85WHITEZ51

With all this talk about SR and MR it makes me wonder which is faster in the 1\4 mile. At the track it seems to me that the LT1 is faster in the quarter as they usually have lower ET's. If this is true then why do people say that a MR auto will be slower than a mod. TPI auto car. My GF dad's 94 hangs prett well with my 85 off the line but I usually get ahead of him from the line to about 1\8 mile and then he starts to catch up. For reference his car is stock down to the paper filter and my car has the mods listed below. His car has 88K on it and mine has 155K. Just seems to me that if the torque suffers so bad on a MR car it would to sufer on a LT1 thus me being farther ahead off the line. We both have autos and 3.07 gears. Please infor me.

vader86

how is a miniram auto gonna be slower than a ported out TPI auto? who said so? Maybe if someone cant drive or hasnt tuned his MR setup correctly. MR really needs a six speed so you can put lower gears in it to offset the low-end torque loss, but if the guy knows how to launch it still isnt a problem.

Only reason that 94 might not be holding up with you is his gears or his launch technique. (not too different for A4's but there are little things that you can change to get better 60ft) LT1 autos need at least 3.54-3.73, then he's gonna beat you if he can launch it.

GlockLT4

Engine for engine.. the LT1 will always win (stock). L98's run out of breath as everyone here with an L98 will tell you. If you're comparing 2.59's to 4.10 or something, that's another obvious conclusion. An L98 with gears and an LT1 without gears .. the L98 might be able to get him on the ET. Probably not the MPH though.


[Modified by Glock'94, 11:12 PM 5/8/2002]

Mr Mojo

Car on the left(4477) is me in my '95 LT1, the car on the left is a '88 L98, mine is completely stock, the L98 has a few tuning tweaks but otherwise stock.

GlockLT4

Good temp for racing :yesnod:

Fastguy

Well, with DR's, 2,600 stall, headers/duals, free mods and practice, I ran 13.2@101 tonight. A black bone stock 95 LT1 was running 13.1-13.2@108 tonight. With a good driver, a stock LT1 will see low 13's regularly, an L98 in total stock configuration just plain won't.




[Modified by Fastguy, 12:44 AM 5/9/2002]

Rob 93ZR-1

12 second club is so :cool: As soon as I decide to bail out of my stock SCCA class, I hope to join you there. :cool:

85WHITEZ51

I think my point has been missed. You show how a LT-1 is faster than a L-98 in the 1\4 mile and it has basically a factory MR. So why does everyone say that you will lose so much torque with a MR over TPI system. I am just trying to figure things out. I want a MR but I have read on the forum that if you get one you will lose alot of torque and it will make your car slower than it was before in short races like 1\8 mile and 1\4 mile.

vader86

WHY: the runners on the TPI are like 20in or so long, resulting in huge amounts of torque, the runners on an MR are like an inch. This is why the TPI runs out of breath at high rpm-it cant feed the air in quick enough. This is why the MR can run high rpm. It wont make your car slower, that wouldnt make sense. You just will lose some torque low in the band, and you may not notice it at all. The MR raises the torque higher in the band as to give more hp numbers.

65Z01

Pleeeese Frank, we both have some mods. You were then building more than 300hp as I was less than that but more than the stock L98s 240hp, look at those trap speeds.

A true test would be my current L98, with nearly 300hp at the crank, against a bone stock LT1, with 300hp at the crank, and the same gears and A4.

It's realy the extra 50-60hp, bone stock, that makes the LT1 the winner, by about 1/2sec (compare your new '95s mid to hi 13s with my baseline runs of 14s flat).

Nathan Plemons

I believe you'll find that the L98 torque advantage is largely exagerated. Let's see them, BONE STOCK L98 dyno numbers. Just a very quick glance that the performance registry shows me the first two STOCK L98's I found made 315 torque and 320 torque.

I'll use Scorp's as an example



Notice how quickly it peaks and makes that power, but after 3000 it's all downhill from there, by 4500 it's pointless to stay in that gear.

Now here's my stock dyno graph



Now notice it's doesn't peak as high as Scorp's but it doesn't peak at all really. The L98 in this case makes 300 at 2000 rpm's, makes it all the way up to 315 at 3000 and then falls back to 300 at 3500 and falls fast from there. So the L98 "torque monster" makes a peak of 20 more pounds of torque for all of 1500 rpm's. Meanwhile the LT1 continues to make the same amount of torque all the way up to around 4300 where it starts to fall, but even then it's a slower fall which still allows HP to build as the drop in torque doesn't "outrun" the rise in RPM.

That's why the LT1 will win plain and simple. Now an L98 with a MiniRam like you say is VERY similar to the LT1, except there is another problem, the cam. The L98 cam still won't do quite as well. Even with a better intake setup the cam is still restrictive. Now if you put an L98 with a Mini Ram and an LT1 cam vs. a stock LT1 you'd probably have a VERY close race. I have no idea who it would go to, perhaps the L98 because I've heard it's a better head design? Who knows.

The problem is that we'll never see this race because anybody who installs a new intake on the L98 typically isntalls a much more aggressive cam at the same time, then all bets are off.

