Engine tuning

[Megatron]

Been pondering on how to squeeze extra ponnies from the engine without actually turning up the boost. Met a mate of mine the other day and we got talking about what he had done to his car (J-Spec TT, 6-speed). He had the engine rebuilt with forged goodies (JUN parts mostly), Blitz FMIC, uprated Camshaft (272 inlet/exhaust), cam gears and valve springs etc ect. But he noted that uprating the camshafts/gears and valve springs alone netted him some 50 Bhp at the crank without upping the boost! (He had the car dynoed before and after he had em fitted)

So with what i have in mind, i reckon i should follow suit. I am not thinking of running silly horsepower figures ( I am aiming at 380 Bhp at the crank ), and would like to keep the car running on stock boost for as long as possible (to aid turbo longevity).

Another future mods iam contemplating would be to uprate to an FMIC. But i was told that this is not strictly necessary if iam not upping the boost or thinking of doing a single conversion and if the stock IC are still Ok.

Is this the best route?

[~Rob~]

The mian reason most people go for increased boost is the bang for buck! for a few hundred quid you can easily increase power by loosing the CATs and turning up the boost and keeping the charge temps as cool as possible. the parts for this simply bolt on, not requiring massive mechanical knowlege.

on the other hand, installation of parts such as cam gears, cams, valves, springs etc require much more mechanical knowelge as the head is being rebuilt.

tot'ing up the costs, option B would easily amout to a couple of grand before any labour was involved, where as a simple higher boosting, decatted option would probable stand about 600 quid. the power outcomes would probably be in the same region too.

i have boost at 1.05 bar with FMIC, decat and pannel filter in stock box. probably spent around 1000-1100quid and got quite a good crank BHP figure. i also now have room to play, as cams and gears would be a nice next step. whereas if you really wanted to keep stock boost, you would have many restrictive parts still on the car, capping your power figure.

You must also understand that getting more power out of an engine, my tuning parts, upping boost, bigger turbos etc. will put more strain on those parts. by not upping boost, you may be not straining the tubros, but you will be putting more strain on other parts, such as valves etc.

in answer to your question, i would say it is not the best route. in my own opinion of course

[chrisandrea]

thats a good hp figure rob, was looking at your baby, have upgraded to 5.1 brake fluid? if so how did you bleed the t/c and can you bleed the master cylinder?- also how did you get all the old fluid out of the whole system(esp t/c?)
I'm planning to book my baby into envy to get turbos hybrided in the spring, intrested to see how much hp i'll get then!

[Martin F]

Originally Posted by Megatron

He had the engine rebuilt with forged goodies (JUN parts mostly), Blitz FMIC, uprated Camshaft (272 inlet/exhaust), cam gears and valve springs etc ect. But he noted that uprating the camshafts/gears and valve springs alone netted him some 50 Bhp at the crank without upping the boost! (He had the car dynoed before and after he had em fitted)

I'm sorry but i'm going to raise the BS flag on this one.

Cams, will increase power output slightly but usually at the expense of low down torque. Cam gears have been known to not show great gains in power but mainly to move the torque peak left or right and valve springs will not have any effect on power (unless your old ones were totally knackered).

Yes he may have had before and after graphs, but i suspect there was some other factor(s) involved.

As Rob stated above, for return on investment increasing of the boost and opening up the breathing will win time and time again. Why would you not want to go down this path?

[Megatron]

Originally Posted by Martin F

I'm sorry but i'm going to raise the BS flag on this one.

Cams, will increase power output slightly but usually at the expense of low down torque. Cam gears have been known to not show great gains in power but mainly to move the torque peak left or right and valve springs will not have any effect on power (unless your old ones were totally knackered).

Yes he may have had before and after graphs, but i suspect there was some other factor(s) involved.

As Rob stated above, for return on investment increasing of the boost and opening up the breathing will win time and time again. Why would you not want to go down this path?

Well i had thought about upping the boost for sometime now. But living in a country where the average temperature is 36C cant be too good with the increased boost! I was advised to uprate the standard IC for a FMIC before going this route. But was put-off by the possible complexities involved (removing/replacing the tranny cooler/radiator etc etc and bearing in mind that where i live they deal mostly with J-Spec models) which may or may not involved hidden cost!

FYI my car is fully decatted

[Kev.O]

After reading this it got me wondering about cam gears. How could simply replacing a gear add bhp? Surely the teeth must be in the same position? http://www.mkiv.com/techarticles/cam...all/index.html

[Martin F]

Aftermarket cam gears allow you to position the teeth slightly advanced or retarded in relation to the position of the camshaft, so in effect you can advance or retard the point when the valves open. This can on some engines mean that you pick up horsepower as due to many factors the valves may not be opening in the most optimal position. But like most things on our engines Toyota done a pretty good job and on a stock engine these are not going to show much advantage.

If you have a medium\large single enlarged valves etc, then there may be a benefit, but that's a lot further on than BPU.

[Kev.O]

Thanks for answering my question Martin.

[~Rob~]

Originally Posted by Megatron

Well i had thought about upping the boost for sometime now. But living in a country where the average temperature is 36C cant be too good with the increased boost! I was advised to uprate the standard IC for a FMIC before going this route. But was put-off by the possible complexities involved (removing/replacing the tranny cooler/radiator etc etc and bearing in mind that where i live they deal mostly with J-Spec models) which may or may not involved hidden cost!

FYI my car is fully decatted

You should be seeing some increased boost already mate, with full decat. should be around 1 bar. 0.7-0.8 bar is stock.

you got a boost gauge?

[Megatron]

Originally Posted by ~Rob~

You should be seeing some increased boost already mate, with full decat. should be around 1 bar. 0.7-0.8 bar is stock.

you got a boost gauge?

Havent got one installed yet. Thought i'll do it when i add the BC. I had the car dynoed with full decat, max boost was slightly above 0.8!

Had a run-in with and a lil EVO MR Y'day. Bloke dropped a gear and before i knew it he was two car lengths ahead! Reckon an FMIC and a BC would do the trick tho