Which Turbo?

Gene FJ20DET · Posted: Thu Oct 16, 2003 5:12 pm Post subject: Re: Which Turbo?

rev a shit load harder

parts are easyer to get
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Loz · backyard mechanic Joined: 05 Oct 2001 Posts: 943

Well they are actually more efficient to be on boost all the time, like big trucks, they are always on boost and its to do with better efficiency. Otherwise they would just put bigger engines in.
The main reason they MAY chew more fuel is that you have the power there alot more and this provoks a heavy right foot.
Both sizes have their drawbacks.

The best way to choose the right size is to decide on the max HP you want to make and then select the smallest turbo that will do the job. And depending on you requirements you will either get a laggy one or a non laggy one.
Either/or, personal preference.

Poida · Posted: Fri Oct 17, 2003 4:49 am Post subject: Re: Which Turbo?

I tend to agree with FYINLoW... It's a hell of a lot to spend on an engine. If I were about to fork out 8K I'd not be leaving it up to some other person to choose what I need. Surely you have some idea about what you are getting or are you just writing blank cheques? Send me some this way and I'll build you an engine!

The reality of the whole thing is unless you are going to spend a fortune on agreed value insurance for your car, it's only going to be worth the market value according to the guide books insurance companies use. This means when I crunch head on into your 8K engine, stamping the water pump impeller into No 1 piston, you are going to get the market value that my prang damage insurer will pay. No more. Now looking at the guide on www.carsales.com.au which is provided by "redbook" I valued as an example a TG SL/X sedan at $2900. That is the maximum you could expect to get for your written off TG SL/X. If you weren't satisfied that my insurer had paid the true value, the only option you would have is to sue me for the remaining value in a civil case.

So by all means have fun and build the car you like but be aware that even if you are spending a fortune on it, it's still only worth as much as the insurance guidebook suggests.
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Gemini Driving Yobbo · petrol head Joined: 26 Feb 2002 Posts: 3897

im leaning towards a sohc now mainly coz of the parts and they rev better

Gene FJ20DET · Posted: Fri Oct 17, 2003 12:48 pm Post subject: AARRGG, to many words to read

but yeah. my engine is worth about $9000. its not hart to spent that kind of money, if u use quality parts u have to pay for them
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Loz · backyard mechanic Joined: 05 Oct 2001 Posts: 943

My engine has cost alot too. But still insurance is only $1400 with an agreed value of $10000. And I get to keep the wreck for a very small fee in the result of an accident.

Gene FJ20DET · Posted: Fri Oct 17, 2003 1:41 pm Post subject: Re: AARRGG, to many words to read

whos that threw?
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Grant · rice boy Joined: 11 Jun 2002 Posts: 28

Once again loz has a valid point, decide how the car is to be used, max HP etc you want, is it an every day car and of course life span?, can you afford maintanence on a monster engine? Just out of intrest, i am running a 4ZE1, with a single throtle (not that isuzu twin thing), RX7 injectors,custom inlet manifold, GT28 turbo (with a 36mm restrictor, needed for the catagory of racing im involved with)and Autronic computer. Figures are 300+hp,400+nm(I dont want to give away to much), all starting at approx 2000rpm and peaking at approx 5500rpm all well under 20psi. This kind of combo would be good for 400+hp, without the restrictor. In all it has cost me a little over 10 grand. So after such a long post, in sort, do some serious homework, be sensible(ish) and you can achieve good hp with many years of driving. NO SHORTCUTS.

Loz · backyard mechanic Joined: 05 Oct 2001 Posts: 943

Vigil

http://www.vigilins.com.au/vigil/products/default.asp

$500 for third party aswell.
I havent actually got it yet but been quoted approx. those figures twice now

Loz · backyard mechanic Joined: 05 Oct 2001 Posts: 943

Exactly...Fuck the shortcuts, or you'll pay later anyway.

Gene FJ20DET · Posted: Fri Oct 17, 2003 2:07 pm Post subject: Re: AARRGG, to many words to read

WOW $1400 full comp? fuck thats good
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Loz · backyard mechanic Joined: 05 Oct 2001 Posts: 943

Yep thats what it was. Best quote I have ever had.

Ben Wight · backyard mechanic Joined: 04 Oct 2001 Posts: 946

dohc isuzu engines are still 8 valve heads, same as a sohc.

put the factory injection and exhaust manifolds from a twin cam 1800 onto a sohc 1800, and give them equal compression ratio, and they will probably make around the same power.

Ben

Gene FJ20DET

ouch!! mine was $3100 full comp, $15000
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Poida · Posted: Sun Oct 19, 2003 7:24 am Post subject: Re: Which Turbo?

Well I'm not that familliar with the twin cam heads but I'd expect them to be a little different in the port layout than the SOHC. Correct me if I'm wrong.

The original G180W was designed around the Lotus-Ford twin cam engine and was fitted with twin solex carbies mounted to the head. In the Ford engines the carbies mounted to an integrated manifold cast as part of the head. From memory the same type of arrangement is utilised on the Isuzu engine. I'd expect the same stud pattern to have carried on with the fuel injection heads.

I'm sure you can enhance the SOHC engine enough to get it well beyond what it is in stock trim but the main features of the twin cam head which set it apart are the type of combustion chambers which you don't have in the SOHC head.

Can anyone verify that the twin cam manifolds will bolt up to the SOHC head?
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I try to tackle one day at a time, but often several days attack me at once.

(The views I present are my own and NOT necessarily of the administrators or other members of this site.)