Disclaimer: No Scorp's were harmed during the making of this post. I hope you don't mind me using your dyno graph, afterall you're very close to putting those numbers to shame. Be sure and get us some new numbers when you get it all back together. :cheers:


[Modified by Nathan Plemons, 7:54 AM 5/9/2002]

Nathan Plemons

Oops, forgot to summarize my answer.

To answer your question if you install JUST a mini ram yes you will likely be slower. You will give up some low end torque, although I doubt that much, but your cam still won't have the high RPM breathing ability needed to compensate.

Now say if you put a mini ram in there and a healthy cam you'll be very pleased with the results. I know the Hot Cam is not a very popular cam for the miniram, but it does great for the LT1, it should do fine for an L98 with basically an LT1 intake on it. :seeya

Raistlin

ok, first, why not use an LT1 intake instead of the Mini Ram? It's
an intake known (many dyno graphs from forum members, stock and
modified) to give flat torque curves and has the ability to
breath at high rpm. It also handles strokers very well, just look
at all the fast, high hp LT1's on the board.

looking at the cam specs (according to http://www.spoperformanceparts.com)
the L98 cam only loses lift over the LT1 cam and acutally has more
intake duration.


202/206 .403"/.415" 115 87 350ci Corvette and IROC-Z Camaro.

201/208 .447"/.459" NA 1995-97 LT1 Corvette-Camaro.


now the LT1 heads should flow better than the D-port L98 heads,
and will flow better than the earlier L98 heads. Here is where
you will lose hp over the LT1.

the LT1, i believe has higher compression than the L98, with the
exception of the 90-91, which is 10.25. this is only minimal hp
lose, IMO

now stock L98 exhaust is more restrictive than LT1 exhaust, so you'll
lose some more hp there.

so, sticking just an LT1 intake on a stock 90-91 L98, it should
produce less hp than the LT1. You could add 1.6 roller rockers
to increase the lift (don't have time to do the math) and mildly
port/polish L98 d-ports (really need to do that to match the raised
ports of the LT1 intake anyway) and changed the exhaust, i think
you'd have as much hp as the LT1.

Of course, if you're gonna take the heads off, you might as well
put in a bigger cam, say the hot cam, (don't forget to change the
valve springs). I don't see why this combo would preform differently
from a similarly set up LT1, with the only exception, and a big,
important one, being head flow.

just my thoughts, hope this helps

James94LT1

You can't put a LT1 intake on a L98. There is no distributor hole.
Thats why you have to go with the miniram.

:confused:

scorp508

Yes you can. Go here... http://www.lt1intake.com this guy modifies them.

mackeyred96

:cool:

Aggravated4life

I have to say this is a never ending debate but its still a good one.Lots of people come online here and havent been on as long as some of us and havent seen the old debates so its will probably always come up from time to time.

I have to say that nathan explained it excellent and the LT1 is the quicker set up.But keep in mind again,drivers skill has alot to do with 1/4 mile times as well.

However,theres no denying an LT1 makes 50-60 HP more then certain L98's in stock form and the short runner design is the primary reason it does so.(other factors count but theyre already mentioned previously)Its still a torque monster because its torque band is flat and goes across the rpm range.Its total torque helps it go.Low rpm Peak torque looks great on paper and is great for around town and cruising but isnt ideal for someone who wants to build HP for a drag racer.

I would imagine,even though Im a fan of the SR more so,a mini ram would be fine on an L98 as long as you install a good cam with it.Better gears will help it,as it does with the LT1's.SOTP and feel can be decieving as well,which is why one must go to the track after they do their mods to see their true gains.

Ie:My car FEELS fast off the line and is fun to drive with 3.73's but I KNOW it wont set any 1/4 mile records.I really dont care either.When the time comes I do care and want to set it up for drag racing,Ill go with the MR or Modified LT1 intake and ditch the TPI to match the gears and just have fun with it.
I rode in a 88 TPIS MR Iroc with just a cam,stock D port L98 Corvette heads and headers and it was simply a fast car.I loved it.If he did more mods,it wouldve been faster.Torque "FEEL" was just as a good TPI felt off the line.So that was good enough for everyday driving.I dont imagine its going to slow a Vette down any.
:)

James94LT1

Wow, I sure didn't know that! I bet TPIS doesn't like that guy :lol:

85WHITEZ51

I was planning on getting the MR III and use a set of vortec heads and chunk my 85 heads, I already have a free flowing cat back exhaust, gutted cat, and I would get a set of TPIS headers or Hooker headers. I was also going to get a new cam and chip made for my application so it would all work together. With this setup I was just getting concerned that I would lose that fun off the line feeling my L-98 has. Right now I have 3.07 gears with an auto tranny but I woulsoon go to 3.54's. So in conclusion with this setup I should still retain the off the line performance I have now and gain a lot of top end power, right?Thanks for all the help.

Zora

It would have been hard for GM to sell the LT1s.....If the L98s were faster. :yesnod:

General order...L98,LT1,LT4,LS1,etc.... :cheers: