S16 With Gti-6 Exhaust Manifold.... This Weekend

[petert 583]

You can't.....

 

How bad is the mismatch PeterT? Is all this work going to be for nothing?

 

Read this thread:

 

http://forum.205gtidrivers.com/index.php?s...ic=42839&hl=S16

 

The difference between the overall width of the ports is 12mm, or 6mm per side. Making the exhaust gas turn 6mm over a short distance isn't a smart thing. It needs to be a gradual change, ideally around 6 degrees from memory.

 

I don't think there's any evidence to suggest an cast S16 manifold is any more restrictive than the fabricated 1.9L manifold. Until someone does a back to back flow test we're only guessing. The S16 outlet and downpipe is a full 2.5" compared to 2.25" on the 1.9L.

[maxi 36 1 Cars]

Read this thread:

 

http://forum.205gtidrivers.com/index.php?s...ic=42839&hl=S16

 

The difference between the overall width of the ports is 12mm, or 6mm per side. Making the exhaust gas turn 6mm over a short distance isn't a smart thing. It needs to be a gradual change, ideally around 6 degrees from memory.

 

I don't think there's any evidence to suggest an cast S16 manifold is any more restrictive than the fabricated 1.9L manifold. Until someone does a back to back flow test we're only guessing. The S16 outlet and downpipe is a full 2.5" compared to 2.25" on the 1.9L.

 

 

Lets get it on the flow bench, quick! Matt, fire the old girl up!!

 

 

Could prove some real good results!

 

Maxi

Edited January 16, 2006 by maxi

[DrSeuss 0]

Could you not chop the ports off as they start to oval and weld them to a custom flange and formed ovals? Obviously this isn't just a modification and requires significant amounts of fabrication. But judging by your post Peter it seems the only sensible way of attacking the problem.

 

With flange's being so cheap and the possibility of reangling the manifold while fabricating the port formers its still cheaper then paying for a custom manifold.

 

You've also confirmed my downpipe and exhaust are probably going to form a restriction in terms of power, time to upgrade to a 2.5" system when money permits.

[Robsbc 0 1 Cars]

A cut and shut job has been executed and the manifold fits onto the car....

[Revla 2]

Just to say, all up and running now......pics to follow, mapping now next month.

 

Then the master cylinder gave up on Saturday.... terrific

 

Cheers

 

Trev

[maxi 36 1 Cars]

Oh s*it, bad luck Trev!!!!

 

I must everyone, went out in this the other day and it did spur me on to get mine all sorted. It goes very well considering its only running a map for a std S16.

 

Cant wait to see what it makes on the rollers!

 

Maxi

[Revla 2]

Cheers Maxi,

 

I can't wait either..... should be good.....

 

 

Just suspension to sort, then its the (almost) perfect Pug...

 

Then to sort the Goodwood.....

[Revla 2]

Hi people....was at Emerald yesterday

 

Graphs to follow, but it made 201.9 bhp and 158.7lbft of torque......

 

Lovely!

 

Cheers

 

Trev

[Dom9 2]

That's a good result... I'm itching to get my S16 done now...

[Shevy 4]

Excellent result there.

 

Have you had any headwork done to achieve that result ?

 

Whats your full engine spec ?

[Revla 2]

Excellent result there.

 

Have you had any headwork done to achieve that result ?

 

Whats your full engine spec ?

 

It is a S16 from a Citroen ZX:

Uprated oil pump spring (really helps!)

 

Catcams: 4900339 & Verniers

 

Three angle valve seats

 

GTi-6 manifold

 

Jenvey 45's

 

Emerald ECU

 

Cheers

 

Trev

[Robsbc 0 1 Cars]

S16.pdf

 

Trev's graph of 2.0 S16 plus bodies + mods v 2.0 AVAC, K & N & GRP N middle box.

 

He's on 40mm trumpets

Edited February 21, 2006 by Robsbc

[Revla 2]

S16.pdf

 

2.0 S16 plus bodies + mods v 2.0 AVAC, K & N & GRP N middle box

 

Thanks Rob...

