Blend or trumpets

[jojackson4]

So what do you recommend for a 500 running STD ecu

Thanks, Peter

[MPoxon]

I went for the ACT Carbon Fibre trumpets on my 500 and was very pleased with the results.
http://www.actproducts.co.uk/shop/ti021-trumpet-se...

I understand the blended base versions you lose midrange torque but gain a fair bit of high end BHP. The ACT ones you gain BHP and Torque around 10 of each iirc.

[450Nick]

Trumpets.

http://www.pistonheads.com/gassing/topic.asp?t=132...

Edited by 450Nick on Monday 17th February 02:36

[900T-R]

Tried both (trying to substitute money I didn't have with 8 hours of Dremeling at first) - no contest, trumpets are the answer.

[Pupp]

Trumpets here and happy with them but Jools has been getting good results recently with the billet replacement 'blended' base he has developed - well worth investigating

[jojackson4]

A phone call to tim then
Thanks gents

[rigga]

My jools blended base certainly doesn't feel lacking, no numbers to back that up though, jools did post a dyno graph a while back showing it compared favourably to trumpets.

[Podie]

Also have a Joolz blended trumpet base on the Griff. Higher deck height than previous offerings, so no issues lower down the rev range. I'm certainly happy with the numbers and driveability.

[rigga]

Topic here with the graph that jools posted.

http://www.pistonheads.com/gassing/topic.asp?h=28&...

[900T-R]

Um, 38 mm manifold & trumpets vs. 45 mm manifold & blended base... no wonder the latter comes out on top. A 38 - 38 mm or 45 - 45 mm comparo between the two would be more helpful (and the only one of that sort I know about was of the 45 mm carbon trumpets vs. the Taraka blended base version, not Jools')

[spend]

A properly worked blended base gives you the opportunity to flow the inlet manifold which is where most of the restriction is. This goes into subtly changing entry angles to make the most of the pair when joined. Just opening the throats is only half the story, as they immediately turn beyond that & you can start to straighten them out with careful blending.

Don't be fooled into thinking you can blend a base with a dremel, you really need to weld up the base first where you will be grinding and have quite powerful die grinders. I would also always advise grinding the base joined to the inlet manifold so you can work out how to blend them together, that intimate experience is probably the only way you can see what is possible. It is very easy to open ports, the main problem is trying to keep them balanced due to the way the crossover occurs on the outer ports.

IMHO the inlet manifold far more restrictive compared to the trumpet base and blending gives you far more scope to address that which trumpets & circular patterns don't help you with at all really apart from adding a few mm at the top. Creating a base to enter the manifold at slightly more obtuse angles actually allows you greater access into the manifold, which as well as giving better flow lets you work deeper into the manifold a win/win situation.

[rigga]

Jools base is not a reworked standard item I believe, new casting and machined as required, stand to be corrected on that though.

Doh....looking at the two pics below its obviously a new completely different casting.

Edited by rigga on Monday 17th February 11:15

Edited by rigga on Monday 17th February 11:15

[Chuffmeister]

As per the thread 450Nick posted. I did mine for £60 with a die grinder and a couple of tungsten carbide bits. Great feeling of satisfaction. You can get the trumpets from Spencer Ashley at the link below. As for blended bases, there was a really nice bespoke blended base posted by Spitfire4V8 (see below). I think it was circa £200+ for the blended base (looks a work of art though!).

http://stores.spencerashley.com/rover-v8-48mm-upgr...

Spencer Ashley Trumpets


Blended based (see Spitfire4V8)

[rigga]

^^^^^ yup, that's the jools blended base I have.

[Podie]

Yep, that's the one from Joolz. CNC machined from billet aluminium.

Circa £230 + P&P, IIRC.

[swallet]

So for my currently standard 500 (except AFM-plenum elbow) is just wacking on some carbon trumpets or a blended base going to make much difference?


Do I need to get the inlet manifold ported as well - if this is the case then surely this also needs porting up to the heads?


It's an expensive spiral!

[swallet]

So for my currently standard 500 (except AFM-plenum elbow) is just wacking on some carbon trumpets or a blended base going to make much difference?


Do I need to get the inlet manifold ported as well - if this is the case then surely this also needs porting up to the heads?


It's an expensive spiral!

[rigga]

swallet said:

It's an expensive spiral!

Yes do you really wanna start should be your first question.

[jojackson4]

spend said:

A properly worked blended base gives you the opportunity to flow the inlet manifold which is where most of the restriction is. This goes into subtly changing entry angles to make the most of the pair when joined. Just opening the throats is only half the story, as they immediately turn beyond that & you can start to straighten them out with careful blending.

Don't be fooled into thinking you can blend a base with a dremel, you really need to weld up the base first where you will be grinding and have quite powerful die grinders. I would also always advise grinding the base joined to the inlet manifold so you can work out how to blend them together, that intimate experience is probably the only way you can see what is possible. It is very easy to open ports, the main problem is trying to keep them balanced due to the way the crossover occurs on the outer ports.

IMHO the inlet manifold far more restrictive compared to the trumpet base and blending gives you far more scope to address that which trumpets & circular patterns don't help you with at all really apart from adding a few mm at the top. Creating a base to enter the manifold at slightly more obtuse angles actually allows you greater access into the manifold, which as well as giving better flow lets you work deeper into the manifold a win/win situation.

Do we have any names for the work above and ball park prices
As I'm trying to get the top end sorted either trumpits or the blended before I go after market ecu
Just trying to spread the out lay

Sorting the manifold looks like it neads doing wich ever way I go
Thanks for the replies gents

[450Nick]

swallet said:

So for my currently standard 500 (except AFM-plenum elbow) is just wacking on some carbon trumpets or a blended base going to make much difference?


Do I need to get the inlet manifold ported as well - if this is the case then surely this also needs porting up to the heads?


It's an expensive spiral!

To remove the bottleneck all the way through, yes you would need to go right down to the valves. The trumpets however will give you a fair gain (can't remember off hand, but speak to Tim for exact numbers). The improvement on pulse wave tuning will have an effect on power, independent of a bottleneck caused by a restrictive inlet tract. If you see my link above, it goes into the reasons behind this.

As I also say in the link above, going with a blended base means that you are changing your primary inlet runners to unequal length, as the 4 centre cylinders have a shorter tract in the inlet manifold, and this difference is usually countered by having the central 4 trumpets longer than the outer 4. This will not help your pulse wave tuning, and I would think contributes to the fact you lose a fair amount of mid-range when going with a blended base. Since torque is the bit that you feel when you put your foot down, torque is what you should be aiming for.