Hello all,
Im in the final stages of finishing an a14turbo project (blow through) using
-a14 de-compressed with an o-ringed block
-a15 head
-webber 32/36 with rising rate fuel regulator
-rx7series3 turbo (about 1 kg/cm2 boost which is i think 1 bar)
-vl commodore fuel pump
-4.11:1 diff
its auto so its a bit gutless till about 1700rpm then at about 2500-3000rpm she goes hard...........any way when im driving and accelerating there is no problem but when im sitting on a constant speed eg. 90km/h because of the diff the revs are up and im partialy on boost for a fair bit of time some times it pops and sounds like it sort of back fires through the carb abit........... it seems that the air is heating up and causing it to run a bit lean and pop or something (still to confirm this) but i was wondering if this might be because I dont have an intercooler?????

Who here is running a cooler on ther a-series and and who here isnt and why or why not ?????????

thanks all

sounds like it's advancing too far and pre igniting, popping I always think of running rich but I'm not sure how true that is.

With all turbo cars I recommend an intercooler as the turbo GREATLY heats up incoming air. Check your dizzy is set right etc.

cheers
Damo

You definately want to get an intercooler...I don't know if thats whats causing your problem, but whether it fixes it or not, an intercooler is an awesome investment.
The only drawback, will be reduced throttle response, but if you keep your inlet pipes as short as possible and not get an oversized 'cooler, it shouldn't be too bad. Even a small factory one that you can pick up for 50-100 bucks will be worthwhile (I've got some RX7 ones that I'll let go if you want), and you can use a water spray system to help improve its efficiency.
Get one, it'll give you more power and might save your engine too

If you don't want to go the intercooler path, you can go Water injection. We have installed our kits on other supercharged cars running no intercoolers (and making 350rwkw) and they have worked brilliantly - allowing more timing, more boost and allowing the tuner to run the engine leaner without detonation.

Worth a look Full Throttle Performance

as a point of interest my brother and his friends have been fitting quite small factory intercoolers as top-mounts on their 3ltr turbo diesel surfs and been noticing great differences in power without any other modification or adjustment (very sluggish motor in standard form)

at the end of the day an intercooler allows you to run better timming a lot more safely

Have you checked your primary and secondry jet sizes ,check your timing it may need to be retarded .You may also find when you are crusing at 90 the secondry may not be opening and its running on the primaries only causing it to lean out on long cruises, maybe try to get the secondry to open earlier and play with the jet sizes may help cheers ........