Evening All.

Would be very interested in getting people opinions on my rolling road print outs that I got today.

Some info on the car…It’s a 1972 fitted with a Cossie YB that was rebuilt two years ago. It has a 4WD manifold and T34 Turbo with a .63 housing. It is fitted with a 2.5 inch straight through exhaust; maybe I should put a back box on it for some back pressure???

I have a large type RS500 (Cheap version) intercooler. I have checked all pipes and am happy that I do not have any boost leaks. I pressurised the system up to 1.2 bar and cannot find any noticeable leak.

I have fitted a Stg 3 MSD Chip. I am running a new Amal valve that was fitted with the standard 2mm insert in the R port.

I have been reading about adjusting boost by jetting the amal valve. Long story, but I drilled out the insert to 4mm and these are figures that the car is now producing. I have a -31 actuator set with 4mm pre-load as described.

We removed the insert in the R port for a test run and the boost spiked to 1.6 very quickly and the car made 296BHP…. The amal valve does click when I remove and re-connect the electrical connections to the valve…

The owner of the rolling road told me that his road reads pretty tight and if i brough this car to another rolling road, it would be possible that the car would read closer to 300BHP....

I am interested to know is the boost tailing off to quickly…Any advice would be great…

Driving the car now is mental, 2nd gear at 6,000RPM will light up the rear wheel while running 195/50R15 tyres…

Power & Torque Graph[img]

Power & Air/Fuel Ratio Graph


Power & Boost Graph

 

with a 2.5 inch exhaust you already have too much back pressure
put 1 mm restricter in the c port and put the restricter back in the c port and try that

 

Cheers for the reply. Am I correct in assuming that the total diameter of my newly restricted C port should only be 1mm...

 

the standard valve has a 2.5 mm restrictor in the c port and the r port
reducing the c port restrictor size is the way to go

 

listen too the tea master

you got any pics of the car?

 

u can use weber carb jets as your restictor and the evaluate your boost curve and adjust the r port size to suit
reducing the c port jet increases boost enlarging the c port jet reduces boost
reducing the r port jet reduces boost increasing the r port jet increases boost
the larger the r port jet tends to increase the over boost spike
I would suggest a 1mm c port jet and a 3.2mm r port jet
if your after 2 bar you will need a -34 for this turbo

 

Guys,

Thanks a million for the feedback, this is exactly what i was looking for...Really appreciate it...

By doing as you suggest, '1mm c port jet and a 3.2mm r port jet'... What boost should I be expecting to see as a peak boost figure and then as a held boost...

I'm completely new to Turbo's, so just learning my way...My car was previously a 1.6 Xflow before i swopped in a 24V Cosworth BOA before the latest Cossie YB Swop....

Some pics of the outside, will stick a few of the engine bay as well



Some pics of me just having some fun in it....



First Day with YB running approx 240BHP while i getting to grips with Turbo Power..

 

On the rollers yesterday...

 

Wow that is stunning! Got a yb turbo capri myself.

 

Cheers Man...

 

Sweet capri

 

the amount of boost you get will depend on a number of factors here's just a few of the basics
actuator type ie spring pressure
actuator preload
the amal valve itself
the basic boost table in the ecu
easiest thing for you to do is jet it as specified and test the boost curve
absolutely loving the look of your capri
some very good pics indeed

 

Cheers for all your advice...

Will certainly jet the amal valve and let you know how i get on. Thanks for the comments on the Capri as well...

 

Cracking picture

 

i never liked capri's. i think iv'e just changed my mind. stunning car

 

I like the older capris. Never been to fussed on the last shape capri

 

Turbosystems - are these Amal valve restrictor sizes valid for stage 1 trying to run approx 15 pounds. If not what sizes would you recomend. Trying not to overshoot too much as triggers overboost cut. Thanks David

 

Liking that A LOT!

 

not suitable for a stage 1
but you shouldn't have a boost cut on a stage 1

 

Tone how should a stage 3 cosworth be jetted as mine doesnt have any jets in it

 

you should at least have the std jet in the c port

 

ah bugger shall I put 1 in then mate

 

yes as having an open c port will reduce boost

 

Ahh thats why it never hits 24psi then I have never had full boost no matter where the act is lol I have changed the turbo twice and 3 actuators lol

 

you have to love DIY certainly makes it more expensive

 

oops lol

 

 

Tone I have a old amal here with a restrictor in the r port can I take it out and put it in my C port then

 

you can take it out and stick it your japs eye if you like
the std cossie amal restrictors c an r are identical

 

+1! Mega

 

Cheers again for the help and comments....

Delighted with that picture....

 

i have had 333,344,347 bhp all on greens with an msd chip on 3 different cars. so with a little more tweaking im sure you will be near that.
cracking pics see it featured in one of the mags

 

cracking car is it a RS 3.1 or have you just flared the arches ?

p.s. put the silver wheels back on they look so much better than the orange ones.

 

Fantastic car i love the stationary pic on track. Must of sounded awsome with BOA in it too

 

The advice tony has given is good and once you get the boost where you want it it will use some of that fuel up as its getting a bit rich after the peak power on that chart..

If the afrs are still like that id suggest getting the fueling and ignition checked as theres more to come from it depending how the afr is once boost is sorted

 

Hi Guys,

Thanks Again, a quick few replys. This was a bog standard 1.6Xflow Capri. To allow me to run bigger wheels, i grafted on a set of Mk3 Arch's to the Capri.

Agree on the orange wheels, just threw these on while the silver wheels are getting some new boots....

Getting a 1mm jet for the C Port & a 3.2mm jet for the R Port turned on a lathe today, so will try and get back to the rollers with these soon.

Am going to do another pressure test tonight, this time upto 2 bar to see have I any leaks... Once i have filled the system to 2bar, how long should it hold that pressure for????

Costina, for Info, I would be very interested to know what size jets you have in your amal valve plus how much pre-load on actuator you have???

How much boost are you peaking too and holding to generate these numbers... That is the sort i power i want, just need some tweeking to get there...

Thanks Guys...

 

ROFL.........

 

-31 half hole preload std jet in c port nothing in return..

You really need it to hold 22psi and spike around 26 psi but please be warned as Tony as said there are many factors involed and you really need a wide band afr gauge to check to be safe.

344 bhp was on a std engine escos with a T34/63
347 bhp was on a std engine using a T34/48 (on the limit of injectors)
333 bhp on my std 110k engine T34/48

All dyno'ed on the same rolling road(flywheel figures)

 

Evening All, just looking back at this post, being doing some DIY around the house, so the Capri has seen very little TLC lately....

Been thining of upgrading the radiator to a 60mm Airtec unit to help with cooling on the track, unsure whether a 60mm or 70mm Airtect intercooler would be best for a stage 3 set up...

 

Just found this pic of me at a Recent Drift & Grip Day, not bad for 270 BHP....