 

My graphs from yesterday.... and standard engine from previous power run.

Edited February 21, 2006 by Revla

[Robsbc 0 1 Cars]

And here's one for Jon Murgie interest 40mm v 75mm trumpets....In the end Trev decided to choose 40mm for his engine....

 

Dotted line represents 75mm trumpets

 

 

Trumpets.pdf

[maxi 36 1 Cars]

Well done trev, f***ing brilliant result!! I better get mine some bodies now and get some proper power out of it......

 

Whats does it drive like??? Is it still quite powerband'y or is it smooth power right through the rev range? Does it feel a lot quicker than when you took me out in it?

 

Maxi

Edited February 21, 2006 by maxi

[petert 583]

It is a S16 from a Citroen ZX:

Uprated oil pump spring (really helps!)

 

Catcams: 4900339 & Verniers

 

Three angle valve seats

 

GTi-6 manifold

 

Jenvey 45's

 

Emerald ECU

 

Cheers

 

Trev

 

An interesting thread, as I'm currently building a very similar engine for myself. I've got two heads for it, a big valve hydraulic and a big valve solid. The hydraulic head has cams very similar to above, which I'll use to run it in until I get the bigger solid head finished. You didn't mention what piston/CR you're using? Mine uses the Wiseco forged pistons and is 11.8:1. I'm keen as mustard to finish it and compare the results.

[petert 583]

I've just been having a good look at the trumpet comparison. It's interesting comparing the AFR plots with the dips and troughs in the power and torque plots. A bit of time cleaning it up might improve things further.

[Robsbc 0 1 Cars]

I've just been having a good look at the trumpet comparison. It's interesting comparing the AFR plots with the dips and troughs in the power and torque plots. A bit of time cleaning it up might improve things further.

 

Trev is running standard pistons...Compression is higher as head was machined last time and maybe this time round too.

 

Regarding the trumpets graph Dave Walker @ Emerald had initially started a bit of mapping on the 75mm and then did a power run and moved over to 40's. Dave just wanted to compare the dips before he went on and finished the whole map. As Trev decided on 40's DW had to start again...

 

Also at Emerald a 306 S16 on tb's only and rear exhaust system made 190BHP & 158lbft.

Edited February 22, 2006 by Robsbc

[Revla 2]

Well done trev, f***ing brilliant result!! I better get mine some bodies now and get some proper power out of it......

 

Whats does it drive like??? Is it still quite powerband'y or is it smooth power right through the rev range? Does it feel a lot quicker than when you took me out in it?

 

Maxi

 

Jamming mate! I'm well pleased....

 

Under about 3.5-4k its nice for town driving, after that a band comes in, then another pull after somewhere

around 6k ish.

 

Yes, it is quicker than when you went in it, was running way rich.

 

Trev

 

 

I've just been having a good look at the trumpet comparison. It's interesting comparing the AFR plots with the dips and troughs in the power and torque plots. A bit of time cleaning it up might improve things further.

 

Hi,

 

What do you mean by cleaning up - matching inlet manifold to ports or?

 

Cheers

 

Trev

[petert 583]

What do you mean by cleaning up - matching inlet manifold to ports or?

 

If you look at the 75mm trumpet AFR, it looks like a double camel's back from 5000 onwards. Some fine tuning of the mixtures may have flattened/improved the power/torque curves. It's even more interesting that at around 5700 the mixtures approach 13:1, yet the torque curve dips down, suggesting it may have liked to be closer to 14:1 at this point.

[Revla 2]

If you look at the 75mm trumpet AFR, it looks like a double camel's back from 5000 onwards. Some fine tuning of the mixtures may have flattened/improved the power/torque curves. It's even more interesting that at around 5700 the mixtures approach 13:1, yet the torque curve dips down, suggesting it may have liked to be closer to 14:1 at this point.

 

Dave just did a 'quick' map to look at the differences between the 40's and the 75's, then I decided, with

help from Dave and RobSBC on their views of the best to go for.

 

I could always try the 75's on a full map at a later date..... Money availability!