Turrrrrbbboooo help

[bgdowski]

So all my friends are pushing me to further investigate a turbo onto my gt. I have no problem with piping fabrication, my only issue is that i want to keep it carb'd, and dont know where to go about getting a blowby that will work on my gt. Can someone please school me on blowbys, what kind i will need, and all that good stuff i may be overlooking

[opelwasp]

Once the turbo pressure exceeds the fuel pressure you will have no fuel delivery. The turbo pressure will also blow the carb seals out unless you enclose the carb in an air tight box and pressurize the whole carb. That still doesn't address the fuel pressure issue though. You will also only be able to achieve about 7-8 lbs of boost. Whoopee

[wrench459]

We've got one of our friends running a TRUE 12.7 C/R with 10 pounds of boost. And oh my does it rock and roll.
It's a blow through with lots of bug juice.

[opelwasp]

On an Opel, using a Weber?

[hrcollinsjr]

Originally Posted by opelwasp You will also only be able to achieve about 7-8 lbs of boost. Whoopee

I remember a friend showing me a HP series book on turbos. The part he pointed out was an article copied from a magazine featured a turbo-ed Manta! It was only running 7 lbs. IIRC and it basically doubled the horsepower. What I particularly liked about the article was that they showed horsepower numbers at various RPM's. The turbo almost exactly doubled the HP at every RPM level noted in the test! I quickly went out and purchased the book and discovered it had been updated and the article deleted for more RELEVANT material. I believe they were quoting a Car & Driver exercise.

Harold

[opelwasp]

Originally Posted by hrcollinsjr I remember a friend showing me a HP series book on turbos. The part he pointed out was an article copied from a magazine featured a turbo-ed Manta! It was only running 7 lbs. IIRC and it basically doubled the horsepower. What I particularly liked about the article was that they showed horsepower numbers at various RPM's. The turbo almost exactly doubled the HP at every RPM level noted in the test! I quickly went out and purchased the book and discovered it had been updated and the article deleted for more RELEVANT material. I believe they were quoting a Car & Driver exercise. Harold

OK so it would have about 125-150 hp. You can do that with a EFI 2.4L easy. Hell you can do that with a NA 2.4L and you'll have tons of torque.

If you want a turbo, do it right and get EFI. It doesn't cost that much. You will also be able to manage the engine better too.

[bgdowski]

so i would need to build a box around a blowby carb? or could i build a box around a larger weber carb? Fuel delivery would be an issue aswell. I would not want to boost more than 8lbs anyway, so no worries.

[opelwasp]

Originally Posted by bgdowski so i would need to build a box around a blowby carb? or could i build a box around a larger weber carb? Fuel delivery would be an issue aswell. I would not want to boost more than 8lbs anyway, so no worries.

8 lbs on a Weber will blow it apart. They are only made to handle around 4.5 lbs. What you are purposing is very risky and the cost/gain benefit just isn't there.

[bgdowski]

Originally Posted by opelwasp 8 lbs on a Weber will blow it apart. They are only made to handle around 4.5 lbs. What you are purposing is very risky and the cost/gain benefit just isn't there.

Fair enough, I trust your opinion. Cost/gain is important for a college kid

[hrcollinsjr]

[QUOTE=opelwasp;183661]

OK so it would have about 125-150 hp. You can do that with a EFI 2.4L easy. Hell you can do that with a NA 2.4L and you'll have tons of torque.

The turbo was added to a stock engine IIRC. And what does a stock 2.4L cost? And it puts out 150 hp, stock?

If you want a turbo, do it right and get EFI. It doesn't cost that much. You will also be able to manage the engine better too.

I won't argue with you the benefits of larger displacement and torque or the EFI being a better way. Your way is going to cost alot more money. You'll have to worry about the transmission and rearend if you decide to "play". I believe the 1.9 w/turbo would be a little easier on the driveline and should be able to keep up with most traffic.

Harold

[Rionart]

The Broadspeed runs 1bar (13psi?) boost on a 1.9 with low comp pistons blowing through a SOLEX in a box...and kicks out 156hp...
Maybe not a lot of power by todays standards, but she can pick up her skirts and boogie...

[bgdowski]

Originally Posted by Rionart The Broadspeed runs 1bar (13psi?) boost on a 1.9 with low comp pistons blowing through a SOLEX in a box...and kicks out 156hp... Maybe not a lot of power by todays standards, but she can pick up her skirts and boogie...

One bar of pressure = 14.7lbs of boost. Something ive learned from hanging out with all these turbo guys at school.

[oldopelguy]

Originally Posted by opelwasp 8 lbs on a Weber will blow it apart. They are only made to handle around 4.5 lbs. What you are purposing is very risky and the cost/gain benefit just isn't there.

There are only two ways to use a carb to build power with a turbo without getting one specially made for it:
-Use a draw-through system (which can't be intercooled and therefore can't make as much power)
-Use a blow-through system and mount the carb inside a box (which fools the carb into thinking you just changed altitude to somewhere near the ocean floor where the air pressure is higher)

Neither of those options has any risk of "blowing it apart."

