2 valve GTSi, performance upgrades?

My old GTSi had a custom exhaust from Magnaflow. I still couldn't outrun a remotely sporty modern car in a straight-line race, but it sounded unbelievable, and felt reasonably quick (in no small part because of the sound and the lowness to the ground).

 

Unfortunately, no.

You can change the sound but that's it. Nothing "bolt on" will change a thing to make it faster.

 

Not much other than removing all the emissions junk and trying to lighten everywhere possible. BTW, I have the weights of many of the bigger items.

I have a QV and I'm looking into buying a 328 engine to swap in and then add ITB's or Webers as seen in the Mondial HotRod thread. If you are looking for sound, plus it looks gorgeous, that's the route to go. I'd love to do a 3.5 liter with the 360 crank but it's hard to justify that cost.

edit...

Go to the 308 technical sticky section at the top and look for the The SNJ5 hyper-Mondial threads section towards the bottom.

 

No drawback other than emission test issues and resale problems to anyone in a state that tests.

Your car's actual hp is closer to 180 and that is a tough hole to climb out of simply by changing the muffler and a few parts upstream from it. Any gains are going to mostly be placebo.

Your model year is actually my favorite. Slower but I love the simplicity of the aesthetics.

 

Yes. The difference when I installed a proper exhaust was definitely noticeable.

 

How much of the exhaust did you change? I have mostly been under the impression that the factory headers were not too bad

 

The only good way to upgrade performances without seeing anything from the outside, is very expensive: you have to bore the cylinders barrels and change the pistons with state of the art forged ones. I suggest you the CPS, they wrek great, tested on several cars. You will have a bit bigger displacement (40 cm3 more or less) a bit higher compression ratio and much more power due to much less drag of the new pistons. 20 k with valves too (more or less: maybe much less, here is 10-12 K).

Please check the actual compression ratio and see what it is: Often owners says the car is not enough fast just because the engine has no more the performances it had when new

Ciao

 

Removing smog equipment won't make much difference.

Probably the easiest way to get some real HP gain, would be to bolt on a supercharger. This could always be removed later. The stock CIS fuel injection system can easily supply enough extra fuel.

https://928motorsports.com/parts/ferrarisupercharger308-328.php

 

maybe better selling the car and buying a QV or, even much better, a 328.

ciao

 

This will give you the best bang for buck..
Removing the CIS injection system and fitting individual throttle bodies with say a motec system would be the next best thing..

 

I did carbs with high compression piston, bigger intake valves plus some more uprades...

= 264 horsepower dyno tested

Now its really fun to drive it and it really feels like a Ferrari;-)

 

I'm sorry, but there isn't any possibility, or at least there isn't one cheap, quick and bolt on.

It's not much fast even the euro version, without all the antipollution systems. In any case I'm sure it's a great car also as is.

Ciao

 

easiest thing you can do is change the two us digiplex boxes for european equivalents -
plug & play ... and available new at Maranello Concessionaires in GB


to even expand on the ignition theme ... the best thing you can do is
install the xdi-direct-coil-ignition from NicksForza - best bang for the buck

the mod will not change power or speed but the ignition timing
and what you will feel - seat of the pants - is ... torque !

it really awakens the 2Vi

 

These cars aren't really that much faster. The 3 liter engine is just too small, compared to a 7 liter Corvette, or 8 liter Viper. Supercharging/Turbocharging is the way to go. F40 would not be very exciting without the turbos.

 

Agree. It is plug and play and can be done with the euro boxes for near neutral money once you sell your originals. Does enhance the drive-ability of the car.

 

John,

The comments on early 2V cams (NON CAT) and pistons, but then you are almost forced to do the engineering the Factory avoided, to retain the CATS.

No one can tell you to take those off and in fact modern hi flow units do not have much if any performance penalty.


You could bore it out to 4 Liter, that gets you new pistons!

 

Forced induction is the ONLY way to go unless someone wants to spend MAJOR money increasing the displacement.
Exhaust upgrades, smog removal, ITB's, Ignition upgrades, digiplex upgrades, etc. will do next to nothing.
People get hopeful and hypnotize themselves into believing that their car is faster after such changes but they are kidding themselves.
If it were that easy, everyone would have done it by now.
DIY displacement increase - $14,000+
Qualified mechanic displacement increase - $30,000+
Turbo/Supercharger - Not sure but probably a good bit cheaper than displacement changes. Others on here are can chime in on the cost. Also, consider the side effects to the engine which isn't set up for forced induction. To do it properly, you probably need to change out a bunch of stuff (valve springs, etc.) that would add considerable cost.

Bottom line, you can't do **** without getting deep into your wallet.
I can speak from experience though...There is absolutely no comparison between a stock 308 and a properly quick 308....none.

 

Nobody puts a supercharger on a 250 GTO, a car that barely has the top power of a 328: so why you want to do it with a 308?



ciao

 

Nitro ? anyone have tried this ?

Guido

 

Nitro?

Do you mean:

A) Nitro Methane, or

B) Nitrous Oxide?

 

you can put in some race fuel: it's a beast, adds 4-5% top power (not bad). Elf has the excellent ELF ATMO RC

https://www.totalerg.it/pdf/ELF%20ATMO%20RC.pdf

ciao

 

Not sure if you are serious. It is insane to compare modifying a car worth 10's of millions of dollars to modifying a car worth 10's of thousands of dollars.