Pros and Cons of TWIN TURBOS ON A MODIFIED 20B

JayDee · December 10, 2011, 06:05:58 PM

I have never tested it, but from people I know with skyline and supra, they notice no difference in spool, with 2 turbos, obviously if changing intake etc is not a fair comparison.
3 bar I don\'t know about that, it should be back on the dyno in the new year, with some Xmas presents lol

Quote from: Grant Monkhouse;802095Need to edit my post. 2 turbos giving the same equivalent lb/min air flow isn\'t necesarily going to yield the same HP.

Mir · December 11, 2011, 12:44:09 AM

Hi Guys

Thanks for the input. Spoke with pip today for over half an hour and so. We discussed numerous options and at the end, we came to the conclusion that, A single turbo is more suitable than a Twin turbo set up. We considered many things in reaching to this conclusion and all the things were dependant on the "reliability" aspect. Pip suggested that, if I want a reliable engine, then single is alot better solely because, there is less room for something to go wrong.

I told him about the 475 and 595 Turbos and he sid he will get back to me on this.
So this is so far I/we got to. I will be posting more updates as the time/project progresses further.

Cheers
Mir

m1tch · December 11, 2011, 09:46:44 AM

I guess keeping it simple is the best plan, its one of the reasons why I have an FC, single turbo as standard, whereas the FD always seems to have issues with its boost solinoid for the secondary turbo etc and its a bit more complicated to sort out.

Grant Monkhouse · December 11, 2011, 01:29:15 PM

did you email him the spec sheets i sent you? that will help him on deciding what is best for you.
also have you rang the guys at AET?

Quote from: Mir;802125Hi Guys

Thanks for the input. Spoke with pip today for over half an hour and so. We discussed numerous options and at the end, we came to the conclusion that, A single turbo is more suitable than a Twin turbo set up. We considered many things in reaching to this conclusion and all the things were dependant on the "reliability" aspect. Pip suggested that, if I want a reliable engine, then single is alot better solely because, there is less room for something to go wrong.

I told him about the 475 and 595 Turbos and he sid he will get back to me on this.
So this is so far I/we got to. I will be posting more updates as the time/project progresses further.

Cheers
Mir

Mir · December 11, 2011, 02:56:18 PM

Grant sorry was really busy with seminars!! I will do this tomorrow! Nah I have not rang them as I was way too busy

! I will do this tomorrow!

Cheers

wolfie1 · December 11, 2011, 09:59:47 PM

Quote from: m1tch;802004Stage the turbos?

does really make a huge difference and could you run this on a rotary safely? cause that looks awesome!

m1tch · December 11, 2011, 10:05:29 PM

The boost will be too high as the first turbo say goes from 0psi to 14psi, the 2nd turbo then takes the 14psi and ups it to say 28psi, good for high boost, but bad due to the lack of intake charge cooling between the turbos, ie the second turbo is compressing already very hot air from the first turbo, its mainly used on tractor pulling rigs that run massive boost or large diesel trucks.

Grant Monkhouse · December 11, 2011, 10:13:21 PM

Quote from: wolfie1;802188does really make a huge difference and could you run this on a rotary safely? cause that looks awesome!

not really, if thats what i think it is, a compound turbo setup, it will be producing huge amounts of boost.

the first turbo compresses the incoming ambient air, then the second turbo compresses the air again.

there is a thread on rx7 club where someone is building a twin setup, but using a supercharger, for the low rpm range, which then switches over to a turbo for the mid to upper rev ranges by means of some magic gubbins in the pipe work, the super charger is small and will work really responsively in the low rpms but will run out of puff as the engine gets going. i think the supercharger gets turned off soemhow after point x is reached and the turbo takes over. so the air isnt getting compressed twice like in the setup above.

i may be wrong though.

compound turbo charging is normally found on diesel engines or compound supercharging is found on huge compressors.

wolfie1 · December 12, 2011, 08:38:20 PM

thanks for the explanation

Ada7 · December 12, 2011, 08:48:55 PM

Mir i maybe missing something here but why are you looking to change your set up again when from what i can remember you only ran the turbo you had at 0.7 bar. Why not get the boost turned up on that, sort the mapping and fueling and then you car will be ridiculously fast.

Adam

Mir · December 13, 2011, 12:11:32 AM

Quote from: Ada7;802291Mir i maybe missing something here but why are you looking to change your set up again when from what i can remember you only ran the turbo you had at 0.7 bar. Why not get the boost turned up on that, sort the mapping and fueling and then you car will be ridiculously fast.

Adam

You are right Adam, but I am suffering from a bug called "I cant be satisfied" lolll I would have done so, but it would have not availed me anything, because, the manifold was too thin for the power level I was after.

I just couldn\'t justify going to WGT (200 Miles each side) twice, because according to the famous tuners, I was just waiting for the manifold to blow up. Hence, I decided that, I would just start a fresh, sell the turbo set up, build a new manifold with T6 flange and sort it out once and for all (as if this is ever gonna happen:Hammer).

I can see your point, but then I was just thinking what would be the best bet, knowing that its winter now, I decided to take a dip:Thumbs-up

Cheers Mate
Mir

JayDee · December 13, 2011, 01:48:26 AM

How did the manifold look once you took it off?

Quote from: Mir;802343You are right Adam, but I am suffering from a bug called "I cant be satisfied" lolll I would have done so, but it would have not availed me anything, because, the manifold was too thin for the power level I was after.

I just couldn\'t justify going to WGT (200 Miles each side) twice, because according to the famous tuners, I was just waiting for the manifold to blow up. Hence, I decided that, I would just start a fresh, sell the turbo set up, build a new manifold with T6 flange and sort it out once and for all (as if this is ever gonna happen:Hammer).

I can see your point, but then I was just thinking what would be the best bet, knowing that its winter now, I decided to take a dip:Thumbs-up

Cheers Mate
Mir

Mir · December 13, 2011, 11:38:17 AM

Quote from: JayDee;802347How did the manifold look once you took it off?

Jay, it looked cooked!!!!! You were right what you said the other day when I came over to see you;)

In my opinion, the manifold was not ready for the action!:Viking

I have taken several photos of it just for record purposes.

Mir

Grant Monkhouse · December 13, 2011, 03:57:57 PM

Post them up. What was the Mani made out of? What are you making the new mani out of?

Any particular reason for choosing a t6 over a t4?

Mir · December 13, 2011, 04:46:52 PM

Grant the pics are embarrasing, so cant do that lolll. T6 as advised by many and I can see a good reason behind it unless you can do me a comparison of T4 and T6? Initially, I was going with titanium, but the person who was going to work on it is off sick for quite sometime. So, I went to someone else and he said he cant do titanium, hence, I am thinking to go back to cast iron or choose something better!

The car is off road and she will be on road arround May or April next year. Big plans for the car at the moment.

Do you want a to do list?

Mir