Need Turbo advice
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VWpowa
- Posts: 2
- Joined: Thu Mar 22, 2001 12:01 am
Need Turbo advice
I am starting to throw around the idea of getting a turbo for my beetle after i build an engine. I was thinking 1835, and heads port polish bigger valves. Cam. The works. Wondering what i should set the compression at. And how much boost is recommended. this will be a street motor (weekend cruiser) and will be taken to track. I want at least 130 hp is that obtainable?? Thanks
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Chuck Schneider
- Posts: 345
- Joined: Wed Mar 21, 2001 12:01 am
Need Turbo advice
I wouldn't even waste time with a 1835. The blow by will be massive with 92 cylinders. You have to realize that the cylinder pressure is much higher than naturally aspirated and if you take a cylinder that can't even hold it's shape naturally aspirated and ask it to hold 10 pounds of boost it is gonna blow-by real bad. I just built a 1776 turbo motor with a engle 125, 40 x 35.5 heads and the thing makes like 200 hp. There is no problem with the rings sealing and the power is unbelivable. I would definitly recommend going to 90.5's. Just trying to save you time in the long run. Also there isn't a 1776, unless it is turning 11,000 rpm ,that is makeing 125 H.P.naturally aspirated.
The most you will see naturally aspirated is about 100. You can easilly double the power with the turbo. Hope this helped.
P.S. remember thick wall 90.5 fit right in the thin walled 92's holes.
The most you will see naturally aspirated is about 100. You can easilly double the power with the turbo. Hope this helped.
P.S. remember thick wall 90.5 fit right in the thin walled 92's holes.
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Chuck Schneider
- Posts: 345
- Joined: Wed Mar 21, 2001 12:01 am
Need Turbo advice
I wouldn't even waste time with a 1835. The blow by will be massive with 92 cylinders. You have to realize that the cylinder pressure is much higher than naturally aspirated and if you take a cylinder that can't even hold it's shape naturally aspirated and ask it to hold 10 pounds of boost it is gonna blow-by real bad. I just built a 1776 turbo motor with a engle 125, 40 x 35.5 heads and the thing makes like 200 hp. There is no problem with the rings sealing and the power is unbelivable. I would definitly recommend going to 90.5's. Just trying to save you time in the long run. Also there isn't a 1776, unless it is turning 11,000 rpm ,that is makeing 125 H.P.naturally aspirated.
The most you will see naturally aspirated is about 100. You can easilly double the power with the turbo. Hope this helped.
P.S. remember thick wall 90.5 fit right in the thin walled 92's holes.
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12.70 @ 104
The most you will see naturally aspirated is about 100. You can easilly double the power with the turbo. Hope this helped.
P.S. remember thick wall 90.5 fit right in the thin walled 92's holes.
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12.70 @ 104
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buddy
- Posts: 45
- Joined: Thu Feb 22, 2001 12:01 am
Need Turbo advice
In JMR's performance Guide there is instructions on how to build a 1776 that produces 125BHp at 6000rpm at the flywheel and aprox 118ftlbs torque.
The engine is 90.5, 69mm counterweighted crank, engle 120, 044 53.6cc combustion chamber 8.0:1 compression, 26mm pump Dellorto DRLA's.
These figures where on the JMR's Dyno.
The engine is 90.5, 69mm counterweighted crank, engle 120, 044 53.6cc combustion chamber 8.0:1 compression, 26mm pump Dellorto DRLA's.
These figures where on the JMR's Dyno.
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VWpowa
- Posts: 2
- Joined: Thu Mar 22, 2001 12:01 am
Need Turbo advice
Great Information guys, The 1776 you built where did you get the turbo kit from and is that 200hp at the wheels or at the crank and w/ how much boost. Just a guestimate how much money do you think the engine took you to build motor carbs head and turbo system. This JMR you speak about where can i get more info on this. Thanks for any and all info.
Brian Hunt
Brian Hunt
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buddy
- Posts: 45
- Joined: Thu Feb 22, 2001 12:01 am
Need Turbo advice
130 Bhp is easily atainable from that engine. Compression should be around 7.5:1 max. I have been told that you do not need to port and polish like with a normally aspirated engine on a turbo. You should stick with a mild cam maybe engle 110 or 120. And keep the boost to around 7-9 psi.
On a normally aspirated 1776 engine you can get around 125bhp at the flywheel.
