check the ones you can find. 300zx Turbos have great turbos, TO3's with large 0.80? AR's. Rx-7 Turbos are good too.

In practice, a T03 in the right trim can cope with 370 hp tops if has an internal waste gate. Past that, it'll overspeed.

Have a look at this site for all the info

http://www.turbocalculator.com/how-to-read.html

Let's show you what happens if you were silly enough to use a 45 trim T03 from a little Diesel French Peugeot or VW.

Here is a TO3 with 45 trim map.

LinkPhoto


What you do is find what your orignal hp is BT (Before Turbo), and then find how much boost you want to run. If its 10 psi, then just do this calculation:-

10+14.7 = 1.68 times the orignal power, the Pressure or Boost Ratio (in theory)
__14.7

You draw a horizontal line at 1.68 (it will most liely be about 1.5 in practice, 'cause the air heats up when boosted), and then suss out how much air the engine can consume. All the graphs use either lb/minute flow rate, Hp, or CFM. Multiply Lb/Min by 10.86, and you get flywheel hp.

You are looking at about 160 hp with that turbo if its operating in the 70+ precent efficeincy zone. That is way too small. It may pump up to 24 lb/min of air at about 24 psi of boost, but it'll be doing 154 200 rpm, and will kill itself.

What you are looking for is:-If you have about 165 hp, then 10 pounds should add up to around 265 hp. Thats a 265/10.86, or 24.4 lb/min air requirement. Any graph needs to have that reading in its epicentre at the 70-74 % efficency isobar.

If you add a nitrous oxide system to a turbo engine, you will use one-third the NO2, and get a huge boost. Most kits producing 150 hp extra hp unaspirated will make much more boosted. If you drill the turbo, you can itercool it with NO2, and then add another nossel where the Holley is. A blow-through makes more power, has less mixture segregation, and is able to cope with lots of boost if it is boost referenced or enclosed in a box.

David Vizards ancient books have all the answers. One book, regarding sohc Pinto/ Taunas/Cortina/Capri engines which could rev to 7000 rpm. He touched on turbo sizing in the 1980's, and he suggested T04's on everything for safety, as he felt most guys would end up turning up the wick, and running hi-stall converters or 6:1 diff ratios.

David Suggested:-

a T04B with AR from 0.58 to 0.69 for the street.
The 0.58 AR is an TO4B E1 trim, I think. Okay for less than 220-250 hp.
The Ak Miller TO4 with a 0.81 Exhast trim gave about 320 flywheel hp (250 rwhp) at 8:1 compression in a 18 psi boost engine with a draw through 500 cfm Holley 2-bbl, and 300 duration, 480 thou lift cam on a 2000 cc Pinto engine in 1977.
T04B V-1 trim can do 550 hp. Very important you know that these have in some cases, they have been supperseeded

Available four-bolt Garret AiReserch items are:-
T3 Super 60,
T04B S-3,
T04B V1/V2,
T04B H-3
TO4E "40","46","50", "54","57","60" = 280 to 560hp
TO4S = 360 to 630hp
TO4X = 400 to 660hp
TO4X2 = 550- to 930 hp
TS04

Note: The T3 was used starting on the 240 turbos and continued through the 1989 700 turbo cars. It became water cooled in the 1987 model year and most replacement T3s were water cooled. In Australia, it was used in aftermarket 255 hp EFI Falcons, and Holden Commodres with the RB30ET 200 hp engine

Turbonetics derivatives,0.58, 0.69, 0.70, 0.81 or 0.96 AR, 550 -950 hp
Some cross-bread variants here with four or three bolt housings
T-58
T-61
T-64
T-66
T-70
T-72
T-76
T-88
T-91
T-100
T-105

Other Turbonetics halfbreeds
60-1 and 60-2 Series ones are T04 variants with high-efficiency intakes.

BEWARE! Some people call the T03 and T04 T3's and T4's

Common call names for the Rayjay or TRW turbos, which are three bolt, not four bolt at the flange, but can be fitted to four-bolt manifolds with a Turbonetics adaptor are:-

B-Flow for 150-175 hp AR is about 0.40.
F-flow is 175 - 350 hp, perhaps 400 hp tops
E-flow is a 400 plus machine.

GN Turbos, with 0.63 to 0.82 AR's are based on these I believe, as they are three-bolters.


The other ones which are out due to cost, size, or newness are these:

GT15
TBO25
TBO2/22
VNT15/22
TBO28 ceramic turbine
TA34/TB34
TBO3
Brand new TO4B and TO4E
TA45
GT25, found on Volvo 940SE, and maybe a few other 700s and 900s.
GT30,
GT35
GT42
GT24/45
GT40 (Falcon XR6 Turbo)
TD04 Mitsubishi, found on the Volvos made from 1987 to 1990
TD05 Mitsubishi, found on some Volvos
TD08H Mitsubishi
TD05H-16G (Mitsubishi, good if you can get one)
TD05H-16G (from the Mitsubishi Evo)

The higher the RPM, the bigger the AR number will have to be.
Our cars will never run to 7000 rpm plus unless its a drag only car. I'd say a T03 with a 60 trim will do okay, because I've seen it do 200 -360 hp on Commodre and Falcon Turbos in Australia. This has to be a split pulse turbo with integral wastegate. Thats about 333 hp on a 250 six wound out to 10 psi. The bigger the AR and 'trim', the more hp it will make. If you size too big with a mild cam, it will surge and break at low speed. If you over cam to a maximum of 280 degrees, you will find bigger turbos can be used easily.

Hope that helps. Use the turbo you can find, and find the turbo curve as Whittey says. If it is just a turbo, tell us the stock power before turbo, and then we will sort a trim out for you for the boost you are looking at. If you are going to then run nitrous, you'll need to go for the TO4 without question. Although nitrous doesn't increae air consumption, it does make the turbo spin at a rate it was never designed for, so you then have to go bigger.

Lot's of guys here to help you out, and if someone has better information, you can bank on getting it before you lay out some money on one.

Regards,

Deano
 
I 'm glad I dont have to decide between the two. They both have strong and weak points. If you decide to stick with NOS put a fogger system on it. You might check out my site even though its a diffrent brand. NOS doesnt care what brand it is :D

www.mighty6.com

Steven
 
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