ITBs + short trumpets = worthy? - Saxperience

Igorbio · 16th April 2012, 08:12

Hello!

Read a lot about ITBs here.

Thinking about IBTs, but not going to cut the scuff panel - so shortest trumpets are my only option.

As long as I understand, they don't give that much gain in the lower end (need longer ones here), but are throttle response and high end torque noticeable?

PS road and track use with 708 (and a like) cams

willsy · 16th April 2012, 09:13

Are you literally just wanting to fit the throttle bodies to an engine that is already using 708 cams?

Will you be fitting forged pistons or just keeping a pretty standard bottom end?

I fitted TBs on my old Saxo. The engine before had 708 cams, had been rebuilt and had a bit of headwork. The TBs were fitted afterwards.

Honestly without spending the extra on the internals the difference of just TBs alone made virtually no difference. On the same set of rollers I gained 1bhp and the general graph curve was very minimal.

I still regard fitting TBs as the biggest waste of money that I spent on the Saxo. For the amount it cost it was not worth it atall.

From my experience I'd say don't bother unless you are going to spend extra to fit forged pistons, tinker a bit more with the engine itself to really make the most of the TBs

They are good provided that you've got a suitable engine to compliment them

Igorbio · 16th April 2012, 09:22

My plans are as follow:
1. Fit predator ECU, map it to suit decat setup
2. Cams (708 or something like that) + probably some headwork + remap
3. ITBs + remap

You mention forged pistons - I thought they are only for really wild setups, really extreme NA and turbo/super-chargers...
What is the need in them on road running cams?

Quote:

Originally Posted by willsy

Are you literally just wanting to fit the throttle bodies to an engine that is already using 708 cams?

Will you be fitting forged pistons or just keeping a pretty standard bottom end?

I fitted TBs on my old Saxo. The engine before had 708 cams, had been rebuilt and had a bit of headwork. The TBs were fitted afterwards.

Honestly without spending the extra on the internals the difference of just TBs alone made virtually no difference. On the same set of rollers I gained 1bhp and the general graph curve was very minimal.

I still regard fitting TBs as the biggest waste of money that I spent on the Saxo. For the amount it cost it was not worth it atall.

From my experience I'd say don't bother unless you are going to spend extra to fit forged pistons, tinker a bit more with the engine itself to really make the most of the TBs

They are good provided that you've got a suitable engine to compliment them

willsy · 16th April 2012, 11:01

To make the best of the TBs the best results seem to come from a forged engine with some more lairy cams.

Have a look at AlexB's spec or ask jpsaxo about his build that Sandy is doing for him. Theres alot of work gone/going into those engines which really makes best use out of the TBs and they are beneficial. Granted there's alot more money going into the build.

For a relatively standard engine in reality that has 708s or equivalent it is really still a mild setup. When I had my throttle bodies fitted and Omex fitted/mapped it cost just over £2k on the invoice. General driving was barely any difference and RR figures were lame.

Bang for buck on the engine which I had was awful, I'd never have TBs again nor would I recommend them unless you really want to put the extra money and effort into the engine itself to do them justice.

Igorbio · 16th April 2012, 11:45

hmmm... seems like it`s better to save money for tires and skill improvement instead of ITBs on mild setup

AXracing · 16th April 2012, 13:52

GMC used to sell long trumpets with a upward bend in and a low profile air box that would fit in the stocks shell and worked really well.

Beaniemoo · 16th April 2012, 14:54

I managed to run 90mm trumpets without cutting the bulkhead!?

Igorbio · 17th April 2012, 07:35

Quote:

Originally Posted by Beaniemoo

I managed to run 90mm trumpets without cutting the bulkhead!?

sure you did, but:
1. Air filter won`t fit
2. Are those trumpets too close to the panel - is that ok?

axsaxoman · 17th April 2012, 08:23

no tumpets are too close to panel for best results
708 cams are mild and can run on single t/b ,if you are wanting t/b,s that can run a filter unit and are simple to fit see ours
http://www.gmcmotorsport.co.uk/engin.../prod_573.html
you can run an ITG type foam unit on these and you need no other parts of any sort to fit thses to yuor car