I have never built a turbo engine so I may be mistaken but this is the advice that I have received on a similar engine (1914)
On a normally aspirated 1776 engine you can get around 125bhp at the flywheel.
I have never built a turbo engine so I may be mistaken but this is the advice that I have received on a similar engine (1914)
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Iltis74
- Posts: 71
- Joined: Thu Mar 15, 2001 12:01 am
Need Turbo advice
JMR is for John Maher Racing.
johnmaherracing.co.uk
They sell a performance guide I have been meaning to look at, though from the specs listed in the above post I would tend to agree with Chuck that 125hp is a long-shot. Raises questions of whether or not the cooling fan was hooked up or racing gas was being used. Said it before but in general horsepower numbers are suspect. No one underestimates their motor. But of course as stated I don't have the guide and JMR is highly respected.
As far as compression and such goes, if you haven't built the motor yet it would be best just to figure out who you're going to have build your turbo system and talk about the motor with them. When they know exactly what you expect from your motor they will be able to recommend a cam, head, compression combo to compliment the turbo system to make one nice tidy package.
Good luck and good times with your motor.
johnmaherracing.co.uk
They sell a performance guide I have been meaning to look at, though from the specs listed in the above post I would tend to agree with Chuck that 125hp is a long-shot. Raises questions of whether or not the cooling fan was hooked up or racing gas was being used. Said it before but in general horsepower numbers are suspect. No one underestimates their motor. But of course as stated I don't have the guide and JMR is highly respected.
As far as compression and such goes, if you haven't built the motor yet it would be best just to figure out who you're going to have build your turbo system and talk about the motor with them. When they know exactly what you expect from your motor they will be able to recommend a cam, head, compression combo to compliment the turbo system to make one nice tidy package.
Good luck and good times with your motor.
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Crazylarry
- Posts: 41
- Joined: Sat Mar 17, 2001 12:01 am
Need Turbo advice
I've seen HP numbers being thrown around and there seems to be some difference in oppions. I've noticed that some of the people in this forum are from Europe but the majority are from the good old USA. I've lived in europe for 4 years. While I was there I notice they rate EVERYTHING differently than we do. I.E. octane, HP, ect... just a note to keep in mind.
Larry
Larry
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Michael Ghia
- Posts: 798
- Joined: Mon Jan 29, 2001 12:01 am
Need Turbo advice
Why is 125bhp from a 1776cc motor a long shot?
When I used to work on 356's, our race engine was a 1720cc motor and produced 141bhp. This is on the Machtech JZ rolling road (these guys are seriously into Porsches) which feaures about the most comprehensive setup I've ever seen.
The motor runs twin 44's, a smaller crank pulley and a 9.5:1 compression ratio. The car is built for track racing. 110 bhp can be had from a late 356 motor using stock heads and a pair of 40's with a set of Shasta 1720cc pistons. The cam is a Web-cam.
John has gotten 129bhp from a thickwall 1679cc running 48IDA's. It was a real handful on the street and it wasn't Johns choice to run the 48's, it was the customer who wanted them for the look.
Mike Ghia
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Modification is a form of Art.
When I used to work on 356's, our race engine was a 1720cc motor and produced 141bhp. This is on the Machtech JZ rolling road (these guys are seriously into Porsches) which feaures about the most comprehensive setup I've ever seen.
The motor runs twin 44's, a smaller crank pulley and a 9.5:1 compression ratio. The car is built for track racing. 110 bhp can be had from a late 356 motor using stock heads and a pair of 40's with a set of Shasta 1720cc pistons. The cam is a Web-cam.
John has gotten 129bhp from a thickwall 1679cc running 48IDA's. It was a real handful on the street and it wasn't Johns choice to run the 48's, it was the customer who wanted them for the look.
Mike Ghia
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Modification is a form of Art.
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Chuck Schneider
- Posts: 345
- Joined: Wed Mar 21, 2001 12:01 am
Need Turbo advice
Micheal,
Those numbers are from a full blown race motr that is running race gas and high ass compression. Sure it can be done but is it reality for a street motor. I am giving H.P.figures that will actually live more that a month and not have to turn 10000 to make those numbers.
Those numbers are from a full blown race motr that is running race gas and high ass compression. Sure it can be done but is it reality for a street motor. I am giving H.P.figures that will actually live more that a month and not have to turn 10000 to make those numbers.