In my opinion, draw-through systems are pretty much worthless unless your static compression ratio is so very low that you're just getting the engine up to high compression piston standards.

A blow-through system has potential, since the air can be cooled before-hand and you can make up for the fuel pressure issue by mounting the fuel pressure regulator inside the box so it references the same pressure as the carb. There will be dirvability issues, though, since air flow isn't as directly connected to throttle position anymore with boost able to change, but most of them can be tuned out or minimized if it's for a race only car or not going to get a ton of boost. The real trick is going to be timing the distributor with boost coming on, and you'll probably have to swap out to a mechanical only advance and add in a Crane or MSD boost-referenced timing retard module to bring back the advance while under boost.

[opelwasp]

[QUOTE=hrcollinsjr;183667]

Originally Posted by opelwasp The turbo was added to a stock engine IIRC. And what does a stock 2.4L cost? And it puts out 150 hp, stock? I won't argue with you the benefits of larger displacement and torque or the EFI being a better way. Your way is going to cost alot more money. You'll have to worry about the transmission and rearend if you decide to "play". I believe the 1.9 w/turbo would be a little easier on the driveline and should be able to keep up with most traffic. Harold

Stock 2.4 puts out 125 hp. Ad a nice cam for $180 some mild porting work and you'll see 150 hp pretty fast. 2.4L costs $2500.(and you can turbo it if you want later)

Dropping gears with a turboed 1.9 or a stock 2.4 is going to blow out a stock rear end. So playing with any high powered Opel is still gonna cost you.

Building a EFI 2.4L will set you back about $3000. How much will building a 1.9L able to handle a turbo; plus the new turbo, piping, airbox, intercooler, exhaust, and fabrication costs?

A 2.4L will be way cheaper.

[opelwasp]

Originally Posted by oldopelguy Neither of those options has any risk of "blowing it apart." There will be dirvability issues, though, since air flow isn't as directly connected to throttle position anymore with boost able to change, but most of them can be tuned out or minimized if it's for a race only car or not going to get a ton of boost. The real trick is going to be timing the distributor with boost coming on, and you'll probably have to swap out to a mechanical only advance and add in a Crane or MSD boost-referenced timing retard module to bring back the advance while under boost.

In "blowing apart" I mean the gaskets, and diaphragms.

My point exactly about drivability. The cost and effort to do it will out way the gains for a street car.

[baz]

1 word




LAG



it will be murder with a blow through carb as the pipe runs will be so long
you would need to almost floor the pedal at the corner before the one you will be taking to use it on the street

have a look at rallybob's turbo manifold for his project manta (i think it is ) small neat and will respond as well as a modern turbo engined car

[hrcollinsjr]

[QUOTE=opelwasp;183673]

Stock 2.4 puts out 125 hp. Ad a nice cam for $180 some mild porting work and you'll see 150 hp pretty fast. 2.4L costs $2500.(and you can turbo it if you want later)

Is this cam going to be compatible with the turbo?

Dropping gears with a turboed 1.9 or a stock 2.4 is going to blow out a stock rear end. So playing with any high powered Opel is still gonna cost you.

Some people can ruin an anvil with a rubber mallet too!

Building a EFI 2.4L will set you back about $3000. How much will building a 1.9L able to handle a turbo; plus the new turbo, piping, airbox, intercooler, exhaust, and fabrication costs?

WOW, you must be doing all of the machine work and have connections for parts. I helped a friend rebuild a 1.9 and it cost over $2000! Aren't the 2.4L pistons notoriously weak and would need to be replaced? Were rods cast or forged on the 2.4L? Since they're different IIRC from the other rods you're possibly looking at custom rods.

A 2.4L will be way cheaper.

Maybe in the LONG run if you were trying for the max. streetable HP you could achieve.

Harold

[hrcollinsjr]

Originally Posted by baz 1 word LAG it will be murder with a blow through carb as the pipe runs will be so long you would need to almost floor the pedal at the corner before the one you will be taking to use it on the street

A GOOD driver should be looking ahead and making decisions early so what's your point? I'm all for the remote mount turbos also.

Harold

[opelwasp]

[quote=opelwasp;183673]

Stock 2.4 puts out 125 hp. Ad a nice cam for $180 some mild porting work and you'll see 150 hp pretty fast. 2.4L costs $2500.(and you can turbo it if you want later)

Is this cam going to be compatible with the turbo? Sure if you get a turbo cam

Dropping gears with a turboed 1.9 or a stock 2.4 is going to blow out a stock rear end. So playing with any high powered Opel is still gonna cost you.

Some people can ruin an anvil with a rubber mallet too!All too true

Building a EFI 2.4L will set you back about $3000. How much will building a 1.9L able to handle a turbo; plus the new turbo, piping, airbox, intercooler, exhaust, and fabrication costs?

WOW, you must be doing all of the machine work and have connections for parts.Nope, bought parts from Summit and OGTS and machine work by local shop except for the crank I helped a friend rebuild a 1.9 and it cost over $2000! Aren't the 2.4L pistons notoriously weak and would need to be replaced?305 chevy pistons Were rods cast or forged on the 2.4L?stock forged Since they're different IIRC from the other rods you're possibly looking at custom rods.

