My speedster project

alanoo

And the reason why I guess it will be VERY noisy :shock:

:roll:
The manifold + cat looks really fine, but I don't like the silencer at all dunno..

Matt

That silencer is tiny! The rest looks superb though 😃

vocky

looks great, as long as it sounds ok then enjoy 🙂

Matt

Do you have any noise restrictions over in France?

Sjdickso

That looks very nice indeed, looking forward to a sound clip.

alanoo

vocky said:
looks great, as long as it sounds ok then enjoy 🙂

I don't care how it looks or how it sounds. It just has to make some good power figures 😃

Matt said:
Do you have any noise restrictions over in France?

Same as in the UK I guess
Theorical 95dB for most tracks but not always/often applied

vocky

well it looks like it will flow well, so hopefully the bhp figures will match

alanoo

Cam timing accuracy is the only possible issue left
Answer in a few days with the mapping...

alanoo

http://www.madac-sas.fr/articles/opelspeedster.htm

Ok so... basically I have a 2bular "Ultra" like silencer...

vocky

what a cool exhaust 8)

exmantaa

It looks cool, but I really don't like how they merged your primaries...

Normally this Y connection should be narrow so the passing exh. gasses create a suction effect in the other tube. But on yours they seem to have welded some bends together onto a straight pipe. Looks more that the gasses collide with each other there. Not good for ultimate power...

alanoo

Yep think the same...

I'll check on ours if it is really like that, and if it is the case I'll get it modified by our F1 exhaust welder

sdbutler10

that is such a nice system i hope u get some good results out of this wish i could get exhaust manifolds for my car that easy 🙁

alanoo

They are mapping it as I am writing this.
Unluckily enough it happens a day it is 35°C there so the ignition advances will certainly be a bit degraded and cost a few bhp

I hope they'll finish it this evening

vocky

any news ?

slimvince

any news? drool.gif

alanoo

Some good, some bad news...

First the bad ones :

the 4/2/1 manifold they made was put directly to the bin. It had many leaks and design faults. The manufacturer will do a completely new one restarting from scratch as soon as they come back from vacation... Unfortunately it is only early september...
So we had to put back the OE cast manifold + line with original cat (precat drilled) + their new silencer (55mm inside diameter)
Then the mapping, the rolling road and.... 180 bhp at _5700rpm.... 180 bhp at 6500 rpm.... 180 bhp at 7800 rpm, a perfectly flat power curve which shows a huge bottleneck

And the good ones :

180 bhp at 5700rpm is exactly what our model predicted, so once sorted, this should works fine
It is already much faster than other "mid" spec (remap + line) N/A which where on the same trackday as us today 😉

vocky

that is a shame 🙁

it looked good, but if it leaks, it's a nice ornament !

the power figure looks very promising, certainly the exhaust manifold will be reducing the engines flow, get some itb's on there too :lol:

alanoo

I think the stock manifold could flow a bit more than these 180bhp; our restriction maybe in the line diameter or even the catalyst which is in an unknown health.

But well, it was quite funny to see, the torque line dropping on a straight line (and not a curve) after 5500 rpm upto 7800 rpm 😃

Oh and another good news is that the engine survived the dyno at 7800 rpm 😉

markv

alanoo said:
I think the stock manifold could flow a bit more than these 180bhp; our restriction maybe in the line diameter or even the catalyst which is in an unknown health.

But well, it was quite funny to see, the torque line dropping on a straight line (and not a curve) after 5500 rpm upto 7800 rpm 😃

Oh and another good news is that the engine survived the dyno at 7800 rpm 😉

But you also had the original downpipe/cat in there? I think that would be more of a problem. Pipe diameter is just way too small. I agree that the manifold isn't very good, but the pipes are even worse! Think you made the perfect proof how important the pipe diameter actually is for this engine.

Mark

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