Can you close the GT4Series III vs Series I HP gap thru tuning and cat removal?

OK Techies out there. Alot of discussion in other threads about Series I pre-mid '75 HP at 255, Series II @ 240 and Series III with full emissions at 205. Can you tune away this gap by removing the cats, and tuning the engine/carbs to Euro specs? If now all the way, how much do you think you might recover? Enough for it not to be noticeable? Please be specific about what steps could be taken with minimal/reasonable cost.

 

HaHaHaHaHa.

 

The biggest difference is the camshafts. So to answer your question; no it can't be done with minimal cost.

Then you have to deal with the weight differences between Series 1, 2 , & 3.

And on and on.

If you want the bigger hp the only way is to buy a series 1 car.

Sorry for the bad news.

 

you won't get to 255, but you can make a difference without spending $$$ with an exhaust and by re-jetting the carbs. IIRC, Bernardo had his '79 re-jetted; not sure how much else was involved, tho. try a pm.

 

1. Camshafts are the big difference (prob about $1000)

2. Putting on a dual free flow exhaust will help a bit, especially if you have a thermal reactor, with a pretty nice one made for $600 using Magnaflow silencers and Ansa tips at your local race shop.

3. You will also feel a bit of difference simply by simply going to 140 main jets in the carbs ($50 + 1 hour), especially in a 79 with original 125 mains.

4. Although contentious, you will get a few ponies with a free flow air filter ($30)

OBTW, in reality few if any Series 1 really made all of 255 hp out of the box...

If you go to FChat sponsor Carobu's site, they dyno a 308 gt/4 Euro engine squeezed for all its worth...

If on a budget (like me), I'd recommend 2 - 4 now and save up for cams for the next belt change.

 

I'd be interested to hear what the results were from anyone who has actually done these things to a Series II/III...

 

Not trying to be smart at all but am I missing a good source for parts? If you know where to get a new set for a grand please tell me.

Just for fun I thought I'd see what I could buy a set of camshafts for.
$1,000 wouldn't even get me 1/3 of the way to a set of shafts.

 

you might be able to regrind the original camshafts for about $1K. think there was a thread about this a while back, a mondial was the subject car.

john

 

You can get them re-ground for about $1000 - $2000. Recommend WEBCam.

 

Back to what I said at first....

No, it can't be done at minimal cost.
Sell the series 2 or 3 car and pony up the cash for a series 1 car if you really want the hp.

 

I'm sure there are loads of threads about this already on how streetable they are, but if one is going to go through the trouble of replacing cams, why not go all the way and drop in a set of P-6's?

Last time I checked, these cams were the least expensive out of all the 308 carb cams available at F of UK Classic Parts. Least expensive is a relative term as they were just under £500 each cam.

Off-topic here, just how streetable are these things and can they be used with an aftermarket F.I. system? I had heard that they are quite "pulse'y" at idle (and this may disrupt vacuum signals that the ECU needs to adjust mixture at idle).

 

My first car came to me with P-6 cams, 9.7 Borgo "GT/4 LM" pistons, two of which were burned. Number 8 was DOA, zero compression, zero leakdown. Number 7 was losing almost 40% on leakdown.

How did it run? How would any V-8 run on 6 1/2 cylinders? Actually, it ran very well. It idled down pretty good and remained smooth. No thumping or huffing. 900 RPM was easy, although it did want to die when you brought it down fast from speed.

I have toyed with the idea of putting them in the other car, but as it only has 8.8 compression I just dont know if it would be worth it. Might be nice to do back to back runs on a dyno though eh?