A 2.4L will be way cheaper. Cost me $2500 to build my Legere Spec 1.9 to 2.4

Maybe in the LONG run if you were trying for the max. streetable HP you could achieve. Isn't the "long run" the point? Unless you like rebuilding your engines.

Harold

[hrcollinsjr]

Originally Posted by opelwasp A 2.4L will be way cheaper. Cost me $2500 to build my Legere Spec 1.9 to 2.4

You didn't specify which 2.4. I know, I didn't ask. I "assumed" you were speaking of a "real" 2.4L not a "home brewed" 2.4L. Aren't you glad Bob L. did all of the preliminary work making it easy and cheap to come up with a combination that would work? I do have a question about reliability though. This engine will hold up for the short run. Will it last as long or longer than a stock 2.4L Opel engine? For some people 100K miles is plenty because they'll never come close to putting that many miles on their cars.

Maybe in the LONG run if you were trying for the max. streetable HP you could achieve. Isn't the "long run" the point? Unless you like rebuilding your engines.

I don't put anything together that I have any questions about whether it will hold up or not! I can't afford to! Ask RallyBob how many engines he's lost. My guess is several! If you build enough and push the limits far enough you're going to loose a few. With that being said we've all benefited because he has pioneered a LOT of stuff so it's pretty much proven to work IF we follow his guidelines.

Harold

[Gumby]

Originally Posted by opelwasp Stock 2.4 puts out 125 hp. Ad a nice cam for $180 some mild porting work and you'll see 150 hp pretty fast. 2.4L costs $2500.(and you can turbo it if you want later) Building a EFI 2.4L will set you back about $3000. How much will building a 1.9L able to handle a turbo; plus the new turbo, piping, airbox, intercooler, exhaust, and fabrication costs?

Buying a used engine will set you back even less. That 2500 is for a used engine with no manifolds. The stock 2.4 put down somewhere close to 125hp with the 2.4 injection system. Realistically I wouldn't expect to see the same if you are running a different manifold (N/A applications only).

Originally Posted by opelwasp WOW, you must be doing all of the machine work and have connections for parts.Nope, bought parts from Summit and OGTS and machine work by local shop except for the crank I helped a friend rebuild a 1.9 and it cost over $2000! Aren't the 2.4L pistons notoriously weak and would need to be replaced?305 chevy pistons Were rods cast or forged on the 2.4L?stock forged Since they're different IIRC from the other rods you're possibly looking at custom rods. A 2.4L will be way cheaper. Cost me $2500 to build my Legere Spec 1.9 to 2.4 Maybe in the LONG run if you were trying for the max. streetable HP you could achieve. Isn't the "long run" the point? Unless you like rebuilding your engines. Harold

The stock 2.4 pistons are not suitable for boosted applications. The rods are forged but the piston's aren't. They were a high quality casting by Mahl if my memory is correct. They are good for just driving around but tend to fail with high rpm use (anything beyond 6k I am told puts them at risk).

A while back Demon carbs offered a completely sealed carb that was suitable for both types of carb setups for forced induction. Granted these carbs were designed for a V8 but well into the 2k price range. Even at half that price for a 4cyl version you'd be better off with an EFI setup.

Boost with a carb is possible but it comes along with a few headaches. You haven't really said what your ultimate goal is for this car. If you are aiming for appreciable power (OH momma that's fast) keep in mind the clutch, transmission, and rearend need to be reworked for reliability. I am not saying any of these parts won't work... it is just a matter of how long you want them to work under that kind of stress.

[wrench459]

Originally Posted by hrcollinsjr A GOOD driver should be looking ahead and making decisions early so what's your point? I'm all for the remote mount turbos also. Harold

Squires Turbo Systems - Universal
I've been looking at these they sound interesting. No oil feed and drain lines because of the lower operating temp. Lower heat transfer to the intake track. Almost sounds too good to be true.

[opelwasp]

Originally Posted by wrench459 Squires Turbo Systems - Universal I've been looking at these they sound interesting. No oil feed and drain lines because of the lower operating temp. Lower heat transfer to the intake track. Almost sounds too good to be true.

And turbo lag a year long.

[Redskinsjbs]

You guys know that there is another way of cramming air into an engine... You could use a supercharger.

Just a thought. I have no idea how feasible that would be, but hey, what is this place for, right?

[RallyBob]

Originally Posted by opelwasp And turbo lag a year long.

Actually the Squire's kits aren't that bad, at least not as bad as I first perceived. They actually size the turbos on the small side, plus they use no intercooler due to the length of the plumbing, so they spool reasonably well. However they do use a scavenge pump and pressure lines to bring oil to the turbos. The concept is sound, and they make good power (I saw over 600 whp on a GTO twin turbo), but the remote oil lines scare me a bit. If you break one, the turbos AND engine are toast. FWIW.

But I wouldn't want to try this system on an Opel unless the engine was a bit stronger in stock form, the low compression engines just have no exhaust pulse energy and would have trouble spooling up a pinwheel that far back...