SR with T40's - power gain?

[Stanley]

if i stuck a set of T40's on an SR engine what would i expect to gain from it?

would be a straight thru exhaust too.

jst planning while i have the engine sitting

cheers all

[paul james]

about 20 bhp. I would put a performance cam in too, then have it all set up properly, then you should be reaching 100 bhp

[Stuart]

id say on a std engine ... 10bhp.
add a 285 kent cam and an SRI head youd be looking at about 105ish bhp

[Adam]

id say on a std engine ... 10bhp.

Thats exactly what i was going to say, on a std engine the gain aint that much, but with other things, cam etc, the gain is a lot better.

[womble sri]

well my sr was 90bhp with a pair of twin 40's and exhaust system. which aint fast so id wait and get a cam

[mad-driver]

I'm about to put 40s on mine, as i have the carbs, just need to sort a few things out and get a 1200/1300 head to match, then at a later date put a decent cam in it

[SRlew]

yer im just going to wait now and get cam and modded head aswell before i put some on.

[GregMeaker]

I got a 1.4sr. I put my 40's on,kent cams,straight through magnex and flowed,ported and polished head. it was rolling roaded at 110bhp. its not just the horse power though, it influences torque alot and makes the car pull alot better in higher gears. And the sound :-) hope that helps.

[mad-driver]

And the sound :-)

lol thats mostly the reason i have them:D

[womble sri]

i had mine set up last week cam, worked big valve head and a pulley, new jets ect in carbs and it put out 125bhp a lot of people on here say mateys rollers are out but its well fast.

[mad-driver]

it will feel quick, but 125bhp seems a tad optimistic, my car feels quick for what it is, and thats probably running around 85 at the minute

[womble sri]

yeah i agree 125 is a bit high but it is a lairy cam. before my car was cammed ect it was 89bhp but it will of defenitley lost power. it wasnt really quick at all my sri was probably faster. all my friends cars were faster i.e new civic 1.6 vtec escort gti and cars like saxo westcoasts were pretty much even :mad:. but now i **** on them all and that was before it was set up lol one of my mates has a pretty **** rs fesi and i wouldnt mine having a go at him cos the acceleration on my novan is immennse and it just puills to about 115 in 4th gear easy depending on the accuracy of the speedo prob about 95

[mad-driver]

I whooped an Escort GTI in my car, so just shows they're crap anyway lol

[JAMIEP]

Gettin twin 40s soon 2 put on my 1.4spi, nd an sri head...is it worth getin a manifold??

[Snowface]

without it ur engine won't run so i guess so.

[SRlew]

ahh your making me want some right now!!

[womble sri]

do you mean inlet or exhaust manifold you will need inlet there is one on ebay at the mo in good cheap too i was kickin myself cos mine was 130 from online autosport i havent got an exhaust manifold but am going to get one will be well worth it

[CP]

A word of warning:

Tuning old worn engines is ultimately disappointing. Make sure before you attempt to do a lot more than a filter or exhaust change that your engine is healthy - ie do a compression test.

Adding a set of T40's as you describe is popular but is really putting the cart before the horse in many ways. The performance potential from them is enormous no doubt - they are easily worth over 150hp but NOT without a radical change throughout other important areas in the engine. If you aren't going to increase valve sizes, port out the head, put in a long duration cam etc etc them why spend so much money? For lesser states of tune a weber 32/34 DMTR/DMTL will suffice - the money saved could go to a cam or a better head. Plus you can get other lower cost signficant performance changes such as adding a good octane booster to your fuel and getting the timing set right at a rolling road.

[JAMIEP]

yeh soz i meant exhaust manifold, is it worth gettin and what kinda power gains if any?? cheers

[Mark T]

Yes a 4 branch manifold would make a nice difference.. I'd listen to CP thongh.

[womble sri]

yeah get an exhaust manifold but as cp says bolting carbs on will not give much of a gain wait and get a cam and some headwork then you wont need to get the carbs set up twice.

[mad-driver]

Very true, i think an example of this is Keith's Nova, a fully built and setup engine made 119bhp i think, which is very good for a 1.3. However when that engine went pop, for one reason or another, a replacement engine consisting of Twin 40s and an exhaust system made only 84bhp, so its quite clear that the headwork and cam is benefitial;)

[JAMIEP]

Wud a cam of a gte engine b any good cos my mates puttin a kent cam on his?? jus wondering cos i cud prob av it for cheap!

[womble sri]

maybe but its not worth it still not that much of a gain wait get a proper cam kit, pulley and sri head

[krobinson]

Very true, i think an example of this is Keith's Nova, a fully built and setup engine made 119bhp i think, which is very good for a 1.3. However when that engine went pop, for one reason or another, a replacement engine consisting of Twin 40s and an exhaust system made only 84bhp, so its quite clear that the headwork and cam is benefitial;)

And that spare engine with 84bhp was a total disapointment. You definatly need the head, cam, and a rebuild bottom end to get good power!

I'll be trying 32mm chokes to see if we can squeeze some extra bhp out of mine, but i think 119 is the limit without going for a AST18 or 19 cam, but that would just affect driveability too much.

Keith

[mad-driver]

Wud a cam of a gte engine b any good cos my mates puttin a kent cam on his?? jus wondering cos i cud prob av it for cheap!

The 1400 SR cam has more lift than a GTE cam, i changed mine to GTE but was told to put mine back on as it was better

[Stuart]

JamieP i reffer you to Dans announcement at the top of every forum.....