10 replies to this topic

[MRclubman1100cc]

hey everyone at the moment i am using the standard cast intake/exhaust manifold. but i want to get an alloy intake and a set of extractors.... how much HP and torque will i gain on my 1098....

need to no before i go out and buy
thax...Todd

[biggav]

hey everyone at the moment i am using the standard cast intake/exhaust manifold. but i want to get an alloy intake and a set of extractors.... how much HP and torque will i gain on my 1098....

need to no before i go out and buy
thax...Todd

Depends on several things... what HP and Torque do you have at the moment??
Firstly, the standard inlet and Exhaust combination is actually quite good.. if you are planning on changing them then there are quite a few options on what to replace them with. There are quite a few Alloy inlet manifolds, i have an MG metro one which ive polished out a bit but there are several different ones in circulation. then you either separate your existing inlet/exhaust cobination with a saw, or get a new exhaust manifold.. again, loads to choose from and you may consider changing the exhaust system if you are doing this. you could also change to a KN air filter at the same time....Once you've free'd up a bit of breathing room, the carb will need to be set up again and may require a different needle as your mixture will be way to lean.

Before you do any of that stuff, has you car been well serviced?? if not give it an oil and filter change, new Rotor arm, ht leads, check the spark plugs and replace if necessary and that will make a hell of a difference for starters.

I'd recommend investing in a book called "tuning the a-series engine" by David Vizard In the book, he compares all different types of carbs, air filters, inlet manifolds, exhausts and gives the answers to any question you will have about getting the best out of your car.

[MRclubman1100cc]

soz i should of mentioned this before... it is a fully rebuilt 1098, i have added a custom air box with k/n filter and 1.75'' exhaust system and has a 1.5'' H4 SU carby....... i need to get a needle but ill wait till i get the alloy intake and extractors..... just want to how much more HP and torque i will get if i use the alloy intake and extractors.... At the moment it is 48HP with 80 N·m... would i gain another 2HP with it

[MRclubman1100cc]

come on people need some replys plz. i need to no ASAP before i go and buy it....

Todd

[Jimmyarm]

When I added my alloy inlet and freeflow exhaust manifold (extractor), I went from about 47ish to about 53ish on the BHP side and I cant remember the starting torque but it went up to 63lb/ft. And its a 998

You should get at least another couple of BHP out of it but you really need to get it onto a RR to get the best

[Mini-Dave]

The theory goes, that above 15mph the air behind the engine is the same temp as the air infront of it!

however im pretty sure Vizard did extensive testing into this, and if you do it PROPERLY and put alot of work into it, then it can make a difference, ie, the intake must have the smallest amount of curves, and be very smooth, so the air doesnt slow down in the pipe.

Dave

[Jimmyarm]

I think you are talking about something different there dave

Something I didnt mention was that it moved the peak power up by about 400rpm. It also drives a lot better than it did

[MRclubman1100cc]

Nice fellas, so i should be able to notice the power increase or not? i would be happy if i get another 5/6 HP.....

[Richard]

sounds like it should help a fair bit might try this mod

[Jimmyarm]

It does make a difference, but more in the delivery of the power than the physical speed and grunt. Remember we are only talking a few BHP & lb/ft here, nothing earth shattering

Its a good start on the way to getting more power though, next up is head and cam change

[MRclubman1100cc]

Yes Jimmyarm head and cam change ill be doing as well, after i get the Alloy intake and extractors, im getting a swiftune SW5 cam and a 12g295 head..... hope to get about 59HP out of it and about 91lb/ft